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Thus, the body is supplied with air not only via two different sets of
organsbutalsoviatwodifferent motions: one psychic and one physical,
voluntary and involuntary, respe ctively. The reason why two types of
breathing are necessary for the body is laid out clearly at the end of On
theUsefulnessofRespiration. Whereas all of the body is able to breathe
sufficiently through the arteries, there are two special organs o f breathing,
the lungs and the nostrils, serving two central organs – the heart and the
brain, respectively.
Galen proceeds to explain the importance of the
system t hat moderates the innate heat for the sake of the maintenance of
life as follows:
τῶνμὲνοὖν ἄλλων ὀργάνων αἱ βλάβαι τῶν ἐνεργειῶν μικραί, τῶνδ’ εἰς
αὐτὴντὴνζωὴν διαφερόντων μεγάλαι, τῶνδ’ οὐ μόνον εἰςαὐτὴντὴνζωὴν
διαφερόντων, ἀλλὰ καὶ πρὸςτὰἄλλα λόγον ἀρχῆς ἐχόντων μέγισται.
τοιαῦτα δ’ ἐστὶν ἐγκέφαλός τε καὶ καρδία. ὥσθ’ ἡ τούτων τῆς
κατασκευῆς βλάβη παραχρῆμα βλάψει τὴν ζωήν. ἀλλ’ οὐδὲν
ὑπαλλάττειν αὐτὴνοἷον τέ ἐστιν ἑτοιμότερον ἀμέτρου θερμασίας. ὥστε
ἄμφω δέδεικται διὰ τοῦ λόγου τοῦδε, τό χρήσιμον τῆς συμμέτρου
θερμασίας <καὶ> τὸἐντῇἀναπνοῇ εἰςαὐτήν.
Injuries to the activities of other organs are minor; injuries to those
essential to life are great; but injuries to those that not only are essential
to life but also have the status of principles with respect to the others are
the greatest: and such are the brain and the heart. So injury to the
composition of these will immediately injure life. But nothing is able to
change it more readily than immoderate heat. So both the value of heat in
moderation and of bre athing in regard to this have been shown by the
argument.
Thus, Galen makes it quite clear that both types of breathing are
required to maintain the vitality. Respiration helps to ensure the proper
heat regulation in the key governing organs, while transpiration serves
the rest of the body. This conclusion naturally raises the further ques-
tion of how breathing contributes to the functioning of the body.
In other words, what purpose does breathing accomplish to make it
so crucial to vitality that even a relatively brief cessation poses the risk
Ut. Resp. . ( Furley and Wilkie¼.K).
Ut. Resp. . ( Furley and Wilkie¼.K), tr. Furley and Wilkie (: ). Galen also wrote
a separate treatise specifically dedicated to the topic of the innate heat, but it is not extant; see
Durling () for a reconstruction of the lost treatise. The very notion of the innate heat, of
course, precedes Galen. An extensive study dedicated to this notion in antiquity is Mendelsohn
().
Respiration and Transpiration
of death? Galen’s attempts to answer this question are discussed in
Section ..
. The Vital Pneuma and the Purpose of Breathing
When it comes to breathing, Galen outlines succinctly the most important
puzzle at the very beginning of On the Usefulness of Respiration: the great
usefulness of respiration is evident from the fact that animals are unable to
survive once their respiration is in some way obstructed. But what makes
respiration so fundamental to animal vitality? Galen starts his enquiry by
presenting an overview of the prominent theories of his predecessors.
Asclepiades maintained that breathing is the source of the soul. According
to Praxagoras, it is a kind of nourishment for the soul. Philiston and
Diocles claimed that breathing is useful for the cooling of the innate heat.
Hippocrates’ view is a kind of combination of the latter two views: the use
of breathing is both nourishment and cooling. Finally, Erasistratus stated
that its purpose is to replenish arteries. Galen notes that some of these
views, although they appear different, have the same outcome. For
example, claiming that breathing strengthens the innate heat and claiming
that it fans the innate heat amounts to the same view: breathing maintains
the innate heat.
Thus, all the listed theories pertain either to the
substance of the inspired air or to its quality.
If pneuma is called either
nourishment or the substance of the soul or the filling of arteries, then
animals breathe in order to supply substance to their bodies. Fanning,
strengthening or cooling, meanwhile, concerns quality, and in that case,
animals breathe for the sake of some qualitative alteration by means of
pneuma. Thus, Galen narrows down the focus of the treatise to the
question of whether pneuma is useful because of its substance or because
of its quality.
That Galen’s selection and report is quite odd in general was noted in van der Eijk (: –),
with a suggestion that Galen might have been engaging with a doxographic tradition.
Ut. Resp. . ( Furley and Wilkie¼.K).
Although this appears to be a Galenic classification, see Lewis and Gregoric (: –) for an
argument that De Spiritu is a predecessor for this division. Strictly speaking, in Galenic text, the
Asclepiadean theory could be put into the third category, because it has more far-reaching
consequences than any of the other substance theories. Yet Galen puts Asclepiades’ theory aside
(ultimately grouping him with the substance theorists) as impossible to investigate due to the fact
that the substance of the soul is unknown. He acknowledges that there appears to be a connection
between the soul and breathing, because breathing maintains life, but it is not something that one
can understand fully without knowing the substance of the soul.
‘Both’ is also an option and, to an extent, Galen’s account ends up being a combination of these
answers, although he clearly thinks that the primary purpose is the latter.
. The Vital Pneuma and the Purpose of Breathing
From early on in the treatise, it is quite clear that Galen favours the
latter. His advocacy of his preferred option consists of giving explanations
of certain scenarios in a polemical manner. For example, the investigation
begins with the argument that humans suffocate when they breathe in and
hold the breath. This shows that the use of breathing is not just the
substance of air but also some of its qualities.
But presenting an explan-
ation is not enough; Galen also sets out to refute the rival accounts.
His main rival in this case, and mostly throughout the rest of the
treatise, is the Alexandrian doctor Erasistratus. His explanation is steeped
in a distinctively Erasistratean understanding of human physiology, and
thus, Galen is killing two birds with one stone: advocating both his
account of respiration and his understanding of the principles governing
human physiology. According to Erasistratus, a person suffocates while
holding breath with lungs full of air because the heart cannot draw air from
the lungs when breathing stops. The heart cannot draw the air owing to
the principle of horror vacui.
If the heart draws in some air, the place
previously occupied by that air would become empty, which is
impossible.
Galen pivots his rejection of the Erasistratean account on the attack of
horror vacui. The rebuttal consists of three arguments. Only the last is
presented as his own, the first two criticisms come from unnamed critics of
Erasistratus. First, they point out that he only proves that the void does not
exist en masse while the possibility that it might be dispersed throughout
the solid bodies remains.
Second, these critics point out that the sub-
stance could stretch out in all directions, thus filling up greater space. This
criticism is less obvious and deserves to be unpacked. Erasistratus’ horror
vacui-driven physiology relies of the constant replacement of matter as an
operating principle. The impossibility of void motivates the replacement of
one amount of matter by another amount of matter, and this change
constitutes various physiological processes.
The critics, however, point
Ut. Resp. . ( Furley and Wilkie¼.K).
I am describing this as a principle because, as Berryman () shows, there is no good evidence to
suppose it was a theory; see also Berryman (: –) for some problems with the conjecture
about the unity of this theory, originally proposed by Diels (). See also Debru (: –)
and Vallance (: –).
Ut. Resp. . ( Furley and Wilkie¼.K).
Ut. Resp. . ( Furley and Wilkie¼.K), see also Nat. Fac. . (, –
Helmreich¼.K) and Adamson (: –) for the reconstruction of Erasistratus’
argument.
Constant change is, of course, a premise in Galenic medicine as well, except that it is the qualitative
change of mixture, triggered by various external and internal factors; see, for example, San. Tu.
..– Koch (.K).
Respiration and Transpiration
out that, in principle, there is no reason to suppose that one amount of
matter is being replaced with another rather than, for instance, that very
same amount of matter stretches over a larger space, thus becoming
thinner. The air could move from the lungs to the heart by extending.
Although he presents this argument, Galen is not necessarily an advocate
of the stretching-matter explanation. A little later in the treatise, he puts
this option aside, saying that this debate is too inconclusive on both
sides.
But these arguments of the critics are enough to show that
Erasistratus’ views have a history of refutations, and then Galen adds one
of his own to this collection.
Hisargumentismoreanatomicalthanphilosophical.Galenpoints
out that Erasistratus’ scenario would entail the heart not moving the
entire time when the breath is held, but this is not the case.
He also
eliminates the possible objections and alternative accounts, namely, the
counter-argument of the followers of Erasistratus stating that t he heart
only draws from the great artery rather than from the lungs,
and the
argument that the heart doe s not contract or dilate but only oscillates,
associated with Asclepiades and his followers.
The Erasistrateans are
refuted b y drawing attention to the fact that the valves of the he art
prevent it from drawing the blood from the great artery, and this point
was shown by Erasistratus himself.
In addition to this, Gale n points
out that, according to Erasistratus’ own anatomy, nothing ought to
prevent the heart from drawing air from the lungs, because he agrees
that the thorax is moved voluntarily, which means that it ought to be
possible to constrict the t horax on all sides and move the air from the
lungs to the heart while keeping the upper part of the thorax closed.
In order to refute the Asclepiadeans, Galen presents an overview of the
movements of arteries during the suspension of breathing, showing that
it is impossible for arteries to eit her stop working (as would be the case
Especially given that it is a λεπτομερὲς body. This term, especially prominent in Galenic
pharmacology (see Debru ), is also applicable to pneuma; see MM . (.K).
Ut. Resp. . ( Furley and Wilkie¼.K).
Ut. Resp. . (– Furley and Wilkie¼.–K).
Ut. Resp. . ( Furley and Wilkie¼.K).
Ibid. Galen calls this view foolish and already refuted by Athenaeus, while providing his own
refutation nonetheless.
Ut. Resp. . ( Furley and Wilkie¼.–K). See also Adamson (: –).
Ut. Resp. . ( Furley and Wilkie¼.–K). To reinforce the conclusion that it is, in fact,
possible for the air to move from the lungs to the heart while holding one’s breath, Galen offers an
experiment. One only needs to breathe in, hold the breath and notice that the heart beats during
that time.
. The Vital Pneuma and the Purpose of Breathing
if the heart merely oscillated) or that the movement in the arteries
doubles in such cases.
These refutations support the main argument of the treatise, namely,
the heart requires not the substance but the quality of pneuma. The
argument is further reinforced by counterfactuals: if the opposite were
true, the large quantity of air breathed in (i.e., overabundance) would not
cause greater distress.
The desire to breathe out while holding one’s
breath shows that one requires more than just the substance of pneuma.
The expansion of heart and arteries while a person is holding breath shows
that there is no lack of pneuma in the body, and therefore suffocation takes
place not by the lack of its substance but its quality.
Not all of the scenarios Galen presents are preoccupied with anatomy.
One of the more vivid case studies is the phenomenon when people
suffocate in the Charonian pits, newly whitewashed houses and so on.
The Erasistratus-style explanation is that the air is so thin in these places
that it cannot be contained in the arteries, and consequently death due to
the lack of pneuma ensues. Galen rejects this explanation by arguing that it
provides no reason why the air becomes thin in these conditions to begin
with, or how arteries cannot contain air, or that there is not a different
cause that is harder to discover. Furthermore, the motion in the arteries in
these conditions is not observed to be changing.
His own explanation –
that the quality of pneuma in these locations is altered, making respiration
impossible – fits the bill much better. Thus we again arrive at the
conclusion that the respiration maintains vitality primarily owing to the
elemental qualities of pneuma rather than its substance.
Ut. Resp. . ( Furley and Wilkie¼.–K). He also attacks the Erasistrateans who – against
Erasistratus’ own views – appear to be unable to determine that the arteries are emptied out during
the suspension of breathing (Ut. Resp. . ( Furley and Wilkie¼.K)).
Ut. Resp. . ( Furley and Wilkie¼.K).
Ut. Resp. . ( Furley and Wilkie¼.K).
Ut. Resp. . ( Furley and Wilkie¼.K). See also UP . (., –,
Helmreich¼–K), tr. May (: –):
Now when it becomes necessary to account for suitable and unsuitable qualities in air,
Erasistratus for some reason or other says that they are caused by its thinness or thickness and
supposes that this is the reason why people die in Charonian caverns or in houses freshly coated
with lime, and why some die of [inhaling] the odor of burning charcoal or other such vapors, viz.
they die because the air, being too thin, cannot be retained in the body.
Ut. Resp. . ( Furley and Wilkie¼.K).
As ever with Galen, there is a caveat to this. Galen hastens to add that he only rules out that the
replenishment of the substance of pneuma is the sole use of respiration. He intends to show that
humans suffocate when deprived of breath because the substance of the psychic pneuma is not
replenished, and therefore his argument so far does not rule out the possibility that the psychic
pneuma is nourished by respiration; see Ut. Resp. . ( Furley and Wilkie¼.K).
Respiration and Transpiration
.. The Innate Heat: The Flame Model
Having determined that pneuma must act qualitatively, Galen sets out to
elucidate the details: what are the qualities that pneuma supplies? One
might suppose that pneuma acts by cooling,
because of the desire to
breathe in deeply during febrile illnesses. However, the desire to breathe in
occurs during chilling diseases as well.
After an interlude,
Galen
considers what is common in all of the views that maintain that the
primary use of respiration is qualitative change.
He states that, although
these theories are not all clear or articulate, they all refer to the preservation
of the innate heat, modelled on the phenomenon of the flames in the
following way:
ταύτας γὰρ ἐναργῶς ὁρῶμεν οὕτως ταχέως ἀπολλυμένας, ὅταν
ἀποστερηθῶσιν ἀέρος, ὥσπερ τὰ ζῷα, καθάπερ δηλοῦσιν αἱ τῶν ἰατρῶν
σικύαι καὶ πάνθ’ ὅσα στεγανὰ καὶ κοῖλα περιτεθέντα τῆς <τε> διαπνοῆς
αὐτὰςεἴρξαντα ῥᾳδίως κατασβέννυσιν. ἂν τοίνυν εὑρεθῇ, τί ποτε φλόγες ἐν
ταῖς τοιαύταις διαθέσεσι πάσχουσαι σβέννυνται, τάχα ἂνεὑρεθείη, τί
ποτέ ἐστιν ὃ παρὰ τῆς ἀναπνοῆς ἀπολαύει χρηστὸν ἡἐντοῖςζῴοις
θερμασία.
For these we clearly see perishing when they are deprived of air, just as
quickly as animals; as is shown by the cupping instruments of medical men,
and by all closed and hollow vessels, which readily extinguish the flames
when, placed about them, they cut them off from the draught. If it could be
discovered what happens to flames in these circumstances to quench them,
it would perhaps be discovered/what that useful something is in breathing,
from which the natural heat in animals profits.
This is a striking passage, primarily because Galen puts a finger on the
exact issue at stake. The reason why a covered flame goes out and the
reason why animals die when deprived of breath is the same from a
This is the view of Diocles and Philiston, described at the beginning of the treatise.
Ut. Resp. . ( Furley and Wilkie¼.–K).
He launches an attack on unnamed doctors who maintain that the body always requires chilling
from breathing but to a different extent. This stance, however, is dismissed on the grounds of
methodological inconsistencies rendering the position hard to evaluate. The contradiction is as
follows: commenting on the Hippocratic saying from Prognostics that the cold breathed out of the
nose and mouth is fatal, these doctors end up concluding that, in certain chilled conditions,
breathing is not necessary at all (Ut. Resp. . ( Furley and Wilkie¼.K)). Instead,
breathing kindles by fanning, which, Galen points out, is a different kind of action altogether
(Ut. Resp. . ( Furley and Wilkie¼.–K)).
To be more elaborate, it is the thermal balance in the krasis brought about by the regulating
qualitative change, as the discussion in this section shows.
Ut. Resp. . ( Furley and Wilkie¼.–K), tr. Furley and Wilkie (: ).
. The Vital Pneuma and the Purpose of Breathing
biochemical point of view. Although Galen could not possibly have known
the precise details, the process of combustion in a candle and respiration in
an organism’s cell starts when fuel (let us say, a piece of wood and glucose,
respectively) reacts with oxygen, releasing by-products (thermal heat, light
and water in combustion, and water, carbon dioxide and energy in the
case of respiration). The deprivation of oxygen naturally stops both
chemical reactions.
As Galen does not explain explicitly how he conceives the similarities of
the two processes, one might be justified in concluding that this analogy is
just a lucky accident. And indeed, any doctor in antiquity would have
lacked the means to explain the biochemical reaction. It is nonetheless
hard to deny the easy observability of the fact that healthy animal bodies
are warm, while ill or dead bodies are cold, and the loss of breath (and
nutriment) leads to the latter state. Thus, a conjecture that there is a
process in animal bodies analogous to the burning of a flame is likely based
on observation.
Galen, moreover, theorises the nature of the ‘burning’ process in the
human body on the basis of various empirical observations. Using this
method, he argues that respiration must both kindle and extinguish the
warmth in the body, the innate heat. He starts by listing the ways in which
flames can be extinguished,
including baths, excessive fanning, too much
stuff heaped onto them or the lack of sustenance. In order to continue, the
innate heat must not be increased to an extreme degree, nor must it be
cooled by fanning, nor deprived of sustenance. These conditions are
ensured by the two-fold motions, just like the motion of flame that moves
not only upwards but also downwards, for sustenance.
It is destroyed
when it is deprived of matter or one of its motions. For this reason,
he concludes, every flame requires its surroundings to be cold in due
proportion,
because excessive heat or cold quenches it.
See Debru (: –) for the relevant Aristotelian background and the argument that Galen’s
model is more fleshed out.
Ut. Resp. . (– Furley and Wilkie¼.–K).
The ‘due proportion’ is generally an important concept in ancient physiology, even if it might strike
the modern eye as vague. See San. Tu. ..– Koch (.–K), where Galen claims that all
medical sects agree that health is summetria of some kind, even though they disagree of what exactly.
The influx and the outflux of food and air are the central processes that any medical theory had to
explain. See Debru (: –) for a discussion of how the term is used in the preceding
medical tradition.
Although he meant to discuss the phenomenon of flames only at this point, Galen gets ahead of
himself and also adds that the cupping instrument is one of the ways of making the inward motion
of the flame excessive by preventing the air – overheated by the innate flame – from going outside.
This remark foreshadows the explanation of the cycles of the innate heat.
Respiration and Transpiration
The heat and its environment form a kind of small ecological system,
maintained for as long as there is a summetria, as certain proportionality, in
their qualities. In addition to the qualitative maintenance, there is also
nourishment. In the living beings, the innate heat is kindled from blood
(the standard nutriment).
This point is also illustrated with a lamp
analogy as follows: the heart is like the wick, the blood is like the oil and
the lungs are like the lamp cover.
Respiration both fans and cools the
innate heat to an appropriate degree, while the motion helps to empty out
the ‘smokiness’ from the ‘combustion of the blood’.
At this point, Galen
adds that this is not a science or demonstration but a persuasive account.
The main reason to choose this explanation is that its rivals are weaker and
suffer from some fatal flaws.
.. Bipartite Motions
Although the existence of the innate heat is rarely debated among the
ancient theorists, its origins are. On Tremor, Rigor, Palpitation and Spasm
presents a polemical defence of the Galenic account. While discussing
rigor, an affection of the innate heat, he contrasts two theories accounting
for the phenomenon of heat in the body. The first type of account is
The whole process of nutrition, including the crucial role of blood, is described in Nat. Fac.
.– (– Helmreich¼.–K); see also the discussion in Chapter .
He adds that breathing out serves to empty out the smoky vapour, just like in the account of
transpiration and respiration in On the Doctrines of Hippocrates and Plato.
This motion is technically transpiration, as it happens in the arteries; see the later discussion about
the differences between respiration and transpiration.
Towards the end of the treatise, he concedes that he found no conclusions that follow necessarily;
instead, his theory is based on persuasive conclusions and the fact that it has no counterexamples
(Ut. Resp. . ( Furley and Wilkie¼.K)). Then Galen provides a couple of cases that his
theory is able to explain, for example, breathing more deeply during exercise is due to the increase of
heat in those who move more vigorously (Ut. Resp. . ( Furley and Wilkie¼.K)). The
same reasons motivate the desire to breathe deeply when suffering from burning fevers (Ut. Resp.
. ( Furley and Wilkie¼.K)). In addition to these, Galen’s theory accounts for why
children breathe more deeply and rapidly. Interestingly, he notes that the theory that breathing is
the nourishment of the psychic pneuma helps to explain this phenomenon, because growing
children need more nourishment (Ut. Resp. . ( Furley and Wilkie¼.K); see also PHP
..– de Lacy (.–K)). He adds that this is a more general principle and one can find
people living in hotter climates breathing more deeply and rapidly. Similarly, those who have just
eaten or drunk breathe more deeply due to the constrained diaphragm as do pregnant women and
those who suffer from water or phlegm in the stomach, liver or spleen (Ut. Resp. . ( Furley
and Wilkie¼.K)). On Galen’s notion of the persuasive, see Chiaradonna (), who argues
that this notion derives from Empiricism, and Tieleman (forthcoming), who shows how the
academic inheritance in this use of the term underpins the concept of fallibilistic science
methodology.
Ut. Resp. . ( Furley and Wilkie¼.K).
. The Vital Pneuma and the Purpose of Breathing
atomistic, and Galen introduced it polemically, by stating that he does not
posit corpuscles and pores as the elements of the body (οὐκ ὄγκους καὶ
πόρους ἡμῶν στοιχεῖα τιθεμένων τοῦ σώματος). This statement is a clear
reference to Asclepiades, his followers and other comparable atomist
doctors,
whose account of fevers was discussed earlier in the treatise.
The theories of this kind maintain that the innate heat comes from friction
or motion.
Without delving into details, Galen introduces the second –
his own – account as follows: ‘we suppose the whole body breathing and
flowing together, the heat not acquired nor subsequent to the generation
of the animal, but itself first and original and innate. This is nothing other
than the nature and soul of life, so that you would not be wrong thinking
heat to be self-moving and constantly moving substance.’
Galen paints a clear contrast between the mechanistic and the vitalist
understanding of the human body. The innate heat is not a product of a
mechanistic process but a fundamental, primal part of animal physiology.
His point is the same as in the arguments advocating for the existence of
the innate natural capacities,
although in this case the issue at stake is not
so much capacity as the elemental quality itself. The most striking aspect is
calling the activity of this elemental quality ‘the soul’ and ‘the nature’. The
term ‘soul’ presumably ought to be understood as the spirited soul, the
crux of animal vitality. The distinguishing feature of animal life, then, is
the heat in the body. It is not, however, the only property that separates
animals from plants. The more extensive description in another passage of
the same treatise shows another way to understand the centrality of heat to
animality, that is, motion.
See Trem. Palp. (.K), where Galen not only names Asclepiades as someone who denies the
existence of the innate capacities and instead posits corpuscles and pores for explaining the origins
of fever, but also notes that Asclepiades ought not to be singled out, for there are more doctors
claiming the innate heat to be a product of a clearly identifiable mechanistic process.
Seemingly the same view is rejected in PHP .. de Lacy (.K). Here, more details are
supplied, indicating that it is the friction of the particles of pneuma in the arteries that is supposed
to produce the heat in an animal’s body.
Trem. Palp. (.K), tr. Sider and McVaugh (: ): ἀλλὰ τὸ μὲν ὅλον σῶμα σύμπνουν τε
καὶ σύῤῥουν ἡγουμένων, τὸ θερμὸνδ’ οὐκ ἐπίκτητον οὐδ’ ὕστερον τοῦἡγουμένων, τὸ θερμὸνδ’
οὐκ ἐπίκτητον οὐδ’ ὕστερον τοῦ ζώου τῆς γενέσεως, ἀλλ’ αὐτὸ πρῶτόν τε καὶἀρχέγονον καὶ
ἔμφυτον. καὶἥγε φύσις καὶἡψυχὴ οὐδὲν ἄλλο ἢ τοῦτ’ ἔστιν, ὥστ’ οὐσίαν αὐτοκίνητόν τε καὶ
ἀεικίνητον αὐτὸ νοῶνοὐκ ἂν ἁμάρτοις.
The capacities (dunameis) of the air, he explains, are just like the capacity of the numbing fish to
numb anyone who touches it. This is not an uncontroversial theory, as Galen notes that some
doctors deny that such qualities and capacities exist. Ut. Resp. . ( Furley and
Wilkie¼.–K). See also the references to Galen’s attack on Erasistratus in On the Natural
Capacities cited earlier.
Respiration and Transpiration
A key aspect of the innate heat is its motion, and this motion is
sustained by the two-fold directions. If it moved only inwards or only
outwards, it would soon extinguish itself. The motion downwards allows
the heat to gain sustenance, and thus it is kindled. Moving upwards, it
disperses in all directions, thus quenching itself.
By being at one
moment kindled, at another quenched, it persists. The underlying causes
of both motions are elemental properties. The motion upwards is due to
the inherent hot quality in the innate heat; its ability to move downwards,
meanwhile, is due to a portion of cold in its mixture. The result is a self-
sufficient cycle as follows:
κατὰ μὲντὸνπρῶτον λόγον τοῦ θερμοῦ, τοῦτ’ ἔστι αὐτοκίνητον αὐτοῦ,
καὶ τούτου μάλιστα δεῖται πρὸςτὰς ἐνεργείας· μεγάλην δ’ ὅμως αὐτῷ
χρείαν καὶ τὸ ψυχρὸν παρέχει. πέφυκε γὰρτὸ μὲν θερμὸνεἰς ὕψος αἴρεσθαι
καὶ συμπροσάγειν αὐτῷ τὴν τροφήν· εἰ δὲ μὴ τὸ ψυχρὸν ἐμποδὼν ἐγένετο,
καὶἐπὶ μήκιστον προῆκε. γίνεται δ’ ἐμποδὼντὸ ψυχρὸντῇ τοιαύτῃ τοῦ
θερμοῦ κινήσει, ὡςμὴἀπόλοιτο ἐκτεινόμενον. κίνδυνος γὰρ ὑπὸ
κουφότητος καὶ τῆςπρὸςτὸἄνω ὁρμῆς ἀποστῆναι τῶν σωμάτων αὐτό.
ἀλλὰ τὸ ψυχρὸν ἐπέχει τε καὶ κωλύει, καὶ τῆς ἄγαν ταύτης κινήσεως
ἀφαιρεῖ τὸ σφοδρόν.
Owing to the primal principle of heat, it is self-moved, and this is very
necessary for its activities; but the cold is equally of great usefulness to it as
well. For the heat is disposed by nature to rise upwards and bring together
with it nourishment, and if the cold did not come in its way, it would
escape to the greatest heights. But the cold does stand in the way of this
motion of the heat, so that it would not be destroyed by dispersing. For
there is danger of it leaving bodies due to its lightness and inclination to
move upwards. But the cold holds, hinders and reduces the strength of this
excessive motion.
This passage gives an outstandingly clear account of how elemental
properties govern the self-sustaining cycle of the innate heat. The property
of coldness allows motion downwards towards the sustenance, and the
property of hotness allows motion upwards, which, dispersing the heat,
sustains the equal temperature. At the same time, the passage confusingly
does not identify the substance (in the Stoic sense of the term) of the
innate heat. What material or tissue exactly contains the elemental
Trem. Palp. (.–K).
Trem. Palp. (.–K), tr. after Sider and McVaugh (: ). It is worth noting that the
phrase ‘kata proton logon’ is standard in Galen, and it refers to the original design and purpose of a
part set by the designing demiurge; see van der Eijk (: –). See also discussion of the notion
of a demiurge in Chapter .
. The Vital Pneuma and the Purpose of Breathing