Confucius (551-479 B.C.) was the most influential and respected philosopher in Chinese history. From about 100 B.C. to the revolution of 1911, the ideas of Confucius served as the single strongest influence on Chinese society. These ideas, which are called Confucianism, stress the need to develop moral character and responsibility.

Chinese governments made Confucius' teachings the official state philosophy. Millions of people in China--and in such nearby countries as Japan, Korea, and Vietnam--honored Confucius in much the same way as other peoples honor founders of religions.

Confucius was born in the duchy of Lu, in what is now Shandong Province, China. His real name was Kong Qiu. The name Confucius is a Latin form of the title Kongfuzi, which means Great Master Kong. Confucius' parents died when he was a child. He failed in an attempt to become an adviser to a wise ruler. Confucius had wanted the position so he could put into practice his ideas for reforming society. Confucius received some minor official appointments, but at his death he was largely unknown in China. His disciples spread his teachings.

No book definitely written by Confucius exists. His disciples recorded his conversations and sayings in a book called The Analects.

Confucianism is a philosophy based on the ideas of the Chinese philosopher Confucius. It originated about 500 B.C. From the 100's B.C. to the A.D. 1900's, Confucianism was the most important single force in Chinese life. It influenced Chinese education, government, and personal behavior and the individual's duty to society.

Many people consider Confucianism a religion. But Confucianism has no clergy and does not teach the worship of a God or gods or the existence of a life after death. Confucianism can more accurately be considered a guide to morality and good government.

Early Confucianism. Confucius was born about 551 B.C. At that time, constant warfare raged among the many states that made up China. Rapid political change altered the structure of Chinese society, and large numbers of people no longer respected the established standards of social behavior. Confucius feared that this threat to orderly social life would lead to the destruction of civilization.

Confucius believed his society could be saved if it emphasized sincerity in personal and public conduct. The key to orderly social life was the gentleman. Confucius defined a gentleman not as a person of noble birth, but as one of good moral character. A gentleman was truly reverent in worship and sincerely respected his father and his ruler. He was expected to think for himself, guided by definite rules of conduct. Confucius included many of these rules in sayings. For example, Confucius taught a version of the golden rule--"What you do not wish for yourself, do not do to others". A gentleman also studied constantly and practiced self-examination. He took, as Confucius said, "as much trouble to discover what was right as lesser men take to discover what will pay."

Confucius believed that when gentlemen were rulers, their moral example would inspire those beneath them to lead good lives. Virtuous behavior by rulers, he declared, had a greater effect in governing than did laws and codes of punishment.

When Confucius died about 479 B.C., he was largely unknown. His followers spread his ideas. The most important early Confucian philosophers were Mencius (390-305 B.C.) and Xunzi (mid-200's B.C.). Mencius believed people were born good. He stressed the need to preserve "the natural compassion of the heart" that makes people human. Mencius emphasized the past as an ideal age and a model for examining present problems. In contrast, Xunzi believed people could be good and live together peacefully only if their minds were shaped by education and clear rules of conduct.

By about 200 B.C., the first large, unified Chinese empire had begun. The rulers approved of Confucianism's emphasis on public service and respect for authority. In 124 B.C., the government established the Imperial University to educate future government officials in Confucian ideals. The university based its teachings on five books of Confucian thought called the Five Classics. Mastery of the Classics became proof of moral fitness and the chief sign of a gentleman.

Later Confucianism. The early Confucianists concerned themselves primarily with the needs of society. However, ideas from Taoism and other philosophies helped shift the emphasis to additional areas of human experience. For example, a person's ability to live in harmony with nature was a minor issue to Confucius. But it became an important theme in Confucian thought during the 200's and 100's B.C.

From about A.D. 200 to 600, interest in Confucianism declined in China. Many Chinese turned instead to Buddhism and Taoism. These religions dealt with problems that the teachings of Confucianism largely ignored, such as the meaning of suffering and death.

A revival of interest in Confucius' philosophy began in the 600's. By the 700's, candidates for government jobs had to take a civil service examination based on Confucian ideas. The examination carried out Confucius' belief that an enduring state must be built on the merit of its rulers' advisers.

Zhu Xi (1130-1200) became a leader of a movement called Neo-Confucianism. Zhu developed a branch of Neo-Confucianism called the rational wing. It emphasized study and investigation of Li, the pattern behind human and natural relationships. Scholars led by Wang Yangming (1472-1529) developed the intuitional wing of Neo-Confucianism. They sought enlightenment by a combination of meditation and moral action.

Confucianism continued to actively influence Chinese life until it came into conflict with European ideas, especially Communism, in the 1900's. For many years, the Chinese Communist government opposed Confucianism because the philosophy encouraged people to look to the past rather than to the future. However, official opposition ended in 1977.

Socrates (about 470-399 B.C.) was a Greek philosopher and teacher. Socrates was one of the most original, influential, and controversial figures in ancient Greek philosophy and in the history of Western thought.

Before Socrates, Greek philosophy focused on the nature and origin of the universe. He redirected philosophy toward a consideration of moral problems and how people should best live their lives. Socrates urged his fellow Greeks to consider as the most important things in life the moral character of their souls and the search for knowledge of moral ideas like justice. He was credited with saying "the unexamined life is not worth living." Socrates's teachings, combined with his noble life and calm acceptance of death, have made him the model of what it is to be a philosopher.

The Socratic problem. Because Socrates wrote nothing, our only knowledge of his ideas comes from other Greek writers. The most important sources are the dialogues written by one of his followers, Plato. Also important are the writings of the historian Xenophon; the comedy Clouds, by the playwright Aristophanes; and writings of Plato's pupil Aristotle. The difficulty of determining the character and beliefs of Socrates based on these sources is referred to as "the Socratic problem". The most common understanding of Socrates comes from Plato's dialogues, which communicate the force of Socrates's intellect and character. Plato's Apology of Socrates is regarded as a reliable representation of Socrates's defense of his life at his trial.

Socrates's life. Socrates was born near Athens, and spent most of his life in Athens. His wife, Xanthippe, was supposedly ill-tempered. They had three sons. Socrates spent most of his time in conversations with a wide range of Athenians, but mostly with young men. Plato distinguished Socrates from the professional teachers of the day, who were called Sophists. Plato emphasized that Socrates did not accept money from his listeners. As a result, Socrates was very poor. Socrates was famous for his self-control and also for his indifference to physical comfort. Supposedly, he once stood in one spot for a day and night puzzling over a philosophical problem.

Many Athenians were annoyed by Socrates's constant examination of their moral assumptions. Plato showed Socrates engaging leading Athenian citizens in conversation. They entered the conversations believing that they knew the nature of such virtues as piety or courage. But Socrates soon showed them that their beliefs were contradictory or confused. He also criticized some assumptions of the Athenian democratic system. Hostility arose in Athens toward Socrates. At the age of 70, Socrates was brought to trial and charged with "not believing in the gods the state believes in, and introducing different new divine powers; and also for corrupting the young". Socrates was convicted and sentenced to death. He could have escaped from prison, but he felt morally obligated to follow the court's decision, even if it was unjust. His arguments for his action are recorded in Plato's Crito. Plato's Phaedo describes Socrates's calm in the face of death and his drinking of the poison, hemlock, which the Athenians used for the death penalty.

Although Socrates's conviction was unjust, there was some truth to the charges against him. Socrates apparently observed the religious rites of Athens and believed in divine power. But Plato's Euthyphro indicates that Socrates would not accept stories that showed the gods acting immorally. Socrates also claimed to have received a "divine sign" that kept him from committing immoral actions. Also, his repeated demonstration of the weak reasoning behind most people's moral beliefs could be seen as teaching the young to reject the morals accepted by society. In fact, Socrates's ultimate goal was to encourage people to devote their lives to considering how to live morally.

The Socratic method. As a philosopher, Socrates is more important for his philosophical methods than for any specific doctrine. The dialogue form was probably invented by Plato to portray the Socratic method or dialectic. The method consisted of asking questions like "What is courage?" of people who were confident of the answer. Socrates, claiming ignorance of the answers to the questions, would gradually show the people's beliefs to be contradictory. Socrates did not answer his questions, though much could be learned from the course of the discussion.

Socrates was the first philosopher to make a clear distinction between body and soul and to place higher value on the soul. His examination of such moral ideas as piety and courage represent an important first attempt to arrive at universal definitions of terms. He believed that a person must have a knowledge of moral ideas to act morally.

Plato, (427-347 B.C.), was a philosopher and educator of ancient Greece. He was one of the most important thinkers and writers in the history of Western culture.

Plato's life. Plato was born in Athens. His family was one of the oldest and most distinguished in the city. His mother, Perictione, was related to the great Athenian lawmaker Solon. His father, Ariston, died when Plato was a child. Perictione married her uncle, Pyrilampes, and Plato was raised in his house. Pyrilampes had been a close friend and supporter of Pericles, the statesman who brilliantly led Athens in the mid-400's B.C.

As a young man, Plato wanted to become a politician. In 404 B.C., a group of wealthy men, including two of Plato's relatives--his cousin Critias and his uncle Charmides--established themselves as dictators in Athens. They invited Plato to join them. However, Plato refused the offer because he was disgusted by the group's cruel and unethical practices. In 403 B.C., the Athenians deposed the dictators and established a democracy. Plato reconsidered entering politics. But he was again repelled when his friend, the philosopher Socrates, was brought to trial and sentenced to death in 399 B.C. Deeply disillusioned, Plato left Athens and traveled for a number of years.

In 387 B.C., Plato returned to Athens and founded a school of philosophy and science that became known as the Academy. The school stood in a grove of trees that, according to legend, was once owned by a Greek hero named Academus. Some scholars consider the Academy to have been the first university. Such subjects as astronomy, biological sciences, mathematics, and political science were investigated there. Except for two trips to the city of Syracuse in Sicily in the 360's B.C., Plato lived in Athens and headed the Academy for the rest of his life. His most distinguished pupil at the Academy was the Greek philosopher Aristotle.

Plato's writings

The dialogues. Plato wrote in a literary form called the dialogue. A dialogue is a conversation between two or more people. Plato's dialogues are actually dramas that are primarily concerned with the presentation, criticism, and conflict of philosophical ideas. The characters in his dialogues discuss philosophical problems and often argue the opposing sides of an issue. Plato achieved a dramatic quality through the interaction of the personalities and views of his characters. These dramas of ideas have much literary merit. Many scholars consider Plato the greatest prose writer in the Greek language--and one of the greatest in any language.

Plato's better-known dialogues include The Apology, Cratylus, Crito, Euthyphro, Gorgias, The Laws, Meno, Parmenides, Phaedo, Phaedrus, Protagoras, The Republic, The Sophist, The Symposium, Theaetetus, and Timaeus. A complete edition of Plato's works, collected in ancient times, consists of 36 works--35 dialogues and a group of letters. Scholars today generally agree that about 30 of the dialogues and several of the letters were actually written by Plato. Scholars have also determined to a great extent the order in which the dialogues were written. Thus, Plato's development as a writer and thinker can be traced.

The early dialogues are dominated by Socrates, who appears as a major figure in each. These dialogues include Charmides, Euthyphro, Ion, and Laches. In these dialogues, Socrates questions people who claim to know or understand something about which Socrates claims to be ignorant. Typically, Socrates shows that the other people do not know what they claim to know. Socrates does not provide answers to the questions. He shows only that the answers proposed by the other characters are inadequate. Most scholars consider these so-called Socratic dialogues to be fairly accurate portrayals of the actual philosophic style and views of Socrates. See SOCRATES (The Socratic method).

The later dialogues. In the later dialogues, Plato uses the character of Socrates merely as his spokesman. These dialogues include The Republic, The Sophist, and Theaetetus. In these works, Socrates criticizes the views of others and presents complex philosophical theories. Thus, the later dialogues offer more complete and positive answers to questions being considered than do the early dialogues. But they lack much of the dramatic and literary quality of the earlier writings.

Plato's philosophy

The theory of forms. Many of Plato's dialogues try to identify the nature or essence of some philosophically important notion by defining it. The Euthyphro revolves around a discussion and debate of the question, "What is piety?" The central question of The Republic is, "What is justice?" The Theaetetus tries to define knowledge. The Charmides is concerned with moderation, and the Laches discusses valor. Plato denied that a notion, such as piety (reverence), could be defined simply by offering examples of it. Plato required a definition of a notion to express what is true of, and common to, all instances of that notion.

Plato was interested in how we can apply a single word or concept to many different things. For example, how can the word table be used for all the individual objects that are tables? Plato answered that various things can be called by the same name because they have something in common. He called this common factor the thing's form or idea.

According to Plato, the real nature of any individual thing depends on the form in which it "participates". For example, a certain object is a triangle because it participates in the form of triangularity. A particular table is what it is because it participates in the form of the table.

Plato insisted that the forms differ greatly from the ordinary things that we see around us. Ordinary things change, but their forms do not. A particular triangle may be altered in size or shape, but the form of triangularity can never change. In addition, individual things only imperfectly approximate their forms, which remain unattainable models of perfection. Circular objects or beautiful objects are never perfectly circular or perfectly beautiful. The only perfectly circular thing is the form of circularity itself, and the only perfectly beautiful thing is the form of beauty.

Plato concluded that these unchanging and perfect forms cannot be part of the everyday world, which is changing and imperfect. Forms exist neither in space nor time. They can be known only by the intellect, not by the senses. Because of their stability and perfection, the forms have greater reality than ordinary objects observed by the senses. Thus, true knowledge is the knowledge of forms. These central doctrines of Plato's philosophy are called his theory of forms or theory of ideas.

Ethics. Plato based his ethical theory on the proposition that all people desire happiness. Of course, people sometimes act in ways that do not produce happiness. But they do this only because they do not know what actions will produce happiness. Plato further claimed that happiness is the natural consequence of a healthy state of the soul. Because moral virtue makes up the health of the soul, all people should desire to be virtuous. Plato said that people sometimes do not seek to be virtuous, but only because they do not realize that virtue produces happiness.

Thus, for Plato, the basic problem of ethics is a problem of knowledge. If a person knows that moral virtue leads to happiness, he or she naturally acts virtuously. Plato differed from many Christian philosophers who have tended to view the basic problem of ethics as a problem of the will. These philosophers argue that often people know what is morally right, but face their greatest problem in willing to do it.

Plato argued that it is worse to commit an injustice than to suffer one, because immoral behavior is the symptom of a diseased soul. It is also worse for a person who commits an injustice to go unpunished than to be punished, because punishment helps cure this most serious of all diseases.

Psychology and politics. Plato's political philosophy, like his ethics, was based on his theory of the human soul. He argued that the soul is divided into three parts: (1) the rational part, or intellect; (2) the spirited part, or will; and (3) appetite or desire. Plato argued that we know the soul has these parts because they occasionally conflict with each other. For example, a person may desire something but fight this desire with the power of the will. In a properly functioning soul, the intellect--the highest part--should control the appetite--the lowest part--with the aid of the will.

Plato described the ideal state or society in The Republic. Plato wrote that, like the soul, this state or society has three parts or classes: (1) the philosopher kings, who govern the society; (2) the guardians, who keep order and defend the society; and (3) the ordinary citizens, farmers, merchants, and craftworkers who provide the society's material needs. The philosopher kings represent the intellect, the guardians represent the will, and the ordinary citizens represent the appetites. Plato's ideal society resembles a well-functioning soul because the philosopher kings control the citizens with the aid of the guardians.

Immortality of the soul. Plato believed that though the body dies and disintegrates, the soul continues to live forever. After the death of the body, the soul migrates to what Plato called the realm of the pure forms. There, it exists without a body, contemplating the forms. After a time, the soul is reincarnated in another body and returns to the world. But the reincarnated soul retains a dim recollection of the realm of forms and yearns for it. Plato argued that people fall in love because they recognize in the beauty of their beloved the ideal form of beauty that they dimly remember and seek.

In the Meno, Plato has Socrates teach an ignorant slave boy a truth of geometry by simply asking a series of questions. Because the boy learns this truth without being given any information, Plato concluded that learning consists of recalling what the soul experienced in the realm of the forms.

Art. Plato was critical of art and artists. He urged strict censorship of the arts because of their influence on molding people's characters. Using his theory of forms, Plato compared artists unfavorably with craftworkers. He declared that a table made by a carpenter is an imperfect copy of the ideal form of a table. A painting of a table is thus a copy of a copy--and twice removed from the reality of the ideal form.

Plato claimed that artists and poets cannot usually explain their works. Since artists do not even seem to know what their own works mean, Plato concluded that they do not create because they possess some special knowledge. Rather, he believed that artists create because they are seized by irrational inspiration, a sort of "divine madness".

Plato's place in Western thought

After Plato died, his nephew Speusippus took over the leadership of the Academy. The school operated until A.D. 529. That year, the Byzantine Emperor Justinian I closed all the schools of philosophy in Athens because he felt they taught paganism. However, Plato's influence was not confined to the Academy. Plato's philosophy deeply influenced Philo, an important Jewish philosopher who lived in Alexandria shortly after the birth of Christ. During the A.D. 200's in Rome, Plotinus developed a philosophy based on Plato's thought. This new version of Plato's philosophy, known as Neoplatonism, had great influence on Christianity during the Middle Ages.

Plato dominated Christian philosophy during the early Middle Ages through the writings of such philosophers as Boethius and Saint Augustine. During the 1200's, Aristotle replaced Plato as the greatest philosophical influence on the Christian world. A revival of interest in Plato developed during the Renaissance. During the 1400's, the Medici family, famous patrons of the arts, established a Platonic Academy in Florence as a center for the study of Plato's philosophy. In the mid-1600's, an important group of English philosophers at Cambridge University became known as the Cambridge Platonists. They used the teachings of Plato and the Neoplatonists to try to harmonize reason with religion.

Aristotle, (384-322 B.C.), a Greek philosopher, educator, and scientist, was one of the greatest and most influential thinkers in Western culture. Aristotle was probably the most scholarly and learned of the classical or ancient Greek philosophers. He familiarized himself with the entire development of Greek thought preceding him. In his own writings, Aristotle considered, summarized, criticized, and further developed all the intellectual tradition that he had inherited. Aristotle and his teacher Plato are usually considered to be the most important ancient Greek philosophers.

Aristotle's life

Aristotle was born in Stagira, a small town in northern Greece. His father, Nichomachus, was the personal physician of Amyntas II, the king of nearby Macedonia. Amyntas was the father of Philip of Macedonia and the grandfather of Alexander the Great. Aristotle's parents died when he was a boy, and he was then raised by a guardian named Proxenus.

When Aristotle was about 18 years old, he entered Plato's school in Athens, known as the Academy. He remained there for about 20 years. Plato recognized Aristotle as the Academy's brightest and most learned student, and called him the "intelligence of the school" and the "reader."

When Plato died in 347 B.C., Aristotle left the Academy to join a group of Plato's disciples living with Hermeias, a former student at the Academy. Hermeias had become ruler of the towns of Atarneus and Assos in Asia Minor. Aristotle stayed with Hermeias for about three years and married the ruler's adopted daughter, Pithias.

In 343 or 342 B.C., Philip II, king of Macedonia, invited Aristotle to supervise the education of his young son Alexander. Alexander later conquered all of Greece, overthrew the Persian Empire, and became known as Alexander the Great. Alexander studied under Aristotle until 336 B.C., when the youth became ruler of Macedonia after his father was assassinated.

About 334 B.C., Aristotle returned to Athens and founded a school called the Lyceum. Aristotle's school, his philosophy, and his followers were called peripatetic, taken from the Greek word meaning walking around, because Aristotle taught while walking with his students.

Soon after Alexander died in 323 B.C., Aristotle was charged with impiety (lack of reverence for the gods) by the Athenians. They probably resented his friendship with Alexander, the man who had conquered them. Aristotle had not forgotten the fate of the philosopher Socrates, condemned to death on a similar charge by the Athenians in 399 B.C. He fled to the city of Chalcis so the Athenians would not, as he said, "sin twice against philosophy." He died in Chalcis a year later.

Aristotle's writings Aristotle's writings are usually divided into three groups: (1) popular writings, (2) memoranda, and (3) treatises.

The popular writings were mostly dialogues modeled on Plato's dialogues and produced while Aristotle was still at Plato's Academy. These works were intended for a general audience outside the school, rather than for philosophers at the school. For this reason, Aristotle referred to them as his exoteric writings (exo- means outside in Greek). These writings have not survived, but the works of later writers include many references to them and quotations from them.

The memoranda were largely collections of research materials and historical records. Prepared by Aristotle and his students, they were intended as sources of information for scholars. With few exceptions, the memoranda, like the popular writings, were lost.

The treatises make up nearly all of Aristotle's surviving writings. They were probably written for use either as lecture notes or as textbooks at the Lyceum. Unlike the popular works, the treatises were intended only for students in the school. Thus, the treatises are called Aristotle's esoteric works (eso- means inside in Greek).

Aristotle's philosophy

Logic. Aristotle's works on logic are collectively called the Organon, which means instrument, because they investigate thought, which is the instrument of knowledge. The Organon includes The Categories, The Prior and Posterior Analytics, The Topics, and On Interpretation. Aristotle was the first philosopher to analyze the process whereby certain propositions can be logically inferred to be true from the fact that certain other propositions are true. He believed that this process of logical inference was based on a form of argument he called the syllogism. In a syllogism, a proposition is argued or logically inferred to be true from the fact that two other propositions are true. For example, from the facts that (1) all people are mortal and (2) Socrates is a person, it can be logically argued that (3) Socrates is mortal. The syllogism continued to play an important role in later philosophy.

Philosophy of nature. For Aristotle, the most striking aspect of nature was change. He even defined the philosophy of nature in his Physics as the study of things that change. Aristotle argued that to understand change, a distinction must be made between the form and matter of a thing. For example, a sculpture might have the form of a human being, and bronze as its matter. Aristotle believed that change essentially consists of the same matter acquiring new form. In our example, change occurs if the bronze sculpture is molded into a new form.

To better understand change, Aristotle studied its causes. He distinguished four kinds of causes: (1) material, (2) efficient, (3) formal, and (4) final. The material cause of the sculpture is the material of which it is made. Its efficient cause is the activity of the sculptor who made it. Its formal cause is the form in which the bronze is molded. Its final cause is the plan or design in the sculptor's mind.

Aristotle studied movement as a kind of change and wrote about the movement of the heavenly bodies in On the Heavens. In On Coming-to-be and Passing-away, he investigated the changes that occur when something seems to be created or destroyed.

Aristotle's philosophy of nature includes psychology and biology. In On the Soul, he investigated the various functions of the soul and the relationship between the soul and the body. Aristotle was the world's first great biologist. He gathered vast amounts of information about the variety, structure, and behavior of animals and plants. Aristotle analyzed the parts of living organisms teleologically, that is, in terms of the purposes they serve.

Metaphysics. In his Metaphysics, Aristotle tried to develop a science of things that never change and investigate the most general and basic principles of reality and knowledge. Since the most important of these unchanging things is God, Aristotle sometimes called this science theology, the study of God. He also called this branch of his philosophy first philosophy, because of its fundamental importance. Aristotle himself never used the name metaphysics, which literally means after the physics. This name was given to the work centuries later simply because it followed the Physics in the written edition of Aristotle's works. But the word metaphysics has now come to mean any philosophic study of the basic principles of reality and knowledge.

Ethics and politics. For Aristotle, ethics and politics both study practical knowledge, that is, knowledge that enables people to act properly and live happily. Aristotle's works on this subject include the Nicomachean Ethics and the Politics.

Aristotle argued that the goal of human beings is happiness, and that we achieve happiness when we fulfill our function. Therefore, it is necessary to determine what our function is. The function of a thing is what it alone can do, or what it can do best. For example, the function of the eye is to see, and the function of a knife is to cut. Aristotle declared that a human being is "the rational animal" whose function is to reason. Thus, according to Aristotle, a happy life for human beings is a life governed by reason.

Aristotle believed that a person who has difficulty behaving ethically is morally imperfect. His ideal person practices behaving reasonably and properly until he or she can do so naturally and without effort. Aristotle believed that moral virtue is a matter of avoiding extremes in behavior and finding instead the mean between the extremes. For example, the virtue of courage is the mean between the vices of cowardice at one extreme and foolhardiness at the other. Similarly, the virtue of generosity is the mean between stinginess and wastefulness.

Literary criticism. Aristotle's Poetics has probably been the single most influential work in all literary criticism. The Poetics examines the nature of tragedy, and takes as its prime example Sophocles' tragedy Oedipus Rex. Aristotle believed that tragedy affects the spectator by arousing the emotions of pity and fear, and then purifying and cleansing the spectator of these emotions. He called this process of purifying and cleansing catharsis.

Aristotle's place in Western thought

After Aristotle's death, his philosophy continued to be taught at the Peripatetic school by a long line of successors. One of these philosophers, Critolaus, went to Rome in 155 B.C. and gave the Romans their first contact with Greek philosophy. About 50 B.C., Andronicus of Rhodes edited Aristotle's works. This edition stimulated much scholarly analysis of Aristotle's philosophy, particularly in Alexandria. From about A.D. 500 to 1100, knowledge of his philosophy was almost completely lost in the West. During this period, it was preserved by Arab and Syrian scholars who reintroduced it to the Christian culture of Western Europe in the 1100's and 1200's.

Aristotle enjoyed tremendous prestige during this time. To some leading Christian, Jewish, and Arab scholars of the Middle Ages, his writings seemed to contain the sum total of human knowledge. Saint Thomas Aquinas, one of the most influential philosophers of the Middle Ages, considered Aristotle "the philosopher". Dante Alighieri, perhaps the greatest poet of the Middle Ages, called Aristotle the "master of those who know".

Aristotle's authority has declined since the Middle Ages, but many philosophers of the modern period owe much to him. The extent of Aristotle's influence is difficult to judge, because many of his ideas have been absorbed into the language of science and philosophy.

Zeno of Citium, (335-265 B.C.), was the founder of Stoic philosophy in Athens. He was born in Citium on the island of Cyprus. It is reported that he was originally a merchant, but was shipwrecked and lost all his property traveling to Athens in 314 B.C. He stayed there and took up the study of philosophy, meeting his students on a stoa (porch), from which the name stoic came

He went to Athens and was impressed both by the Cynics and by the Megarian logicians. He advocated a life that "followed reason"--that was free from passion, dignified, and self-respecting. His ethical doctrine was very austere: either one was a good person (a Stoic sage) in every way or, if there were any shortcomings, one was totally without virtue. Zeno taught that the human soul was not complex but was truly only reason (logos); the rest--ambition, fear, appetite--ought to be eliminated and was not in any way part of the self.

Zeno taught that it is foolish to try to shape circumstances to our desires. The world process is not like a blindly running machine. Instead, a divine intelligence guides and governs it, and directs all things ultimately toward what is good. Wise people will "follow nature" and fit their desires to the pattern of events. They will find happiness in freedom from desire, from fear of evil, and in knowing that they are in tune with the divine purpose directing all things. The Stoic philosophy spread to Rome and flourished there for several centuries after the birth of Christ.

Cicero, Marcus Tullius, (106-43 B.C.), was a great Roman orator and statesman. His written orations and philosophical and religious essays made him one of the most influential authors in Latin literature. In his writings, Cicero translated ideas and technical terms into Latin that had previously existed only in Greek. Cicero so improved Latin that it served as the international language of intellectual communication for centuries.

His life. Cicero was born of middle-class parents in Arpinum, Italy. He studied philosophy, rhetoric, and Greek and Latin literature in Rome, Athens, and Rhodes.

Cicero gained fame in 70 B.C., when he successfully prosecuted Gaius Verres, a corrupt former governor of Sicily. Cicero's victory in this trial earned him the approval of the Roman aristocracy. With the support of the aristocracy, Cicero attained the position of consul, Rome's highest elected political office, in 63 B.C.

The First Triumvirate of Julius Caesar, Gnaeus Pompey, and Marcus Licinius Crassus banished Cicero from Rome in 58 B.C. because he opposed their rule. Cicero was allowed to return to Rome in 57 B.C. The Second Triumvirate of Octavian (later the Emperor Augustus), Marcus Aemilius Lepidus, and Mark Antony would not tolerate Cicero's opposition. They had him killed.

His works. Cicero composed more than 100 orations. They are known for their precise choice of words; attention to grammatical structures; and skillful use of descriptions, narration, and prose rhythms. Two series of orations reflect Cicero's support for the republican form of government. In 63 B.C., he delivered four speeches against a Roman named Catiline who plotted to overthrow the Roman government. These speeches led to the defeat and death of Catiline and his followers. In 44 and 43 B.C., Cicero composed 14 speeches called the Philippics. In them, he attacked Mark Antony because he believed Antony intended to rule Rome with absolute power.

Cicero composed two major works on oratory, Brutus and De Oratore. He described the advantages of a serene old age in De Senectute, and he analyzed friendship in De Amicitia. Cicero examined ethical behavior in De Finibus and the nature of the gods in De Natura Deorum. Cicero discussed the attainment of happiness in Tusculan Disputations and one's duties in life in De Officiis. The influence of the Greek philosopher Plato appears in a book on law called De Legibus and a study of various forms of government called De Republica. Cicero was also an active letter writer. His correspondence reveals his informal side. Cicero's letters also provide valuable accounts of Roman life.

Marcus Aurelius, (A.D. 121-180), was a Roman emperor and philosopher. He became a follower of Stoicism, a school of philosophy that originated in Greece about 300 B.C. Marcus wrote a series of thoughts that were collected and published as Meditations. This work is an intimate self-portrait and a classic of Stoic philosophy.

Marcus was born in Rome to a noble family. Before Antoninus Pius became emperor in A.D. 138, he adopted Marcus and Lucius Verus. Marcus became emperor in 161 and named Lucius co-emperor. Marcus and Lucius ruled jointly until Lucius' death in 169. During much of Marcus' reign, the Roman Empire suffered from epidemics, revolts, and frequent wars along its frontiers. Marcus turned to Stoic philosophy for personal comfort.

Marcus accepted the Stoic belief that the world is ruled by a benevolent universal force. He was inspired by the Stoic belief in the harmony of natural and moral law that represented the divine spirit present in all things. Marcus believed that the soul did not survive after death, but instead was reabsorbed into the universe. He saw this reabsorption as a reason to accept death calmly. Marcus hated selfishness and taught himself to ignore or forgive offenses. Perhaps his noblest quality was his sense of responsibility to humanity and his belief that all people are citizens of the universe and should live for each other.

Epictetus, (A.D. 50-138), was a Greek Stoic philosopher. He taught that we should not demand that events happen as we want. We should instead want them to happen as they do.

His Manual and Discourses, as recorded and edited by his pupil Arrian, stress his opinion that philosophy is a way of life rather than an art of using words. He held that since the events of the world are all determined by providence and thus beyond our control, individuals must try to accept whatever happens calmly and dispassionately. Epictetus also argued, however, that individuals are totally responsible for their deeds and must learn how to judge their actions by rigorous daily self-examination. The "wise man" will recognize that he has a duty toward society and his fellow humans, for all humans are alike and entitled to basic rights.

A wise, divine Providence governs all things, so that what seem to be calamities are really parts of a divine plan that orders everything for the best. Epictetus thought that only foolish people are upset by events they cannot control. The true Stoic can face even death and all so-called misfortunes with perfect calm.

Epictetus was born in Asia Minor, and was a slave in his youth. He became free, and lived and taught in Rome until A.D. 89, when the Emperor Domitian expelled the philosophers. Epictetus spent the rest of his life teaching in Nicopolis, Greece.

Epicurus, (342?-270 B.C.), was a Greek philosopher. His views on pleasure, freedom, and friendship had a great influence in the Greco-Roman world. The word epicurean comes from his name.

Epicurus believed that the human mind was disturbed by two main anxieties: fear of deities (gods and goddesses) and fear of death. He believed both fears were based on mistaken beliefs and could be overcome by the study of physics. According to Epicurus, physics proves that the movements of the heavens and meteorological phenomena are caused by the motions of atoms, not by deities. He said deities should not be feared because they are not concerned with human affairs.

Epicurus said that death should not be feared because good and evil lie in sensation, and death ends sensation. According to Epicurus, the soul is composed of atoms and these atoms disperse at death. Freed from anxieties over death, a person can live the good life by seeking moderate pleasures and avoiding pain. The modern term epicurean suggests excessive bodily pleasures, but Epicurus taught that pleasure can best be gained by living in accordance with prudence, moderation, courage, and justice, and by making friends.

Epicurus was born on the island of Samos. Except for three letters that summarize his teachings, his philosophy has been reconstructed from fragments of his many works and the poem On the Nature of Things by Lucretius.

Pyrrho of Elis, (361-270 B.C.), was the founder of Skepticism. Skepticism was a philosophical movement of ancient Greece. Pyrrho, from whom Pyrrhonism takes its name, believed that tranquillity and happiness result from the realization that all perceptions and judgments are relative and that genuine knowledge is the unattainable. Pyrrho left no writings, but a pupil preserved some of his teachings. He traveled widely and learned many different philosophic viewpoints, each one claiming to be the truth. Because not all viewpoints could be right, Pyrrho decided to suspend judgment about truth, right, and wrong. Custom and convention, he felt, were the only guides to what is just or unjust. Even our senses tell us only how things appear, not what they really are. Pyrrho was born at Elis, Greece.

Plotinus, (205-270), was the founder of a school of Greek philosophy known as Neoplatonism. He developed Neoplatonism from the philosophy of Plato. Plotinus said that the material world is unreal, politics trivial, the body a temporary prison for the soul, and life a journey through a landscape of illusion. Reality lay "yonder" in a solitary perfect being, The One, the source of all truth, goodness, and beauty. He said pure souls may hope to "return" there. Sometimes this return occurred as a mystical vision. Plotinus believed he had experienced such a vision.

Plotinus developed an interpretation of Plato's philosophy that changed the position of the Platonic Academy from one of skepticism into a new religious view. He agreed with the skeptics that knowledge is required in order to grasp the Platonic forms that are "beyond" the physical heavens. He argued, however, that humans do have knowledge and concluded that in order to acquire it souls must somehow journey to this "transcelestial" place to see the forms there.

The system of Plotinus has as its highest form "the One", an indefinable ultimate principle. By an overflow (emanation) from itself, the One creates a second order, Reason and the Forms; this level, in its turn, generates the level of Soul. The final level, that of matter, is dark and unreal, and the goal of the human soul is to escape that level and return to the One. The return becomes possible through ascetic moral training and the contemplation of beauty; if these are practiced purely, one can reestablish the connection of the Soul with Reason and ultimately, through a mystical experience (which Plotinus described variously as "ecstasy," "self-surrender," and "flight yonder, of the alone to the Alone"), arrive at knowledge of, and therefore unification with, the One.

The doctrines of Plotinus, which rejected the despairing materialism and compulsive search for luxury of the Roman Empire, became the official position of the Platonic Academy and exercised strong influence on both Christian theology and Islamic thought.

Plotinus may have been born in Egypt. He joined a military campaign to the East to try to learn more about Indian philosophy. Plotinus spent the last years of his life teaching in Rome. He disliked writing but dictated 54 lectures in six 9-lecture sets called the Enneads. His pessimism reflects only one side of Plato's philosophy--that in which philosophy is seen as a consolation or as an escape from the world. But this was the side most appealing to Romans of Plotinus's time.

Augustine, Saint (354-430), was one of the greatest leaders of the early Christian church. His writings had a strong influence on medieval religious thought. Augustine's ideas also appeared in the teachings of John Calvin, Martin Luther, and other Protestant reformers. He influenced such philosophers as Immanuel Kant and Blaise Pascal.

His life. Augustine was born in Tagaste, a city near what is now Constantine, Algeria. His name in Latin was Aurelius Augustinus. His mother, Saint Monica, was a devout Christian. His father was a pagan. As a young man, Augustine pursued worldly success and was attracted to several non-Christian movements. He described his early life and spiritual struggles in Confessions, one of the first great autobiographies.

In the early 380's, Augustine taught rhetoric in Carthage and Rome and then in Milan, Italy. Some friends in Milan encouraged him to read the works of the Greek philosophers called neoplatonists. These writings and the sermons of Saint Ambrose, the bishop of Milan, helped him overcome the intellectual obstacles to accepting Christianity. In 386, Augustine decided to devote himself to the faith, and Ambrose baptized him the next year.

Soon afterward, Augustine returned to Tagaste, where he organized a community of believers. In 391, he traveled to nearby Hippo. The Christian congregation there persuaded him to stay. He was ordained as a priest in Hippo in 391. From 396 until his death, he served as bishop of Hippo.

His beliefs can be divided into three main groups: (1) God and the soul, (2) sin and grace, and (3) the church and the sacraments.

God and the soul. Augustine's study of neoplatonism convinced him that God is present in the soul of every human being. He believed that people should direct their attention to God and not be distracted by the cares and pleasures of the world.

Sin and grace. Augustine preached that people could not change their sinful ways unless helped by the grace of God. He believed that God chooses only certain individuals to receive His grace. This belief forms part of a doctrine called predestination or election.

The church and the sacraments. Augustine believed that people could not receive God's grace unless they belonged to the church and received the sacraments. A group of clergymen in northern Africa said grace could not be given unless the clergy itself was perfect. But Augustine declared that God could by-pass human weaknesses through the sacraments. Augustine's book The City of God presents the history of humanity as a struggle between people who depend on God and those who rely on themselves.

Lombard, Peter (1095-1160), was a medieval theologian who wrote an important theological textbook, The Four Books of Sentences. Composed between 1148 and 1158, the Sentences served as the fundamental textbook for beginners in theology for more than 350 years. It is basically an orderly compilation of Christian doctrine based on Scripture and the teachings of the Fathers of the Church. The contents follow the articles of the Creed: book 1 is on the Trinity; book 2 is on creation and sin; book 3 is on the Incarnation and the virtues; and book 4 is on the sacraments and the Four Last Things. The Sentences met with opposition from more traditional theologians; thus, Walter of Saint-Victor regarded Peter as one of the four "pests of France" responsible for creating scholasticism.

In the Sentences, Lombard presented past and current opinions on theological problems in a systematic way. He compiled these opinions from a number of leading church authorities, especially Saint Augustine. Lombard also summarized the church's position and wrote his own views on the issues. For centuries, students of theology were required to comment on the Sentences. Some of these commentaries were the major works of leading medieval theologians and philosophers, including Saint Bonaventure, John Duns Scotus, and William of Ockham.

Lombard was born near Novara, Italy, and studied in Bologna. About 1134, he went to Paris and taught in the cathedral school of Notre Dame. Lombard quickly gained fame as a theologian and author. In 1159, he was appointed bishop of Paris.

Abelard, Peter (1079-1142), was one of the leading philosophers and theologians of the Middle Ages. But he is probably best known for his love affair with Heloise, a gifted young Frenchwoman.

Abelard was born near Nantes, France. His father, a nobleman, planned a military career for him, but Abelard became a scholar. From 1113 to 1118, he taught theology in Paris. There, Abelard founded a school that, along with two others, developed into the University of Paris.

In 1113, Abelard became the tutor of Heloise, the niece of an official of the Cathedral of Notre Dame. A love affair developed between Abelard and the girl, and she became pregnant. Soon after the birth of their baby in 1118, Heloise and Abelard were secretly married. Fulbert, Heloise's uncle, learned of the love affair and marriage and was outraged. In anger, Fulbert hired several men who broke into Abelard's house and castrated him. Soon after the attack, Abelard and Heloise separated. Abelard became a monk, and Heloise joined an order of nuns. The fame of their tragic love affair resulted largely from the many letters they exchanged.

Abelard's major contributions to medieval thought were in the areas of logic and theology. He urged the use of logic in order to understand and defend Christianity. Abelard compiled a book called Sic et Non (Yes and No). It consisted of the conflicting views of theological authorities on various religious problems and principles. The work became an influential textbook in the medieval philosophical system called scholasticism . Abelard also wrote an important book on ethics and The Story of My Misfortunes, a revealing autobiography.

In the philosophical controversy over universals, Abelard rejected both the extreme realism of William of Champeaux and the crude nominalism of Roscellin. While denying that universals are real things, he asserted that they are more than mere words since they express factors common to individual, real things; thus, universals are tools of logic, the basis for logical predication. This position is essentially Aristotelian, although Abelard had only limited access to the works of Aristotle through the translations of Boethius. Abelard's moderate realism in philosophy, his development of the dialectical method of argument, his familiarity with the Bible and many of the Church Fathers, and his intellectual brilliance--rather than any systematic presentation of Christian theology aided by reason--make him one of the important, although much neglected, pioneers of scholasticism.

Albertus Magnus, Saint (1206-1280), was a German-born Christian theologian, philosopher, and scientist. His importance lies in his awareness of the difference between theology and philosophy and between revealed truth and experimental science. He believed that different areas of knowledge follow different sets of laws and require different methods of investigation.

Albertus was advanced for his time in his knowledge of the sciences. He wrote about many scientific subjects, including astronomy, chemistry, geography, and physiology, using his own scientific observations. He devoted much of his time to popularizing the writings of the ancient Greek philosopher Aristotle. Albertus wrote a large number of commentaries on Aristotle's philosophy. These writings influenced Saint Thomas Aquinas, Albertus's most famous pupil, and other theologians known as scholastics

Albertus Magnus was born into a noble family in Lauingen, near Ulm. He attended the University of Padua in Italy, where he joined the Dominican religious order in 1223. He studied and taught at a number of European universities but spent most of his time in Cologne, Germany. Albertus served as a high-ranking Dominican official in Germany, as a bishop, and as a representative of the pope. His feast day is November 15. Albertus is the patron saint of students of the natural sciences.

Alexander of Hales, (1186 - 1245), known as Doctor Irrefragabilis was an English scholastic philosopher and theologian. He began his formal training in arts, philosophy, and theology at the University of Paris when he was 15 years old and became in 1220) the first to lecture as a master on the Sentences of Peter Lombard. After a long and illustrious career, he became a Franciscan friar in 1236 at the age of 50. With him came the right to a chair of theology at the University of Paris, the first and only chair the Franciscans held. Under him the Franciscan John of la Rochelle became master and probably assembled the Summa Fratris Alexandri, which influenced the formation of a Franciscan school, notably through St. Bonaventure. Alexander of Hales introduced Aristotelian principles into Christian theological discussion.

Aquinas, Saint Thomas (1225-1274), was one of the greatest medieval philosophers and theologians. Through the centuries, he has influenced Christian--especially Roman Catholic--thought.

His life. Thomas was born of a noble family in Roccasecca, Italy, near Cassino. He attended the University of Naples from 1239 until 1244, when he joined the Dominican order. He was ordained a priest in 1250. From 1245 to 1252, he studied philosophy and theology under the German theologian Saint Albertus Magnus. In 1256, Thomas was named professor of theology at the University of Paris. There, he became famous because he developed his intellectual talents in the service of the Christian faith.

In 1258, Thomas began to write the Summa contra Gentiles. In this work, he tried to convince non-Christians that the doctrines of Christianity were not contrary to reason. From 1259 to 1268, Thomas wrote commentaries on many writings of the ancient Greek philosopher Aristotle. In 1265, he began to write his most famous work, Summa Theologica, in which he tried to systematically explain Christian theology. But Thomas had a mystical experience in 1273 that caused him to stop writing. He said that all he had written seemed like straw compared with what he had seen in this experience. Thomas' feast day is January 28.

His thought. Thomas combined Aristotle's teachings with Christian doctrine. For example, Thomas argued that no conflict exists between reason and faith. Philosophy is based on reason, he declared, and theology comes from faith in divine revelation, yet both come from God. So Thomas believed that any differences between divine revelation and the conclusions of philosophy result from faulty reasoning. He also maintained that reason can support faith. Thomas accepted--on faith--the idea that God exists. However, he formulated five proofs of His existence to support such a belief.

According to Thomas, all people desire happiness, but they can satisfy this desire only through direct communion with God. He believed that God gives grace to help human beings overcome the influence of sin and achieve this communion. Thomas taught that the sacraments are important in communicating God's grace to people.

Thomas believed that governments have a moral responsibility to serve people and to help them lead virtuous lives. He declared that governments must not violate what he considered human rights--life, education, religion, and reproduction. Thomas also taught that--to be just--laws passed by human beings must not contradict divine law.

Bacon, Roger (1214-1292), was an English philosopher and scientist. He ranks as one of the leading figures in the development of science during the Middle Ages. Bacon became known as a founder of experimental science and one of the early researchers in the study of optics, the branch of physics that studies light. He helped lay the foundation for the revolution in science that occurred in Europe in the 1500's and 1600's.

His life. Bacon was born in the county of Somerset and studied liberal arts and philosophy at Oxford University. He left Oxford during the 1230's and began to teach at the University of Paris. About 1247, he gave up teaching because of ill health and returned to Oxford. He spent the next 10 years in the intensive study of mathematics, technology, and especially optics.

About 1257, Bacon joined the Franciscan religious order. He returned to Paris to urge educational reform within the church and to devote himself to discovering and spreading a system of all knowledge. At about this time, however, a dispute within the Franciscan order resulted in the introduction of censorship. Bacon's superiors allowed him to continue writing, but they prohibited him from publicizing his work.

At the request of Pope Clement IV, Bacon compiled a summary of his system of knowledge. He sent the summary, called the Opus maius (Longer Work), to the pope in 1267. It became Bacon's most significant work.

During the 1270's, Bacon wrote on astronomy, mathematics, and physics. In 1278, the church criticized some of his writings, and he was imprisoned in a Paris convent until 1292. Shortly before his death, Bacon finished his Compendium of Theological Studies. In it, he denounced what he considered the evils of the Christian world.

His work. Bacon's major achievements came in science, but he also wrote on philosophy and theology. These works show the influence of the Greek philosopher Aristotle, the Christian theologian Saint Augustine, and the Arab philosopher Avicenna.

In the Opus maius, Bacon urged the study of languages, especially Arabic, Greek, and Hebrew. He believed such study would enable scholars to improve their interpretation of the Bible and to discover more about Arabic and Greek scientific knowledge. Bacon considered mathematics the key to any scientific investigation, especially in astronomy.

Bacon demonstrated the usefulness and interdependence of mathematics and scientific experiments in optics, his primary field of study. He used the inductive method to study the formation of rainbows . Bacon also described the exact anatomy of the eye and the optic nerves.

Bonaventure, Saint (1221-1274), was an important medieval theologian and religious leader. In 1257, he became minister general of the Franciscan religious order. Bonaventure restored unity among disagreeing friars within the order. He supported the Franciscan ideal of poverty, but he also defended the possession of books and buildings for the pursuit of learning. Bonaventure believed the friars should study and teach in universities. He wrote many influential religious works and a biography of Saint Francis of Assisi, the Franciscans' founder.

He was known as the Seraphic Doctor. Though Italian (Tuscan) by birth, he studied philosophy and arts in Paris (1236-42). After he became a Franciscan in 1243, he studied theology under Alexander of Hales and taught at the University of Paris until Feb. 2, 1257, when he was elected minister general of his order. Although he was well acquainted with the philosophy of Aristotle, he feared its use in Christian theology and preferred the more traditional philosophy of Saint Augustine, often opposed to the Aristotelian synthesis of Saint Thomas Aquinas.

He successfully defended the rights of Mendicant orders to teach at the University of Paris, and he was mainly responsible for the Augustinian orientation of the Franciscans. He set forth his essentially Augustinian and mystical theory of Christian knowledge in his short Itinerary of the Mind into God (1259) and Retracing the Arts to Theology (1255-56). Created cardinal bishop of Albano by Gregory X on May 28, 1273, he played a prominent role at the Council of Lyons (1274), but resigned as minister general on account of illness.

Bonaventure was born in Bagnorea, near Viterbo, Italy. His family name was Fidanza. Bonaventure studied and taught at the University of Paris during the mid-1200's. Bonaventure was named cardinal bishop of Albano in 1273. He was canonized (declared a saint) in 1482 and named a Doctor of the Church in 1588. Bonaventure's feast day is July 15.

Grosseteste, Robert (1175-1253), was an English scholar, teacher, and bishop. He wrote many works on theology, optics, mathematics, and astronomy.

The first chancellor of the University of Oxford, he was appointed bishop of Lincoln in 1235. As bishop, he was a reformer and especially opposed the appointment of Italians to English ecclesiastical positions. His struggles to preserve the independence of the English church brought him into fierce conflict with both Henry III of England and Pope Innocent IV.

Grosseteste's commentaries on and translations of Aristotle influenced the development of scholasticism during the Middle Ages.

Thus he is sometimes called the founder of the modern scientific method. His scholarly reputation was such that his name was forged to at least 65 spurious works. Grosseteste combined the churchman’s active life with his scholarly pursuits. He deposed many abbots and priors for neglecting to provide adequate staff for the churches in their care, attended the First Council of Lyons (1245), and campaigned against the ecclesiastical corruption of the day.

He thought of light as the root of all knowledge and believed that understanding the laws controlling light would uncover all the laws of nature. His most famous pupil was Roger Bacon. As Bishop of Lincoln, Grosseteste was a zealous reformer and an able administrator. He defended the freedom of the Roman Catholic Church against royal interference. He was born in the county of Suffolk, and studied at Oxford.

For 50 years after his death he was venerated in his diocese as a saint. Some historians see in his outspoken criticism of ecclesiastical abuses a foreshadowing of the Reformation.

John Duns Scotus (1266–1308), Scottish theologian and philosopher, founder of a school of Scholasticism known as Scotism.

Born in Duns, Duns Scotus entered the Franciscan order and studied at the universities of Oxford and Paris. He later lectured at both universities on the Sentences, the basic theological textbook by the Italian theologian Peter Lombard. In 1303 he was exiled from Paris for refusing to support Philip IV, king of France, in his quarrel with Pope Boniface VIII over the taxation of church property. After a brief exile Duns Scotus returned to Paris, and he lectured there until 1307. Toward the end of that year he was sent to Cologne, where he lectured until his death on Nov. 8, 1308, in Cologne. His most important writings are two sets of Commentaries on the Sentences and the treatises Quodlibetic Questions, Questions on Metaphysics, and On the First Principle. Because of his intricate and skillful method of analysis, especially in his defense of the doctrine of the Immaculate Conception, he is known as Doctor Subtilis (Lat., "the Subtle Doctor").

In his system of philosophy Duns Scotus closely analyzed the concepts of causality and possibility in an attempt to set up a rigorous proof for the existence of God, the primary and infinite being. He held, however, that in order to know the truth in all its fullness and to fulfill one’s eternal destiny, a person must not only make use of the insights afforded by natural knowledge or philosophy but must also be taught by divine revelation. Revelation supplements and perfects natural knowledge, and, in consequence, no contradiction can exist between them.

For Duns Scotus, theology and philosophy were distinct and separate disciplines; they were, however, complementary, because theology uses philosophy as a tool. In his view, the primary concern of theology is God, considered from the standpoint of his own nature, whereas philosophy properly treats of God only insofar as he is the first cause of things. With regard to the nature of theology as a science, however, Duns Scotus departed sharply from his Dominican forerunner, Thomas Aquinas. Whereas Aquinas defined theology as primarily a speculative discipline, Duns Scotus saw theology as primarily a practical science, concerned with theoretical issues only insofar as they are ordered toward the goal of saving souls through revelation. He argued that through faith a person may know with absolute certainty that the human soul is incorruptible and immortal; reason plausibly may argue the existence of such qualities of the soul, but it cannot strictly prove that they exist.

Like Aquinas, Scotus was a realist in philosophy, but he differed from Aquinas on certain basic issues. A major point of difference concerned their views of perception. Duns Scotus held that a direct, intuitive grasp of particular things is obtained both through the intellect and the senses. Aquinas maintained that intellect did not directly know the singularity of material things but only the universal natures that are abstracted from sense perceptions.

Duns Scotus held that universals as such do not exist apart from the human mind, but that each separate or "singular" thing possesses a formally distinct nature that it shares in common with other things of the same kind. This fact, he taught, provides the objective basis of our knowledge of essential truths. Following the Franciscan tradition established by the Italian theologian St. Bonaventure, Duns Scotus stressed human freedom and the primacy of human will and acts of love over the intellect.

He avoided an arbitrary or voluntarist view of God’s acts, although he pointed out that the actual existence of things depends on a free decision made by God, and he argued that moral obligations depend on God’s will. That will, he taught, is absolutely free and not shaped or determined by particular motives. God commands an action not, as Aquinas asserts, because he sees it to be good; he makes it good by commanding it.

Duns Scotus was one of the most profound and subtle of the medieval theologians and philosophers known as Schoolmen. For many centuries after his death his followers, called Scotists, engaged in controversy with the adherents of Aquinas, who were called Thomists. In the 20th century the influence of Scotist philosophy was still strong within the church. Duns Scotus was a staunch supporter of the doctrine of the Immaculate Conception, which Pope Pius IX defined as a dogma of the Roman Catholic church in 1854.

William of Occam, or Ockham, (1285-1349), ranks among the most important philosopher-theologians of the Middle Ages; known as Doctor Invincibilis (Lat., "unconquerable doctor") and Venerabilis Inceptor (Lat., "worthy initiator"), English philosopher and Scholastic theologian, who is considered the greatest exponent of the nominalist school, the leading rival of the Thomist and Scotist schools.

After joining the Franciscans, Occam studied at Oxford, where he encountered the thought of John Duns Scotus and where, from about 1319 to 1320, he wrote a commentary on the Sentences of Peter Lombard. In 1324 he was called to the papal court at Avignon to answer a charge of heresy in a trial that dragged on without a formal conclusion. In 1328, Occam and Michael Cesena, the Franciscan minister-general, fled Avignon.

Although under a ban of excommunication, they were welcomed by the pope's enemy, Holy Roman Emperor Louis IV, to whom Occam is reputed to have said: "Defend me with your sword and I will defend you with my pen." At the Munich court of Louis, Occam wrote all his important political works, including those on papal power and the state. It is believed that he died in Munich, a victim of plague.

Occam has been called the greatest logician of the Middle Ages; using his logical faculty, he elaborated a theology that remained influential for centuries. In his Commentary on the Sentences and in other early works such as Quodlibeta septem (Seven Miscellaneous Questions) and Summa totius logicae (Sum of All Logic) Occam adopted a nominalist (see nominalism) solution to the problem of universals. He maintained that all existing things are individuals and that universality exists only in concepts or names. It followed that (1) God, unhampered by any universal essences, was free to create every individual unconnected with every other and (2) subsequent causal connections among such individuals were not necessary.

Occam accepted the Aristotelian dictum that science is demonstration based on certain, secure premises. He rejected the Thomistic view that theology is a proper science and therefore rejected rational demonstrations of God's existence, of divine attributes, and of the immortality of the soul.

Against the philosophical explanations of others, he used a principle sometimes called Occam's razor: "A plurality (of reasons) should not be posited without necessity". Ockham formulated the most radically nominalistic criticism of the Scholastic belief in intangible, invisible things such as forms, essences, and universals. He maintained that such abstract entities are merely second intentions of words, that is, references of words to other words rather than to actual things. His famous rule (also called ‘law of parsimony’), that one should not assume the existence of more things than are logically necessary, became a fundamental principle of modern science and philosophy.

In law and ethics, Occam's nominalist views led him to voluntarism and emphasis on the divine command. He concluded that the ultimate source of value and obligation lay not in any "natures" of things but in the free will of God. He regarded the rightness or wrongness of human acts as a function of their being commanded or forbidden by divine authority.

Bacon, Francis (1561-1626), was an English philosopher, essayist, jurist, and statesman. He was one of the earliest and most influential supporters of empirical (experimental) science and helped develop the scientific method of solving problems.

Bacon's principal philosophical writings are The Advancement of Learning (1605) and Novum Organum (New Instrument, 1620). These were the only books that he completed of a planned six-part project called Instauratio Magna (Great Renewal). He intended this work to be a survey of all learning to his time. Bacon wanted Great Renewal to lay a new foundation upon which the whole structure of all knowledge could be soundly built. He also wrote witty and original essays.

His life. Bacon was born in London, the son of an important councilor to Queen Elizabeth I. In 1584, he was elected to Parliament. Bacon held several government positions, notably lord chancellor. In 1621, Bacon was convicted of taking bribes and imprisoned briefly. Later evidence indicated he was not influenced by bribery. But he withdrew from public life and devoted the last five years of his life to study and writing.

His philosophy. Bacon believed all previous claims to knowledge, particularly of medieval science, were doubtful because they were based on poor logic. He believed the mind makes hasty generalizations, which prevent the attainment of knowledge. But he also believed that the mind could discover truths that would enable humanity to conquer disease, poverty, and war by gaining power over nature. To discover truths, the human mind must rid itself of four prejudices. Bacon called these prejudices Idols of the Mind.

The first Idol (of the Tribe) is the tendency of general human perception to generalize too quickly. Bacon claimed that uncritical perception cannot be trusted. The second Idol (of the Cave) is the tendency of people to base a knowledge of things on individual experiences, education, and tastes. People fail to realize how variable and untrustworthy these factors can be as a basis for claims to knowledge. The third Idol (of the Market Place) results from the dependence on language to communicate. Because words are often imprecise, they may be misinterpreted. The fourth Idol (of the Theater) is the influence of previous philosophies and laws of reasoning that are merely products of imagination.

Bacon believed the mind could attain truth if it followed the inductive method of investigation. He developed four steps of doing so: (1) listing all known cases in which a phenomenon occurs; (2) listing similar cases where the phenomenon does not occur; (3) listing the cases in which the phenomenon occurs in differing degrees; and (4) examination of the three lists. These steps would lead to the cause of a phenomenon.

Bacon suggested the use of preliminary hypotheses (assumptions) to aid scientific investigation. His treatment of hypothesis is still a subject of study. Bacon also wrote an unfinished romance called New Atlantis (published in 1627, after his death). The book describes an imaginary island where the inhabitants dedicate themselves to the study of science.

Descartes, Rene, (1596-1650), was a French philosopher, mathematician, and scientist. He is often called the father of modern philosophy. Descartes invented analytic geometry and developed a detailed account of the physical universe in terms of matter and motion. He was a pioneer in the attempt to formulate simple, universal laws of motion that govern all physical change.

Descartes wrote three major works. The first was Discourse on the Method of Rightly Conducting One's Reason, and Seeking Truth in the Sciences (1637), commonly known as the Discourse on Method. The others were Meditations on First Philosophy (1641), perhaps his most important work, and Principles of Philosophy (1644). His philosophy became known as Cartesianism.

His life. Descartes was born at La Haye, near Chatellerault, and was educated at a Jesuit college. He served in the armies of two countries and traveled widely. Money from an inheritance and from patrons enabled him to devote most of his life to study. From 1628 to 1649, Descartes led a quiet, scholarly life in the Netherlands and produced most of his philosophical writings. Late in 1649, he accepted an invitation from Queen Christina to visit Sweden. He became ill there and died in February 1650.

His philosophy. Descartes is called a dualist because he claimed that the world consists of two basic substances--matter and spirit. Matter is the physical universe, of which our bodies are a part. The human mind, or spirit, interacts with the body but can, in principle, exist without it.

Descartes believed that matter could be understood through certain simple concepts he borrowed from geometry, together with his laws of motion. In Descartes's view, the whole world--including its laws and even the truths of mathematics--was created by God, on whose power everything depends. Descartes thought of God as resembling the human mind in that both God and the mind think but have no physical being. But he believed God is unlike the mind in that God is infinite and does not depend for His existence on some other creator.

In Meditations on First Philosophy, Descartes first considered the strongest reasons that might be used to show that he could never be certain of anything. These so-called "skeptical" arguments included the idea that perhaps he might be dreaming, so that nothing he seemed to perceive would be real. In another argument, Descartes reflected that perhaps God or some evil spirit was constantly tricking his mind, causing him to believe what was false. Descartes then responded to these arguments. He began with the observation that even if he were dreaming, or constantly deceived, he could at least be certain that he had thoughts, and therefore existed as a thinking being. This, he wrote, was a "clear and distinct" perception of the mind. Nothing could make him doubt it. In another work, Descartes introduced the famous Latin phrase cogito ergo sum, which means I think, therefore I am.

Descartes then argued that he could also clearly and distinctly perceive that an infinitely powerful and good God exists. This God would not allow Descartes to be deceived in his clearest perceptions. Through this conception of God, Descartes sought to establish that the physical world exists with the properties the philosopher assumed in his physics. He continued to hold, however, that sensory appearances are often misleading.

Spinoza, Baruch, (1632-1677), was a Dutch philosopher. He was also called Benedict, the Latin form of Baruch.

Spinoza was born in Amsterdam of Jewish parents. He early acquired the reputation of a freethinker and was excommunicated by the Jewish community in 1656. He then lived in several towns in the Netherlands, earning a living as a lens grinder. Throughout his career, Spinoza was a strong supporter of religious and political liberalism. He prized his independence, rejecting offers of a pension from King Louis XIV of France and of a university professorship in Germany. Although he was respected by many, Spinoza was controversial because of his unorthodox views on religion, philosophy, and politics.

Spinoza's philosophy was strongly influenced by the French philosopher Rene Descartes. Spinoza accepted Descartes's view that thought and matter are the basic categories of reality. The physical world is nothing but bits of matter moving and interacting according to general causal laws. However, in his masterpiece, The Ethics (published shortly after his death), Spinoza developed Descartes's ideas in radically unconventional ways. Spinoza stated that "God or Nature" is the only substance. Thought and matter are God's infinite attributes, and all finite things (such as human minds and bodies) are only modes or states of the attributes of God. Spinoza allowed no exceptions to causality, denying free will to humanity and God. He maintained, however, that freedom of mind can be obtained by rational understanding of our place in nature and our subjection to its laws--particularly the laws of the passions.

Leibniz, Gottfried Wilhelm, (1646-1716), was a German philosopher, mathematician, and scholar. He and Sir Isaac Newton independently developed the theory of the differential and integral calculus . Leibniz also developed the binary numeration system and invented a calculating machine. He believed the truths of arithmetic could be derived from purely logical principles.

Leibniz developed a complex philosophical system. He believed that the ultimate elements of reality are indivisible, mindlike substances called monads. He identified the changing states of monads as "perceptions". But Leibniz thought only those monads that are true minds--divine, angelic, human, or animal--could perceive consciously. Leibniz said monads are "windowless"--that is, their states are generated from within the monad itself rather than being caused from without.

Although monads do not interact causally with each other, Leibniz believed that God created the world in such a way that the perceptions of any monad are "harmonized" with all others. In this and other ways, the world that God has chosen to create is the "best of all possible worlds." God can conceive of other worlds that would be better than this world in some ways. However, such other worlds would necessarily be worse in other ways. Material objects are not ultimate realities. They are only "appearances" arising from the perceptions of monads.

Leibniz was born in Leipzig. He traveled extensively in Europe on various diplomatic missions for German rulers. He died in Hanover, where he spent much of his later life.

Newton, Sir Isaac (1642-1727), an English scientist, astronomer, and mathematician, invented a new kind of mathematics, discovered the secrets of light and color, and showed how the universe is held together. He is sometimes described as "one of the greatest names in the history of human thought" because of his great contributions to mathematics, physics, and astronomy.

Newton discovered how the universe is held together through his theory of gravitation. He discovered the secrets of light and color. He invented a branch of mathematics, calculus, also invented independently by Gottfried Leibniz, a German mathematician . Newton made these three discoveries within 18 months from 1665 to 1667.

The theories of motion and gravitation. Newton said the concept of a universal force came to him while he was alone in the country. He had been forced to flee there because of the outbreak of plague in the city of Cambridge. During this time, Newton suddenly realized that one and the same force pulls an object to earth and keeps the moon in its orbit. He found that the force of universal gravitation makes every pair of bodies in the universe attract each other. The force depends on (1) the amount of matter in the bodies being attracted and (2) the distance between the bodies. The force by which the earth attracts or pulls a large rock is greater than the pull on a small pebble because the rock contains more matter. The earth's pull is called the weight of the body. With this theory, Newton explained why a rock weighs more than a pebble.

He also proved that many types of motion are due to one kind of force. He showed that the gravitational force of the sun keeps the planets in their orbits, just as the gravitational force of the earth attracts the moon. The falling of objects on earth seems different from the motion of the moon because the objects fall straight down to the earth, while the moon moves approximately in a circle around the earth. Newton showed that the moon falls just like an object on earth. If the moon did not fall constantly toward the earth, it would move in a straight line and fly off at a tangent to its orbit. Newton calculated how much the moon falls in each second and found the distance is 1/3600 of the distance an object on earth falls in a second. The moon is 60 times as far from the earth's center as such an object. Consequently, the force of the earth on an object 60 times as far away as another object is 1/3600.

The Principia. Newton concluded his first investigations on gravity and motion in 1665 and 1666. Nothing was heard of them for nearly 20 years. His original theory had been based on an inaccurate measurement of the earth's radius, and Newton realized differences between the theory and the facts. Although he later learned the true value of the earth's size, he was not led to complete his investigation or to produce a book for publication.

One day in 1684, Edmond Halley, an English astronomer, Robert Hooke, an English scientist, and Christopher Wren, the architect, were discussing what law of force produced the visible motion of the planets around the sun. They could not solve this problem. Halley went to Cambridge to ask Newton about it. He found Newton in possession of complete proof of the law of gravity. Halley persuaded Newton to publish his findings. Halley paid all the expenses, corrected the proofs, and laid aside his own work to publish Newton's discoveries. Newton's discoveries on the laws of motion and theories of gravitation were published in 1687 in Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy). This work, usually called Principia or Principia Mathematica, is considered one of the greatest single contributions in the history of science. It includes Newton's laws of motion and theory of gravitation. It was the first book to contain a unified system of scientific principles explaining what happens on earth and in the heavens.

Light and color. Newton's discoveries in optics were equally spectacular. He published the results of his experiments and studies in Opticks (1704).

Newton's discoveries explained why bodies appear to be colored. The discoveries also laid the foundation for the science of spectrum analysis. This science allows us to determine the chemical composition, temperature, and even the speed of such hot, glowing bodies as a distant star or an object heated in a laboratory.

Newton discovered that sunlight is a mixture of light of all colors. He passed a beam of sunlight through a glass prism and studied the colors that were produced. A green sweater illuminated by sunlight looks green because it largely reflects the green light in the sun and absorbs most of the other colors. If the green sweater were lighted by a red light or any color light not containing green, it would not appear green.

The study of light led Newton to consider constructing a new type of telescope in which a reflecting mirror was used instead of a combination of lenses. Newton's first reflecting telescope was 6 inches (15 centimeters)long, and, through it, Newton saw the satellites of Jupiter.

Early life. Newton was born at Woolsthorpe, Lincolnshire, on Dec. 25, 1642. He attended Grantham grammar school. As a boy, he was more interested in making mechanical devices than in studying. His youthful inventions included a small windmill that could grind wheat and corn, a water clock run by the force of dropping water, and a sundial. He left school when he was 14 to help his widowed mother manage her farm. But he spent so much time reading, he was sent back to school.

He entered Trinity College, Cambridge University, in 1661. He showed no exceptional ability during his college career and graduated in 1665 without any particular distinction. He returned to Cambridge as a fellow of Trinity College in 1667.

Newton became professor of mathematics at Cambridge in 1669. He lectured once a week on arithmetic, astronomy, geometry, optics, or other mathematical subjects. He was elected to the Royal Society in 1672.

Public life. Newton became active in public life after the publication of Principia. He became the Cambridge University member of Parliament in 1689 and held his seat until Parliament dissolved the following year. He became warden of the mint in 1696. He was appointed master of the mint in 1699, a position he held until his death.

In 1699, he also became a member of the Royal Society council and an associate of the French Academy. He was elected to Parliament again from the university in 1701. He left Cambridge and settled permanently in London in 1701. He became president of the Royal Society in 1703 and was reelected annually until his death. Queen Anne knighted Newton in 1705. He died in 1727 and was buried in Westminster Abbey.

Personal characteristics. Newton did not enjoy the scientific arguments that arose from his discoveries. Many new scientific theories are opposed violently when they are first announced, and Newton's did not escape criticism. He was so sensitive to such criticism that his friends had to plead with him to publish his most valuable discoveries.

Newton was a bachelor who spent only part of his time studying mathematics, physics, and astronomy. He was also a student of alchemy and made many alchemical experiments. He also spent a great deal of his time on questions of theology and Biblical chronology.

As a professor, he was very absent-minded. He showed great generosity to his nephews and nieces and to publishers and scientists who helped him in his work.

He was modest in his character. He said of himself shortly before his death, "I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me".

Albert Einstein, the German-born American physicist, rejected Newton's explanation of universal gravitation but not the fact of its operation. He said that his own work would have been impossible without Newton's discoveries. He also said that the concepts Newton developed "are even today still guiding our thinking in physics."

Locke, John (1632-1704), was an English philosopher. His writings have influenced political science and philosophy. Locke's book Two Treatises of Government (1690) strongly influenced Thomas Jefferson in the writing of the Declaration of Independence.

His life. Locke was born in Wrington in Somerset County. He attended Oxford University. In 1666, he met Anthony Ashley Cooper, who later became the first Earl of Shaftesbury. The two men became close friends. In 1679, the earl became involved in plots against the king, and suspicion also fell on Locke. The philosopher decided to leave England. In 1683, he moved to the Netherlands, where he met Prince William and Princess Mary of Orange. William and Mary became the rulers of England in 1689, and Locke returned to England as a court favorite. Until his death, he wrote widely on such subjects as educational reform, freedom of the press, and religious tolerance.

His philosophy. Locke's major work was An Essay Concerning Human Understanding (1690). It describes his theory of how the mind functions in learning about the world. Locke argued against the doctrine of innate ideas, which stated that ideas were part of the mind at birth and not learned or acquired later from outside sources. Locke claimed that all ideas were placed in the mind by experience. He declared that there were two kinds of experience, outer and inner. Outer experience was acquired through the senses of sight, taste, hearing, smell, and touch, which provide information about the external world. Inner experience was acquired by thinking about the mental processes involved in sifting these data, which furnished information about the mind.

Locke believed that the universe contained three kinds of things--minds, various types of bodies, and God. Bodies had two kinds of properties. One kind was mathematically measurable, such as length and weight, and existed in the bodies themselves. The second kind was qualitative, such as sound and color. These properties were not in the bodies themselves but were simply powers that bodies had to produce ideas of colors and sounds in the mind.

According to Locke, a good life was a life of pleasure. Pleasure and pain were simple ideas that accompanied nearly all human experiences. Ethical action involved determining which act in a given situation would produce the greatest pleasure--and then performing that act. Locke also believed that God had established divine law. This law could be discovered by reason, and to disobey it was morally wrong. Locke thought that divine law and the pleasure principle were compatible.

Locke believed that people by nature had certain rights and duties. These rights included liberty, life, and ownership of property. By liberty, Locke meant political equality. The task of any state was to protect people's rights. States inconvenience people in various ways. Therefore, the justification for a state's existence had to be found in its ability to protect human rights better than individuals could on their own. Locke declared that if a government did not adequately protect the rights of its citizens, they had the right to find other rulers.

Berkeley, George (1685-1753), was an Anglican bishop and philosopher. He tried to reconcile the science of his day with Christianity.

Berkeley argued that physical things, such as tables and trees, consist entirely of the ideas or sensations we have of them. In his view, an apple is nothing but its color, shape, texture, weight, taste, and other qualities, all of which we experience through our senses. He argued that the qualities or ideas that we experience exist only in our minds. They change as the person perceiving them changes. For example, the same lukewarm water seems warm to a cold hand and cool to a warm hand. Thus, it seemed to Berkeley, the qualities we perceive are really ideas that depend upon the mind perceiving them and have no independent existence.

Other philosophers had believed that a physical thing also consists of matter. Matter is the stuff in which the various qualities are supposed to exist. Matter supposedly exists outside of and independent of the mind. But because we never have any direct experience of matter, Berkeley claimed that we have no good reason to think it exists.

If, as Berkeley argued, the entire physical world consists only of ideas, then the world exists only in the minds that perceive it. However, because we believe that physical things continue to exist when we are not observing them, we must assume that there exists a mind that observes all physical things all the time. It is only the constant observation by such a mind that keeps things in existence when we are not observing them. This universally present and observant mind is God.

Because Berkeley believed that things are entirely composed of ideas, he is a representative of philosophical idealism. Because his view of the world is restricted to what we learn in our direct experience of it, he also represents philosophical empiricism. Berkeley was born in County Kilkenny, Ireland.

Hume, David (1711-1776), a Scottish philosopher, was one of the most important figures in the history of philosophy. His thought marks the culmination of the British philosophical movement of the 1700's known as empiricism. The empiricists tried to show that all human thought and knowledge is based on the direct experience of the world through the senses. In order to show this, Hume and the other empiricists had to analyze the workings of the human mind.

Hume's thought. Hume distinguished between impressions and ideas. Impressions are made on the mind when we directly experience anything. Ideas do not arise directly from experience, but are formed from previous impressions. For example, one's idea of a table or of a triangle is based on previous impressions and experiences of those things. We can form ideas of things we have never experienced, but only by combining previous experiences in new ways.

Hume applied this theory to philosophical questions, especially questions about the limits of knowledge. He maintained that since ideas must be based on experience, ideas without such basis lack a proper foundation. Hume argued that a number of ideas central to traditional philosophy are problematic in this way. These include the ideas of substance, the self, and causality.

The idea of substance is the idea of the stuff or matter of a thing, as opposed to its qualities. These qualities (for example, color, shape, smell, or taste) are considered to be qualities of something--that is, of the substance or matter. But we can experience only the qualities, and we never can experience the substance itself. Thus, the idea of substance has no meaning.

The idea of the self is the idea of something in a person that remains identical through time. I have the idea that I remain the same person despite the changes that occur in me. But, since I cannot locate in myself an element that is always present and never changes, the idea of such a self has no basis in experience.

The idea of causality is the idea that two events are connected in such a way that one causes the other. For example, it seems that one billiard ball rolling into another causes the second ball to move. Hume pointed out that, in such cases, we perceive only that events like the cause are regularly followed by events like the effect. The rolling of one ball into another is regularly followed by the second ball starting to move. But we never observe anything that actually connects the two events. But causes are supposed to connect events. Thus, the idea of causality, like the ideas of substance and self, has no basis in experience.

Hume argued that there are only two kinds of things about which we can know anything: matters of fact and relations of ideas. Statements about matters of fact are really descriptions of our experience of the world and ourselves. Statements about relations of ideas concern the truths of logic and mathematics and the definitions of words and ideas. They are supposedly discoverable by the operations of reason alone without reliance on sense experience. For example, we need not take a survey of bachelors to know that bachelors must be unmarried and male. This truth is discoverable solely on examination of the ideas involved. According to Hume, any statement is worthless that neither makes clear the meanings of ideas nor tells us anything about experience. Hume believed there were many such statements in traditional philosophy and theology. His aim was to expose long-accepted but unsound ideas.

In ethics, Hume argued that it is impossible to conclude from how things and people are anything about how they should be. He also believed that our basic choices are determined, not by reason, but by desires and passions that use reason as a tool to attain their goals. In religion, Hume criticized the argument that the world resembles a large and complex artifact--that is, something made by design and intention. Thus, it seems natural to conclude that it must have been made by a being capable of such a grand achievement, who could only be God. But Hume objected that it could have come into existence without any conscious plan or effort on the part of a God.

Hume's life. Hume was born and educated in Edinburgh. His first major work was A Treatise of Human Nature (1739). His other works include An Enquiry concerning Human Understanding (1748), An Enquiry concerning the Principles of Morals (1751), Dialogues concerning Natural Religion (1779), an influential history of Great Britain, and many essays.

Rousseau, Jean-Jacques (1712-1778), was a French philosopher. He was the most important writer of the Age of Reason, a period of European history that extended from the late 1600's to the late 1700's. Rousseau's philosophy helped shape the political events that led to the French Revolution. His works have influenced education, literature, and politics.

Early life. Rousseau was born in Geneva, in what is now Switzerland. The Rousseau family was of French Protestant origin and had been living in Geneva for nearly 200 years. Rousseau's mother died as a result of giving birth to him, leaving the infant to be raised by his quarrelsome father. As the result of a fight in 1722, Rousseau's father was forced to flee Geneva. The boy's uncle then took responsibility for his upbringing.

In 1728, Rousseau ran away from Geneva and began a life of wandering, trying and failing at many jobs. He was continually attracted to music. For years, Rousseau was undecided between careers in literature or music.

Shortly after leaving Geneva, at the age of 15, Rousseau met Louise de Warens, a well-to-do widow. Under her influence, Rousseau joined the Roman Catholic Church. Although he was 12 or 13 years younger than Madame de Warens, Rousseau settled down with her near Chambery in the Duchy of Savoy. He described the happiness of their relationship in his famous autobiography, Confessions (written 1765 or 1766-1770, published in 1782, 1788). However, the relationship did not last and Rousseau eventually left in 1740.

In 1741 or 1742, Rousseau was in Paris seeking fame and fortune and hoping to establish himself in a musical career. His hope lay in a new system of musical notation that he had invented. He presented the project to the Academy of Sciences, but it aroused little interest.

In Paris, Rousseau became friends with the philosophes, a group of famous writers and philosophers of the time. He gained the patronage of well-known financiers. Through their sponsorship, he served in Venice as secretary to the French ambassador in 1743 and 1744.

The turning point in Rousseau's life came in 1749, when he read about a contest sponsored by the Academy of Dijon. The academy was offering a prize for the best essay on the question: Whether the revival of activity in the sciences and arts was contributing to moral purification. As he read about the contest, Rousseau realized the course his life would take. He would oppose the existing social structure, spending the rest of his life indicating new directions for social development. Rousseau submitted an essay to the academy. His "Discourse on the Sciences and the Arts" (1750 or 1751) attacked the arts and sciences for corrupting humanity. He won the prize and the fame he had so long desired.

Later life. When Rousseau converted to Catholicism, he lost his citizenship in Geneva. To regain his citizenship, he reconverted to Protestantism in 1754. In 1757, he quarreled with the philosophes, feeling they were persecuting him. Rousseau's last works are marked by emotional distress and guilt. They reflect his attempt to overcome a deep sense of inadequacy and to find an identity in a world that seemed to have rejected him.

In three Dialogues, also called Rousseau, Judge of Jean-Jacques (written 1772-1776, published 1782), Rousseau tried to answer charges by his critics and those he believed were persecuting him. His final work was the beautiful and serene Reveries of the Solitary Stroller (written 1776-1778, published 1782). Rousseau also wrote poetry and plays in both verse and prose. His musical works include many essays on music, an influential opera called The Village Soothsayer (1752), a highly respected Dictionary of Music (1767), and a collection of folk songs entitled The Consolation of My Life's Miseries (1781). In addition, he wrote on botany, an interest he cherished, especially during the last years of his life.

His ideas. Rousseau criticized society in several essays. For example, in "Discourse on the Origin and Foundations of Inequality" (1755), he attacked society and private property as causes of inequality and oppression. The New Heloise (1761) is both a romantic novel and a work that strongly criticizes the false codes of morality Rousseau saw in society. In The Social Contract (1762), a landmark in the history of political science, Rousseau gave his views concerning government and the rights of citizens. In the novel Emile (1762), Rousseau stated that children should be taught with patience and understanding. Rousseau recommended that the teacher appeal to the child's interests, and discouraged strict discipline and tiresome lessons. However, he also felt that children's thoughts and behavior should be controlled.

Rousseau believed that people are not social beings by nature. He stated that people, living in a natural condition, isolated and without language, are kind and without motive or impulse to hurt one another. However, once they live together in society, people become evil. Society corrupts individuals by bringing out their inclination toward aggression and selfishness.

Rousseau did not advise people to return to a natural condition. He thought that people could come closest to the advantages of that condition in a simple agricultural society in which desires could be limited, sexual and egotistical drives controlled, and energies directed toward community life. In his writings, he outlined institutions he believed were necessary to establish a democracy in which all citizens would participate.

Rousseau believed that laws should express the general will of the people. Any kind of government could be considered legitimate, provided that social organization was by common consent. According to Rousseau, all forms of government would eventually tend to decline. The degeneration could be restrained only through the control of moral standards and the elimination of special interest groups. Robespierre and other leaders of the French Revolution were influenced by Rousseau's ideas on the state. Also, many Socialists and some Communists have found inspiration in Rousseau's ideas.

His literary influence. Rousseau foreshadowed Romanticism, a movement that dominated the arts from the late 1700's to the mid-1800's. In both his writings and his personal life, Rousseau exemplified the spirit of Romanticism by valuing feeling more than reason, impulse and spontaneity more than self-discipline. Rousseau introduced true and passionate love to the French novel, popularized descriptions of nature, and created a lyrical and eloquent prose style. His Confessions created a fashion for intimate autobiographies.

Voltaire, (1694-1778), was the pen name of Francois Marie Arouet, a French author and philosopher. Voltaire's clear style, sparkling wit, keen intelligence, and strong sense of justice made him one of France's most famous writers.

Candide (1759), Voltaire's best-known work, is a brilliant philosophical tale that has been translated into more than 100 languages. On the surface, the work describes the adventures of an inexperienced young man as he wanders around the world. Philosophically, Candide is recognized as a complex inquiry into the nature of good and evil.

Voltaire, the son of a lawyer, was born in Paris. He received an excellent education at a Jesuit school. He showed little inclination to study law, and his schooling ended at the age of 16. He soon joined a group of sophisticated aristocrats who had little reverence for anything except wit, pleasure, and literary talent. Paris society sought Voltaire's company because of his cleverness, his remarkable ability to write verses, and his gift for making people laugh.

There are several theories about the origin of Voltaire's pen name, which he adopted in 1718. The most widely accepted one is that Voltaire comes from an imperfect arrangement of the letters making up the French equivalent of Arouet the Younger.

Imprisonment and early success. In 1717, Voltaire was imprisoned in the Bastille for satirical verses that he may or may not have written ridiculing the government. During his 11 months in prison, he finished his tragedy Oedipe. The success of the play in 1718 made Voltaire the greatest French playwright of his time. He maintained this reputation--with more than 50 plays--for the rest of his life. While in prison, Voltaire also worked on La Henriade, an epic poem about King Henry IV. This poem, written in the style of the Aeneid by the Roman poet Virgil, was published in 1723.

Voltaire became independently wealthy in his early 30's through an inheritance and wise investments. He was also a celebrity who had three plays performed in 1725 to help celebrate the wedding of King Louis XV. Royal pensions and other honors followed. But all this success ended abruptly in 1726 when the Chevalier de Rohan, a powerful young nobleman, scornfully asked: "What is your name anyway? Monsieur de Voltaire or Monsieur Arouet?" His question implied that Voltaire was claiming to be a nobleman while he was in fact of common origin. Voltaire supposedly replied that whatever his name was, he was bringing it honor, which was more than Rohan could say for himself. This answer cost Voltaire a beating by Rohan's men. Challenged to a duel by Voltaire, Rohan had him thrown into the Bastille again. A few days later, Voltaire was allowed to choose between continued imprisonment and exile.

Exile and return to France. Voltaire chose exile. From 1726 to 1729, he lived in England, for him a land of political and religious freedom. There, he met the writers Alexander Pope and Jonathan Swift and was attracted to the ideas of the philosopher John Locke and the scientist Sir Isaac Newton. It has been said that Voltaire went into exile a poet and came back a philosopher.

Voltaire returned to France in 1729, and published several works. The most important ones were History of Charles XII (1731) and his best-known play, Zaire (1732). In 1733, his Letters Concerning the English Nation appeared in England. This book appeared in France the next year in an unauthorized edition called Philosophical Letters. Voltaire's praise of English customs, institutions, and style of thought was an indirect criticism of their French counterparts. French authorities condemned the book, and Voltaire fled from Paris.

Voltaire found a home with the Marquise du Chatelet, one of the most cultured and intelligent women of the day. From 1734 to 1749, he lived in her chateau at Cirey in Lorraine. During this period, he wrote several plays, an essay on metaphysics, two works on Sir Isaac Newton, and some poetry. He also wrote two notable philosophical tales. One of them, Zadig (1747), explores the problem of human destiny. The other, Micromegas, was started at Cirey and was published in 1752. In it, Voltaire used giant visitors from a distant star and from the planet Saturn to discuss the relative insignificance of human pretensions in answering religious questions. In this work, Voltaire also encouraged the use of human reason for the development of science.

Later years. Following Mme. du Chatelet's death in 1749, Voltaire accepted the invitation of Frederick the Great to settle in Berlin. After three years of living under the social and intellectual tyranny of the "Philosopher King," as Voltaire called him, Voltaire settled in Switzerland. He lived near Geneva in a chateau that he named Les Delices (The Delights). It is now the Voltaire Institute and Museum. A severe earthquake in Portugal in 1755 inspired Voltaire to write an important philosophical poem, The Lisbon Disaster. This work was published with his Poem on Natural Law in 1756.

In 1759, Voltaire purchased an estate called Ferney on the French-Swiss border. He lived there until just before his death. In an effort to correct the wrongs he saw in the world, Voltaire produced a constant flow of books, plays, pamphlets, and letters. Ferney soon became the intellectual capital of Europe. There Voltaire wrote Candide, added to his Philosophical Dictionary, and completed his Universal History, also called Essay on the Manners and Spirit of Nations (1759-1766). He fought religious intolerance and aided victims of religious persecution. His rallying cry was "ecrasez l'infame" ("Crush the evil thing"), referring to religious superstition.

Voltaire returned to Paris at the age of 83 and was enthusiastically received. There he saw his last play, Irene (1778), warmly applauded. But the excitement of the trip was too much for him, and he died in Paris.

The Roman Catholic Church, because of much criticism by Voltaire, refused to allow him to be buried in church ground. However, his body was finally taken to an abbey in Champagne. In 1791, Voltaire's remains were transferred to the Pantheon in Paris, where many of France's greatest are buried.

Diderot, Denis, (1713-1784), was a major French philosopher of an intellectual movement called the Age of Reason. His work included fiction, drama, art and literary criticism, and satire. Diderot was also a brilliant conversationalist. He spent much of his life compiling, editing, and writing the French Encyclopedia, a reference work that reflected revolutionary political views and antireligious sentiment. Diderot's major philosophical works are Thoughts on the Interpretation of Nature (1754) and d'Alembert's Dream (1769). Today, Diderot is increasingly appreciated for his major literary writings, especially the novels The Nun (1760) and Jacques the Fatalist (1773) and the satirical dialogue Rameau's Nephew (written 1762-1764).

Diderot strongly supported experimental methods in philosophy and science. He believed that nature was in a state of constant change and no permanently adequate interpretation of it was possible. Diderot was also a philosophical materialist, believing that thought developed from the movements and changes of matter. His views on this subject were vague, as were his religious opinions. At one time, he was an atheist. At another time, Diderot was a deist, believing that God existed independently of the world and had no interest in it. But he later suggested that all of nature was God. Diderot was born in Langres, near Chaumont.

Kant, Immanuel (1724-1804), was an important German philosopher. His work was influential because he established the main lines for philosophical developments since his day.

In his chief work, Critique of Pure Reason (1781), Kant discussed the nature and limits of human knowledge. This question became important to him because of Scottish philosopher David Hume's theories. Before Hume, most philosophers assumed that our past experience could provide knowledge about matters that go beyond our experience. But Hume argued that we cannot be certain of anything beyond our experience. For example, the law of universal gravitation states that a force of attraction acts between all objects. But our experience is restricted to only a few objects that we have observed. We cannot be certain that the force operates on objects beyond our experience .

Kant's ideas. Kant believed that we cannot justify claims beyond our actual experience as long as we continue to think of the mind and its objects as separate things. He held instead that the mind is actively involved in the objects it experiences. That is, it organizes experience into categories, or forms of understanding. All things capable of being experienced are also arranged in these categories. Kant believed that we can have knowledge of what we have not yet experienced as well as what we have already experienced. But he limited this knowledge to possible experience.

Kant's conclusions meant having to abandon any claim to know things as they are in themselves, things in which the mind is not involved. But he did not deny the existence of things in themselves, which he called noumena. Some philosophers regarded this refusal to claim absolute knowledge as too serious a limitation on a system of philosophy. Other philosophers argued that we have an intuitive, nonrational knowledge of things.

Kant also wrote on theology and ethics. He argued that the existence of God cannot be proved or disproved by the use of reason. According to Kant, reason is restricted to ideas of possible experience, and the idea of God transcends all possible experience. Yet Kant held that faith could be rational because we cannot think of the world as orderly or justify our morality without supposing the existence of God.

In ethics, Kant tried to show (1) that doing one's duty consisted in following only those principles that one would accept as applying equally to all, and (2) that even assuming that scientists can predict what we are going to do, the predictions do not conflict with our use of free will. Therefore, the predictions of scientists have no bearing on our duty to live morally. Kant's chief work on ethics is the Critique of Practical Reason (1788).

His life. Kant was born and lived in Konigsberg, in East Prussia (now Kaliningrad in Russia). He taught near Konigsberg from 1746 to 1755, and then at Konigsberg University until his death nearly 50 years later.

Hegel, G. W. F. (1770-1831), was one of the most influential German philosophers. Hegel argued that in order to understand any aspect of human culture, we must retrace and understand its history.

Hegel's emphasis on the importance of historical understanding has greatly promoted the development of the historical study of philosophy, art, religion, science, and politics. The historical approach to human culture inspired by Hegel eventually spread far beyond the borders of Germany.

Hegel's dialectic. Hegel developed a theory of history that became known as his dialectic. Hegel believed that all historical developments have three basic characteristics. First, they follow a course that is necessary--that is, they could not have happened in any other way. To understand a historical development in any area of human thought or activity, we must see why it necessarily happened as it did. Second, each historical development represents not only change but progress. Third, Hegel argued that one phase of any historical development tends to be confronted and replaced by its opposite. This opposite, in turn, tends to be replaced by a phase that is somehow a resolution of the two opposed phases. These three phases of a typical dialectical development have often been called thesis, antithesis, and synthesis. But Hegel did not use those terms.

Hegel applied his dialectic to all areas of human life. For example, he argued that the attempt to achieve satisfaction through the external pursuit of power and property tends to be rejected in favor of the attempt to achieve an inner state of harmony and tranquility. This opposition between external activity and an inner nonactive state of mind can be resolved by having one's external activity emerge from a harmonious inner state.

Hegel also argued, in a political example, that a period marked by the concentration of political power in one person tends to be followed by a period of widely distributed power. This opposition might be resolved by a period in which there is both some distribution and some concentration of power. Thus, an absolute monarchy might be replaced by an absolute democracy and, in turn, by a representative form of government.

Hegel's writings. In most of his writings, Hegel tried to demonstrate the presence of dialectical developments. In his first published book, Phenomenology of Spirit (1807), he dealt with the development of "forms of consciousness." These forms of consciousness include a rich and bewildering variety of states of mind, views of the world, ethical positions, religious outlooks, types of physical activity, and forms of social organization. Hegel tried to demonstrate how they progressed in what he claimed was a necessary and historical sequence that moved through contradiction and resolution to ever greater levels of maturity.

In his second book, Science of Logic (1812-1816), Hegel tried to show the same sort of dialectic in the development of philosophical theories about reality. His Encyclopedia of the Philosophical Sciences (1817) contains his philosophic system in a condensed form. It has three sections: a shorter version of his book on logic, a "Philosophy of Nature," and a "Philosophy of Spirit." His last book, Philosophy of Right (1821), analyzes the dialectical development of social, ethical, and legal systems. After Hegel's death, his students published his lectures on the philosophy of history, religion, and art and on the history of philosophy. They reconstructed the lectures mainly from their notes.

Life. Georg Wilhelm Friedrich Hegel was born in Stuttgart. He attended the University of Tubingen, near Stuttgart. His university teaching career began in 1801 in Jena. He was professor of philosophy at the University of Berlin from 1818 until his death.

Marx, Karl (1818-1883), was a German philosopher, social scientist, and professional revolutionary. Few writers have had such a great and lasting influence on the world. Marx was the chief founder of two of the most powerful mass movements in history--democratic socialism and revolutionary communism.

Marx was sometimes ignored or misunderstood, even by his followers. Yet many of the social sciences--especially sociology--have been influenced by his theories. Many important social scientists of the late 1800's and the 1900's can be fully understood only by realizing how much they were reacting to Marx's beliefs.

The life of Marx

Karl Heinrich Marx was born and raised in Trier, in what was then Prussia. His father was a lawyer. Marx showed intellectual promise in school and went to the University of Bonn in 1835 to study law. The next year, he transferred to the University of Berlin. There he became much more interested in philosophy, a highly political subject in Prussia, where citizens were not permitted to participate directly in public affairs. Marx joined a group of radical leftist students and professors whose philosophic views implied strong criticism of the severe way in which Prussia was governed.

In 1841, Marx obtained his doctorate in philosophy from the university in Jena. He tried to get a teaching position but failed because of his opposition to the Prussian government. He became a free-lance journalist and helped create and manage several radical journals. After his marriage in 1843, he and his wife moved to Paris. There they met Friedrich Engels, a young German radical, who became Marx's best friend and worked with him on several articles and books. Marx lived in Brussels, Belgium, from 1845 to 1848, when he returned to Germany. He edited the Neue Rheinische Zeitung, which was published in Cologne during the German revolution of 1848. This journal made Marx known throughout Germany as a spokesman for radical democratic reform. After the collapse of the 1848 revolution, Marx fled from Prussia. He spent the rest of his life as a political exile in London.

Marx led a hand-to-mouth existence because he was too proud--or too much a professional revolutionary--to work for a living. He did write some articles for newspapers. His most regular job of this kind was that of political reporter for the New York Tribune. But generally, Marx, his wife, and their six children survived only because Engels sent them money. In 1864, Marx founded The International Workingmen's Association, an organization dedicated to improving the life of the working classes and preparing for a socialist revolution.

Marx suffered from frequent illnesses, many of which may have been psychological. Even when physically healthy, he suffered from long periods of apathy and depression and could not work. Marx was learned and sophisticated, but he was often opinionated and arrogant. He had many admirers but few friends. Except for Engels, he lost most of his friends--and many of them became his enemies.

Marx's writings

Most of Marx's writings have been preserved. They include not only his books, but also most of his correspondence and the notes of his speeches.

Philosophic essays. Some of Marx's philosophic essays were published during his lifetime, but others were not discovered until the 1900's. Marx wrote some of them alone and some with Engels. The essays range from one of about 15 sentences to a 700-page book, The German Ideology (1845-1846), written with Engels.

Marx wrote his essays between 1842 and 1847. They spell out the philosophic foundations of his radicalism. The chief themes in the essays include Marx's bitter view that economic forces were increasingly oppressing human beings and his belief that political action is a necessary part of philosophy. The essays also show the influence of the philosophy of history developed by the German philosopher Georg Wilhelm Friedrich Hegel.

The Communist Manifesto was a pamphlet written jointly with Engels on the eve of the German revolution of 1848. Its full title is the Manifesto of the Communist Party. The manifesto is a brief but forceful presentation of the authors' political and historical theories. It is the only work they produced that can be considered a systematic statement of the theories that became known as Marxism. The Communist Manifesto considers history to be a series of conflicts between classes. It predicts that the ruling middle class will be overthrown by the working class. The result of this revolution, according to Marx and Engels, will be a classless society in which the chief means of production are publicly owned.

Das Kapital (Capital) was Marx's major work. He spent about 30 years writing it. The first volume appeared in 1867. Engels edited the second and third volumes from Marx's manuscripts. Both of these volumes were published after Marx's death. The fourth volume exists only as a mass of scattered notes.

In Das Kapital, Marx described the free enterprise system as he saw it. He considered it the most efficient, dynamic economic system ever devised. But he also regarded it as afflicted with flaws that would destroy it through increasingly severe periods of inflation and depression. The most serious flaw in the free enterprise system, according to Marx, is that it accumulates more and more wealth but becomes less and less capable of using this wealth wisely. As a result, Marx saw the accumulation of riches being accompanied by the rapid spread of human misery.

Other writings. Marx and Engels also wrote what today might be called political columns. They discussed all sorts of events in and influences on national and international affairs--personalities, overthrowing of governments, cabinet changes, parliamentary debates, wars, and workers' uprisings.

Marx also wrote about the practical problems of leading an international revolutionary movement. The major source of these comments is his correspondence with Engels and other friends.

Marx's theories

Marx's doctrine is sometimes called dialectical materialism, and part of it is referred to as historical materialism. These terms were taken from Hegel's philosophy of history. Marx never used them, but Engels did and so have most later Marxists. The concepts of dialectical and historical materialism are difficult and obscure and may be unnecessary for an understanding of Marx's theories.

Marx's writings cover more than 40 years. His interests shifted and he often changed his mind. But his philosophy remained surprisingly consistent--and very complex. Aside from the brief Communist Manifesto, he never presented his ideas systematically.

Production and society. The basis of Marxism is the conviction that socialism is inevitable. Marx believed that the free enterprise system, or capitalism, was doomed and that socialism was the only alternative.

Marx discussed capitalism within a broad historical perspective that covered the history of the human race. He believed that the individual, not God, is the highest being. People have made themselves what they are by their own labor. They use their intelligence and creative talent to dominate the world by a process called production. Through production, people make the goods they need to live. The means of production include natural resources, factories, machinery, and labor.

The process of production, according to Marx, is a collective effort, not an individual one. Organized societies are the principal creative agents in human history, and historical progress requires increasingly developed societies for production. Such developed societies are achieved by continual refinement of production methods and of the division of labor. By the division of labor, Marx meant that each person specializes in one job, resulting in the development of two classes of people--the rulers and the workers. The ruling class owns the means of production. The working class consists of the nonowners, who are exploited (treated unfairly) by the owners.

The class struggle. Marx believed there was a strain in all societies because the social organization never kept pace with the development of the means of production. An even greater strain developed from the division of people into two classes.

According to Marx, all history is a struggle between the ruling and working classes, and all societies have been torn by this conflict. Past societies tried to keep the exploited class under control by using elaborate political organizations, laws, customs, traditions, ideologies, religions, and rituals. Marx argued that personality, beliefs, and activities are shaped by these institutions. By recognizing these forces, he reasoned, people will be able to overcome them through revolutionary action.

Marx believed that private ownership of the chief means of production was the heart of the class system. For people to be truly free, he declared, the means of production must be publicly owned--by the community as a whole. With the resulting general economic and social equality, all people would have an opportunity to follow their own desires and to use their leisure time creatively. Unfair institutions and customs would disappear. All these events, said Marx, will take place when the proletariat (working class) revolts against the bourgeoisie (owners of the means of production).

Political strategy. It is not clear what strategy Marx might have proposed to achieve the revolution he favored. An idea of this strategy can come only from his speeches, articles, letters, and political activities. As a guideline for practical politics, Marxism is vague. Marx's followers have quarreled bitterly among themselves over different interpretations and policies.

Marx today

Today, Marx is studied as both a revolutionary and an economist. People realize his importance as a pioneer in the social sciences. Marx has often been attacked because he rebelled against all established societies, because he was an arrogant writer who scorned his critics, and because of his radical views.

As the founder of the Communist movement, Marx is regarded by Communists as one of the greatest thinkers of all time. Many Communists believe his writings are the source of all important truths in social science and philosophy. They believe a person cannot be an intelligent student of society, history, economics, philosophy, and many other fields without studying Marx or his principal disciples.

Scholars in the Western world were slow to recognize the importance of Marx. For many years, few Americans bothered to study his writings. But today, in a variety of fields, it has become essential to have some knowledge of Marx. One of these fields is economics. Although his methods of analyzing capitalism are considered old-fashioned, many scholars recognize the brilliance of this analysis. Many people consider his criticism of capitalism and his view of what humanity has made of the world as timely today as they were 100 years ago. Even the analysis that Marx made of the business cycle is studied as one of the many explanations of inflation and depression.

In sociology, Marx's work is also regarded with respect. Without his contributions, sociology would not have developed into what it is today. Marx did pioneering work in many areas with which sociology deals. He wrote on social classes, on the relationship between the economy and the state, and on the principles that underlie a political or economic system.

Some people still turn to Marx for an explanation of current social, economic, and political evils. But most of them are unlikely to agree with his view of the ease with which workers will overthrow the class system and establish a Communist society.

Nietzsche, Friedrich, (1844-1900), was a German philosopher and classical scholar. He deeply influenced many philosophers, artists, and psychologists of the 1900's.

Classical scholarship. Nietzsche's first book was The Birth of Tragedy (1872). It presented a new theory of the origins of classical Greek culture. Nietzsche believed that Greek culture could best be understood as resulting from a conflict between two basic human drives, the Apollonian and the Dionysian. The Apollonian was represented by Apollo, the god of the sun. The Dionysian was represented by Dionysus, the god of wine and intoxication.

The Apollonian is a drive to create clarity and order. It is a desire for a world in which everything possesses a clear identity and can be distinguished from other things. The Apollonian tendency finds expression in the visual arts, where each form stands out clearly from other forms. Nietzsche argued that, in reality, the world lacks any clear distinctions, that it is confused, chaotic, and cruel. The Apollonian drive tries to redeem the horrors of the real world by giving it the illusion of order and beauty, thus making it tolerable.

The Dionysian is a drive that tries to rip apart Apollonian illusions and reveal the reality that lies behind them. This revelation takes place only in special states of ecstasy or religious frenzy induced by drinking, wild music, and sexual license.

Nietzsche and religion. Nietzsche was a severe critic of religion, especially Christianity. In Thus Spake Zarathustra (1883 to 1885), he proclaimed that "God is dead." This was his dramatic way of saying that most people no longer believed in God. Thus, religion could no longer serve as the foundation for moral values.

Nietzsche believed that the time had come to examine traditional values critically. In Beyond Good and Evil (1886) and The Genealogy of Morals (1887), he examined the origins of our moral systems. He argued that the warriors who dominated earlier societies had defined their own strength as "good" and the weakness of the common people they dominated as "bad." Nietzsche called this "master morality" because it represented the values of the masters.

Later, the priests and common people, who wanted to take power, defined their own weakness and humility as "good." They called the aggressive strength of the warriors "evil." Nietzsche identified these values, which he called "slave morality," with the values of the Judeo-Christian tradition that dominates Western culture. He criticized these values as being expressions of the fear and resentment of the weak against the strong.

Psychological ideas. Nietzsche's major psychological theory states that all human behavior is inspired by a "will to power." He wanted to disprove and replace a common prevalent psychological theory that was known as hedonism. Hedonism holds that human behavior is inspired by a desire to experience pleasure and avoid pain. Nietzsche argued that people are frequently willing to increase their pain, strain, or tension to accomplish tasks that allow them to feel power, competence, or strength.

Nietzsche did not mean that people wanted only to dominate each other, nor that they were only interested in physical or political power. He wrote that we also want to gain power over our unruly drives and instincts. He thought that the self-control exhibited by artists and people who practice self-denial for religious reasons was actually a higher form of power than the physical bullying of the weak by the strong.

Nietzsce's ideal was the overman (or superman), a passionate individual who learns to control his or her passions and use them in a creative manner. This superior human being channels the energy of instinctual drives into higher, more creative, and less objectionable forms. Nietzsche believed that such "sublimation" of energy is far more valuable than the suppression of the instincts urged by Christianity and other religions.

His life. Nietzsche was born in Rocken, Saxony, near present-day Leipzig, Germany. He was a professor of classics at the University of Basel in Switzerland from 1868 to 1878, when he retired because of poor health. He then devoted himself to writing. In 1889, Nietzsche suffered a mental breakdown from which he never recovered. Nietzsche is often wrongly considered a racist, anti-Semite, and forerunner of Nazism. These charges are largely the result of distortions of his ideas by his sister, Elisabeth, and by Nazi propagandists after his death.

Bentham, Jeremy (1748-1832), an English philosopher, founded the philosophy known as utilitarianism. He thought that ideas, institutions, and actions should be judged on the basis of their utility (usefulness).

Bentham defined utility as the ability to produce happiness. He advocated the production of the greatest possible amount of happiness in and for society. Bentham thought of happiness and good in terms of pleasure. He believed that (1) pleasure can be exactly measured, (2) individuals care only about increasing their own pleasure and decreasing their pain, and (3) a person should always do what will produce the greatest good for the greatest number of people. Bentham set up a number of principles for measuring pleasure. He also sought an opportunity to organize a country's laws and institutions in such a way that they would place the general good above each person's individual pleasure.

His criticisms brought about many needed reforms. For example, in Britain the law courts were reformed because they had not promoted the good of all.

Bentham's writings include Fragment on Government (1776) and Introduction to the Principles of Morals and Legislation (1789). He was born in London. Bentham graduated from Queen's College, Oxford, in 1763.

John Stuart Mill (1806-1873) became the leader of the utilitarian movement. Mill was one of the most advanced thinkers of his time. He tried to help the English working people by promoting measures leading to a more equal division of profits. He favored a cooperative system of agriculture and increased rights for women. He served as editor of the Westminster Review from 1835 to 1840 and wrote many articles on economics.

His greatest philosophical work, System of Logic (1843), ranks with Aristotle's work in that field. Mill applied economic principles to social conditions in Principles of Political Economy (1848). His other works include Utilitarianism (1863), On Liberty (1859), The Subjection of Women (1869), and Autobiography (1873).

Mill was born in London and was educated by his father. By the age of 14, he had mastered Latin, classical literature, logic, political economy, history, and mathematics. He entered the East India Company as a clerk at 17. Like his father, he became director of the company. Mill was elected to Parliament in 1865.

Mill was the family name of three British writers--father, son, and the son's wife. They won distinction in philosophy, history, psychology, and economics.

James Mill (1773-1836) established his reputation as a writer with the publication of A History of British India (1817). This work was partly responsible for changes in the Indian government. It also won him a job with the East India Company in 1819. He headed the company from 1830 until his death.

In 1808, Mill met Jeremy Bentham, a political economist called the father of utilitarianism. The utilitarians believed that the greatest happiness of the greatest number should be the sole purpose of all public action. Mill adopted the utilitarian philosophy and became Bentham's ardent disciple and the editor of St. James's Chronicle.

His writings helped clarify the philosophical and psychological basis of utilitarianism. Analysis of the Phenomena of the Human Mind (1829) is a study of psychology. He wrote Elements of Political Economy (1821) for his son, and it became the first textbook of English economics.

In Fragment on Mackintosh (1835), he states his views of utility as the basis of morals.

Mill was born in Scotland and graduated from Edinburgh University, where he studied for the ministry. He became a Presbyterian minister in 1798 but left the ministry in 1802 to become a journalist.

Harriet Taylor Mill (1807-1858) was the wife of John Stuart Mill and helped him write many of his works. She called for increased rights for women and workers and greatly influenced Mill's writings in these areas.

Many of John Stuart Mill's writings probably originated from discussions with Harriet. She helped him write Principles of Political Economy. Some scholars also consider her the coauthor of On Liberty, The Subjection of Women, and Autobiography, all of which were published after her death. But only the essay "Enfranchisement of Women" bears her name. It appears in her husband's Discussions and Dissertations, a four-volume work published from 1859 to 1875. In the introduction to On Liberty, he calls Harriet "the inspirer, and in part the author, of all that is best in my writings."

She was born Harriet Hardy in Walworth, near Durham, England. In 1826, she married John Taylor, a merchant. Harriet met John Stuart Mill about 1830, and they became close friends. Taylor died in 1849, and she married Mill in 1851.

Sartre, Jean-Paul, (1905-1980), was a French existentialist philosopher who expressed his ideas in novels, plays, and short stories, as well as in theoretical works.

The bare existence of things, especially his own existence, fascinated and horrified Sartre, because there seems to be no reason why anything should exist. In his first novel, Nausea (1938), he described the horror and mystery which a man experiences when he considers the unexplainable fact of a thing's existence.

In his chief philosophical work, Being and Nothingness (1943), Sartre investigated the nature and forms of existence or being. He claimed that human existence, which he called "being-for-itself," is radically different from the existence of such inanimate objects as tables, which he called "being-in-itself." Sartre said that only human existence is conscious of itself and of other things. He argued that inanimate objects simply are what they are; however, people are whatever they choose to be. Sartre said that a person is not a coward, for example, in the same simple way that a table is only a table. A person is a coward only by choice. Sartre said that a person, unlike a table, has no fixed character or "essence" that has been assigned. Primarily, people "exist" as beings who must choose their own character or "essence." Thus, in his essay Existentialism and Humanism (1946), he defined existentialism as the doctrine that, for humankind, "existence precedes essence".

Sartre believed that people are completely free, but are afraid to recognize this freedom and to accept full responsibility for their behavior, which such freedom implies. Thus, people tend to deceive themselves about their true situation. Throughout his philosophical and literary works, Sartre examined and analyzed the varied and subtle forms of self-deception.

Sartre criticized Sigmund Freud's psychoanalytic theory of human behavior and offered his own "existential psychoanalysis". Sartre said the ultimate motive for all human behavior is the desire to achieve perfect self-sufficiency by becoming the cause of one's own existence. However, he argued that this goal is self-contradictory and impossible to attain. Therefore, he considered all human activity ultimately futile. As Sartre said: "Man is a useless passion." He identified this idea of perfectly self-sufficient beings who are the cause of their own existence as the traditional idea of God. According to Sartre, each of us wants to become God, and God cannot possibly exist. In the Critique of Dialectical Reason (1964), Sartre presented his political and sociological theories, which he considered to be a form of Marxism.

Sartre's plays include The Flies (1943), No Exit (1944), Dirty Hands (1948), and The Condemned of Altona (1959). He wrote The Roads of Freedom, a sequence of novels including The Age of Reason (1945), The Reprieve (1945), and Troubled Sleep (1949). He applied his psychoanalytic theories in his biographies, Baudelaire (1947), Saint Genet (1953), and Flaubert (1971). Words (1963) is an autobiographical account of his youth.

Sartre was born in Paris where he studied at the Ecole Normale Superieure. During World War II (1939-1945), he fought in the French Army and was active in the French resistance movement. Sartre founded the monthly review Les Temps Modernes in 1945 and served as its editor. In 1964, Sartre was awarded the Nobel Prize for literature. However, he refused to accept the award.

Edmund Husserl, (1859–1938) a German philosopher not usually considered an existentialist but the founder of his own movement, phenomenology, was nevertheless one of the greatest influences on existentialism.

Phenomenology was developed in the early 1900's. Husserl wanted to understand how consciousness works in order to better understand human experience. Consciousness refers to the power of the mind to be aware of acts, sensations, and emotions. Husserl believed that everything we know about reality derives from our consciousness.

For phenomenologists, experience has two parts. The first part consists of objects of consciousness (the things of which one is conscious). Objects of consciousness, which include material objects, ideas, and wishes, are called phenomena. The second part of experience consists of acts of consciousness, such as perceiving, believing, thinking, and desiring. Phenomenologists believe that all acts of consciousness are related to objects of consciousness and thus must also be considered phenomena. This relationship is called intentionality.

The phenomenological method starts with the theory that people normally make certain assumptions about their experiences. They consider the things they have been taught, and remember past experiences. Such presuppositions limit their experiencing of phenomena. Phenomenologists realize that it is impossible to entirely eliminate these presuppositions from the mind. Instead, they try to expand their experiencing of phenomena by dealing with the presuppositions critically. One critical method involves fantasy variations. The philosopher varies the presuppositions, imagining how the experience would be perceived under varying circumstances. The features of the experience that remain constant despite the variations are considered its essence.

Husserl has had many followers. They include the French psychologist Maurice Merleau-Ponty and the German philosopher Martin Heidegger. Both men argued that phenomenology should not be limited to an analysis of consciousness. Instead, they used the phenomenological method to analyze human existence in general. The method has also been successfully applied to specific fields, such as anthropology, law psychiatry, psychology, religion, and sociology.

James, William (1842-1910), became the most widely read American philosopher of the 1900's. With Charles S. Peirce and John Dewey, he led a philosophical movement called pragmatism .

Early career. James, the brother of the novelist Henry James, was born in New York City. As a medical student at Harvard University, he studied anatomy and physiology under the naturalist Louis Agassiz. Later, James's interests turned to psychology and the relationship among experience, thinking, and conduct. His The Principles of Psychology (1890) is considered a classic.

Neither physiology nor psychology could satisfy James's interest in the human condition. He was basically a philosopher who believed in the supreme importance of ideas. His own experiences had forced him to raise philosophical questions. James struggled to find his life's work. Depression over his inability to reach a decision led him to the verge of despair. He finally became convinced that people could devote their lives to finding new answers to such ancient questions as: Can human effort change the course of events? Does God exist? What difference would His existence make to people? What is the good life? How does a person's conviction about what is good affect his or her actions?

His beliefs. James tried to answer philosophical questions in pragmatic terms. He believed that every difference in thinking must make a difference to someone, somewhere. If two theories differ, the difference becomes clear when we know (1) how they differ over what the facts are, and (2) the difference in our behavior if we believe that one or the other is true.

One person may claim that people are free and can make real choices. Another may claim that people are not free because all human decisions and actions are determined by factors beyond their control. These claims cannot both be true. Therefore, according to James, we must find a way to decide between them because our conduct depends on which we adopt. James proposed that we approach such questions by tracing the consequences of each viewpoint. If we are free, we can make decisions. We are responsible for our actions. We can regret some of our actions and can say that the world would be better if such actions had not been carried out. If we are not free, we do not choose our actions. We are not responsible for our actions, and it makes no sense to speak about something happening differently from the way it did happen.

James did not claim to have solved difficult philosophical problems for all time. He tried to put them into a form that would make it easier for people to solve the problems for themselves. All people, James believed, must make up their own minds on issues of human life and destiny that cannot be settled on scientific grounds. James wrote a famous essay called "The Will to Believe" (1896). It states that if we believe in the possibility of some future event taking place, this belief increases our power to help make the event happen when the time comes for action. James's other works include Varieties of Religious Experience (1902), Pragmatism (1907), and The Meaning of Truth (1909).

Dewey, John (1859-1952), was an American philosopher and educator. He helped lead a philosophical movement called pragmatism.

Dewey was strongly influenced by the then-new science of psychology and by the theory of evolution proposed by the English scientist Charles R. Darwin. Dewey came to regard intelligence as a power that people use when they face a conflict or challenge. He believed that people live by custom and habit. In most situations, it is sufficient to think and act as we have done in the past, but some physical and social situations present problems calling for new responses. According to Dewey, we cannot solve such problems by habitual action and thought. We must use intelligence as an instrument for overcoming any obstacles. Dewey's philosophy is thus called instrumentalism.

Dewey believed that knowledge is a means of controlling the environment, hopefully to improve the quality of human life. He wrote widely on art, democracy, education, philosophy, and science. In his writings, Dewey always focused on the same problem--how to close the gap between thought and action. Dewey's interpretation of science shows how thought and action are united. He considered science as a method for inquiring into the behavior of things. The results of such inquiry are the joint products of thought and activity. Dewey regarded activity as conducting experiments under controlled situations and thought as those theories that guide our experiments.

In every area of life, Dewey called for experimenting and trying out new methods. As an educator, he opposed the traditional method of learning by memory under the authority of teachers. He believed that education should not be concerned only with the mind. Students should develop manual skills. Learning must be related to the interests of students and connected with current problems. Dewey declared that education must include a student's physical and moral well-being as well as intellectual development.

In Art as Experience (1934), Dewey connected works of art with the experiences of everyday life. He wrote that daily experience can be glorious, joyous, sad, tedious, terrifying, and tragic. These, he said, are the qualities that architects, composers, painters, and writers seek to capture and express in their works. Dewey regarded education as incomplete if it ignores these experiences.

Dewey was born in Burlington, Vermont. He had a distinguished teaching career at several universities, especially at Columbia University from 1904 until his retirement in 1930. Dewey's works include Democracy and Education (1916), Reconstruction in Philosophy (1920), and Experience and Nature (1925).

Russell, Bertrand (1872-1970), was a British philosopher and mathematician. Russell ranks among the greatest philosophers of the 1900's. He has also been called the most important logician (expert in logic) since the ancient Greek philosopher Aristotle.

Russell made his most important contributions in formal logic and the theory of knowledge. However, his influence extends far beyond these fields. Russell developed a prose style of extraordinary clarity, wit, and passion. He received the 1950 Nobel Prize for literature.

Russell became an influential and controversial figure on social, political, and educational issues. He was an outspoken pacifist and advocated extremely liberal attitudes toward sex, marriage, and methods of education. Russell was a critic of World War I (1914-1918). He was imprisoned in 1918 for statements considered harmful to British-American relations, and again in 1961 for "incitement to civil disobedience" in a campaign for nuclear disarmament.

Russell made his major contributions to philosophy and mathematics in the early 1900's. He wanted to derive all of mathematics from logic, thus putting it on a sure foundation. Russell collaborated with the English mathematician and philosopher Alfred North Whitehead on the monumental three-volume Principia Mathematica (1910-1913). This work attempts to show that all pure mathematics follows from premises that are strictly logical and uses only those concepts that can be defined in purely logical terms. Although Russell's ideas have been refined and corrected by later mathematicians, all modern work in logic and the foundations of mathematics begins with his ideas.

Russell made important contributions to the history of philosophy in such books as A Critical Exposition of the Philosophy of Leibniz (1900) and A History of Western Philosophy (1945). He expressed his social and political ideas in a number of works, including German Social Democracy (1896), Roads to Freedom (1918), Power (1938), and Authority and the Individual (1949). Russell also influenced morality and education in essays and such books as Why I Am Not a Christian (1927), Marriage and Morals (1929), and The Conquest of Happiness (1930). Russell wrote many accounts of his life, including a three-volume autobiography (1967 to 1969).

Russell was born near Trellek, Wales, north of Chepstow. His full name was Bertrand Arthur William Russell. He was a member of an old and noble family. In 1931, he inherited the family title and became Earl Russell.

Wittgenstein, Ludwig, (1889-1951), was one of the most important philosophers of the 1900's. His ideas greatly influenced two philosophical movements, called logical positivism and linguistic analysis.

In his later work, Wittgenstein suggested that most philosophical problems result because philosophers think most words are names. For example, philosophers have asked, "What is time?" and they have been puzzled because they could not find any thing named time. Wittgenstein said this is the wrong way to find out what time is. What is necessary is to determine how the word time is used in ordinary language. In the sentence, "It is time to go home," we know what time means, and so its meaning is not a problem. In general, the meaning of a term is determined by public standards of judgment, so a necessarily "private language" is impossible. Wittgenstein claimed that this way of viewing language "dissolves" many traditional problems of philosophy. His approach to language has greatly influenced scholars in many fields.

Wittgenstein was born in Vienna, Austria. He studied at Cambridge University in England and later taught there. He gained recognition for his books Tractatus Logico-Philosophicus (1921) and Philosophical Investigations (published in 1953, after his death).

IV. Give a brief talk on one of the following topics:

1. Confucianism as a system of ethical principles for the management of society.

2. Socrates and his question-and-answer method of teaching as a means of achieving self-knowledge.

3. Plato’s dialogues and his intention to show the rational relationship between the soul, the state, and the cosmos.

4. Aristotle's work is the basis of medieval scholasticism.

5. Zeno of Citium and his strict ethical doctrine.

6. Cicero, the greatest Roman orator, a stoical philosopher. His mastery of Latin prose.

7. Marcus Aurelius- Roman emperor and philosopher. His spiritual reflections on stoicism.

8. Epictetus and his doctrine of brotherhood.

9. Epicurus and his code of social conduct.

15. St.Albertus Magnus and his attempt to reconcile Aristotelianism with Christian thought.

28.John Locke, founder of British empiricism.

31.J.J.Rousseau and the theory of the ‘natural man’.

32. Voltaire and the French Enlightenment.

35.Hegel and his supposition that truth is reached by a continuing dialectic.

37.Friedrich Wilhelm Nietzsche, an individualistic moralist rather than a systematic philosopher.

39.John Stuart Mill and his interpretations of empiricism and utilitarianism.