Interaction is objective, universal and active in character. The properties of an object can be manifested and cognized only in in­teraction with other objects.

The category of interaction is an important logical-methodological and epistemological principle of the study of natural and social phenomena. Modern natural science has shown that any interaction is connected with material fields and is accompanied by trans­ference of matter, motion and information.

The existing classifications of interactions are based on the dif­ferentiation between force interactions and informational interac­tions. In physics, four principal types of force interaction are known: gravitation, electromagnetism, and weak and strong interactions. They provide a key to an understanding of an infinite variety of pro­cesses. Each type of interaction in physics is characterized by a defi­nite measure.

Biology studies energy and informational interactions at various levels: molecular, cellular, organism, population, species, biocenosis. Even more complex interactions are found in the life of so­ciety, for society is the process and product of people's interaction with nature and among themselves. People's spiritual world is or­ganized through semantic (psychological, logical, moral-aesthetic, and other) interactions. The interactions in the social sphere are realized not only in closed social systems, but also within mankind as a whole.

Without a study of interaction in its general and concrete mani­festations, it is impossible to understand either the properties or the structure or the laws of reality. It is in the process of interaction that the essence of interacting objects and their properties are realized.

Contradiction, or interaction of opposites, proves to be the deep­est source, the basis, and the ultimate cause of the emergence, self-motion and development of objects. Without clarifying the forms and content of various kinds of connection and interaction in nature and society, it would be impossible to handle adequately the prob­lem of development, which is the second fundamental principle of materialist dialectics.

2. The Idea of Development and the Principle of Historism.

There is nothing ultimately complete in the world: everything is on the path towards something else. The principle of the motion of matter as a mode of its existence, combined with the principle of universal connection, gives a general idea of the development of the world. Development is an irreversible, definitely oriented and law-governed change of ma­terial and ideal objects resulting in the emergence of new qualities.

What does irreversible change mean? It means that in the pro­cess of development, as distinct from the cyclical functioning of a system, return to already passed states is impossible. Everything passes through one and the same state only once; thus the move­ment of an organism from old age to youth is impossible. This example shows already the direction of development. Therefore the next characteristic—definitely oriented change —means that changes of the same quality are gradually accumulated in the pro­cess of development, being determined by the type of interaction of the given object with the surrounding world and by its inner contra­dictions. The sum total of such changes determines the line of the object's directed change

And what does law-governed change mean? It means that under­lying development are not accidental events, of which the infinite numbers disturb the object's oriented change, but rather the neces­sary events that follow from the very essence of the object and from the type of its interactions with the surrounding world

All three features of development pointed out here inevitably draw attention to the fourth trait —emergence of new qualities which are, as it were, a definite summing up of the previous devel­opment and the starting moment of the subsequent one. Progressive development is thus thought of not as movement of some object from one point to another but as a process which, at each sub­sequent stage of its further movement, raises higher and higher the whole mass of already attained content and, far from losing some­thing essential, carries with it all that it has accumulated, bringing in new content. The new is an intermediate or final result of develop­ment correlated with the old. Develop­ment is a dual process: the old departs and the new comes in, as­serting itself in the struggle against the old rather than through un­hampered unfolding of its potential.

The relationship between the concepts of development and pro­gress must be clearly understood. They are close to each other but not identical. Development results in the appearance of a new

quality, but it is not at all necessary that this quality should be more complex or more perfect than the previous one. If the new quality is in some respect superior to the old one, we have a progressive tend­ency of development, and if it is inferior, we have a regressive tend­ency. Progress and regress are two different tendencies of development which, however, are intertwined with one another, forming a complex interdependence

Progress and regress actually coexist in objective reality, as do deformation, decay, revolutionary (leap-like) and evolutionary changes, spiral and cyclical material processes, i.e. there coexist two opposing directions of development —along the ascending and the descending line. Development along the ascending line is develop­ment from the elementary towards the complex, more perfect, more finely organized, towards a richer potential and greater information volume, a process in which the structure becomes more refined,

matter and energy accumulate, and the extent of coded information grows. Descending development is the path of decay, degeneration, impoverishment and decomposition.

From the moment of the assertion of historical thought in the 19th century, the debate has never ceased about the essence of the process of development, and of its motive forces. Metaphysical theories challenge the very essential content of development — the emergence of new qualities; development is interpreted as mere growth or decrease of a quality or as repetition of it, so that the problem of contradiction as the source of development is eliminated.

Rejecting internal contradictions as the source of development, metaphysics cannot find in matter itself the true causes for this pro­cess and therefore often resorts to supernatural forces. The dialecti­cal conception, on the other hand, primarily stresses the source of self-motion and self-development. "The first conception is lifeless, pale and dry. The second is living. The second alone furnishes the key to the 'self-movement' of everything existing; it alone furnishes the key to the 'leaps', to the 'break in continuity', to the 'transforma­tion into the opposite', to the destruction of the old and the emer­gence of the new."'

There is nothing mysterious about the concept of self-motion. It merely means that the source of development is inherent in the de­veloping object itself, which interacts with others. The development of any system is realization of the universal principle of being —the activeness and inner striving of all that is towards self-expression in infinite forms of interaction. Development is a form of motion, and the latter is an attribute of matter, a mode of its existence, inherent in it and not inferred from anything. The self-motion of matter on the whole is not conditioned by any external factors, while the self-motion of the concrete forms and kinds of matter is conditioned by internal and external causes. If the self-motion of matter is absolute, the self-motion of concrete systems is relative: the higher the level of the organization of a system, the greater its independence in be­havior, and consequently in its development.

THE BASIC LAWS OF DIALECTICS.

The concept of law. Practical experience constantly demonstrates that the processes going on in the world are not a chaos of raging elemental forces. The universe has a code of laws of its own. Every­where we observe order coextensive with the world: the planets move along their strictly determined paths; however long a night may be, day will inevitably come; the young grow old and depart this life with implacable necessity, and a new generation is born to re­place the older one. A watermelon or strawberries cannot grow out of an acorn, neither does time flow in reverse — winter never follows

spring. Everything in the world, beginning with the motion of physi­cal fields, elementary particles, atoms, crystals, and ending with giant cosmic systems, social events and the realm of the spirit, is subject to regularity.

Century after century man noted the strictly determined order of the universe and recurrence of various phenomena; all this sug­gested the idea of the existence of something law-governed. The concept of law is a product of mature thought: it took shape at a late stage in the formation of society, at a time when science evolved as a system of knowledge.

A law is an essential, stable, regular and necessary type of connec­tion between phenomena considered in a generalized form and ad­justed to the typologically classified conditions of its manifestation. Laws as relations of essence or between essences are guarantees of the world's stability, harmony, and at the same time its develop­ment.

Being in their form (or formulation) the products of human knowledge, m their inner content laws express objective processes of reality. The study of laws is the principal task of science. Scien­tists are constantly searching for regularity, order, stable tendencies in phenomena, that is, for law-governed connections. Man's power over nature and history is measured by Ihe extent and depth of his knowledge and ability to use their laws.

Classification of laws. Law and regularity. According to the sphere of the application, laws are divided into universal (e.g., the law of conservation of energy, or the dialectical laws which we shall discuss below) and particular ones, valid only in a limited area, as e.g. the laws of social development, which are only manifested at the level of the social form of the motion of matter.

According to their inner content, laws are divided into the laws of the structure (these are mostly laws expressing the necessary cor­relative connections in systems), the laws of functioning (the joint area of causal and systemic determination) and the laws of develop­ment (the area of primarily causal determination, which has both explanatory and predictive value).