Aristotle On Youth and Old Age,On Life and Death,On Breathing-Part 10

Democritus, however, does teach that in the breathing animalsthere is a certain result produced by respiration; he asserts thatit prevents the soul from being extruded from the body.Nevertheless, he by no means asserts that it is for this purposethat Nature so contrives it, for he, like the other physicalphilosophers, altogether fails to attain to any such explanation.His statement is that the soul and the hot element are identical,being the primary forms among the spherical particles. Hence, whenthese are being crushed together by the surrounding atmospherethrusting them out, respiration, according to his account, comes in tosuccour them. For in the air there are many of those particles whichhe calls mind and soul. Hence, when we breathe and the air enters,these enter along with it, and by their action cancel the pressure,thus preventing the expulsion of the soul which resides in the animal.This explains why life and death are bound up with the taking in andletting out of the breath; for death occurs when the compression bythe surrounding air gains the upper hand, and, the animal being unableto respire, the air from outside can no longer enter and counteractthe compression. Death is the departure of those forms owing to theexpulsive pressure exerted by the surrounding air. Death, however,occurs not by haphazard but, when natural, owing to old age, and, whenunnatural, to violence.But the reason for this and why all must die Democritus has by nomeans made clear. And yet, since evidently death occurs at one time oflife and not at another, he should have said whether the cause isexternal or internal. Neither does he assign the cause of thebeginning of respiration, nor say whether it is internal orexternal. Indeed, it is not the case that the external mindsuperintends the reinforcement; rather the origin of breathing andof the respiratory motion must be within: it is not due to pressurefrom around. It is absurd also that what surrounds should compress andat the same time by entering dilate. This then is practically histheory, and how he puts it.But if we must consider that our previous account is true, andthat respiration does not occur in every animal, we must deem thatthis explains death not universally, but only in respiring animals.Yet neither is it a good account of these even, as may clearly be seenfrom the facts and phenomena of which we all have experience. For inhot weather we grow warmer, and, having more need of respiration, wealways breathe faster. But, when the air around is cold andcontracts and solidifies the body, retardation of the breathingresults. Yet this was just the time when the external air should enterand annul the expulsive movement, whereas it is the opposite thatoccurs. For when the breath is not let out and the heat accumulatestoo much then we need to respire, and to respire we must draw in thebreath. When hot, people breathe rapidly, because they must do so inorder to cool themselves, just when the theory of Democritus wouldmake them add fire to fire.