Lecture 3: On Being Alive: Aristotle

Foundations of Liberty
The Intellectual Crisis of the Modern World

A Lecture Series with Prof. Thomas Patrick Burke

The intellectual crisis of the modern world is the conflict between the physical sciences and the basic human values. Physics and chemistry, together with much of biology, have been immensely successful in giving us knowledge of the world we live in. Yet they cannot tell the difference between a human being and a rock, except incidentally. All the features of human beings that make us distinctively human—being alive, having a mind, consciousness and subjectivity, possessing free will, moral virtue and moral principle, the sense of beauty, feelings, and many other qualities—are invisible to science and do not exist for it.  For over a hundred years this contradiction has been giving us a deeply impoverished conception of ourselves and our world. Our first aim in these lectures is to trace the sequence of historical events by which this state of affairs developed. It began with Socrates.

In the first of these lectures we became acquainted with Socrates’s demand for the teleological explanation of nature, i.e. accounting for the things of nature in terms of their goals or purposes, what was good or for “the best,” rather than by purely causal explanations. In the second lecture we saw Plato’s response to that demand.  It was that the things of nature are not all alike.  Within the realm of the natural there is a very big difference between things that are alive and things that are not alive. Things that are alive have the unique power to move themselves. That is, they are by nature teleological or oriented towards a purpose. Things that are not alive do not have this power, and consequently are not teleological but mechanical. It follows from this (though Plato does not seem to have stated this explicitly) that Socrates’s advocacy of teleological explanation was correct for living beings, but not for those that are not living.

In this lecture we turn to Aristotle, Plato’s greatest pupil, himself a great scientist and the founder of several sciences including biology, whom Dante called “the teacher of those who know.” What does he make of Socrates’s demand?

Aristotle responds in two ways, both of which were to be of historic importance. Unlike Plato, he accepts Socrates’s demand for the teleological explanation of nature, not only of the living but also of the inanimate, making teleology the foundation of scientific method for almost 2000 years. But he rejects Plato’s contention that living things move themselves. He considers self-movement impossible. Not even God can move himself.  This remains the standpoint of science even today.

1. Teleology

In his treatise on Physics Aristotle observes that the aim of science (‘επιστημη) is knowledge. Men do not think they know a thing till they know the “why” of it, its causes.  For us today the word “cause” usually has only one meaning, though different accounts may be given of that meaning. A cause is what produces the effect or brings it about.  But Aristotle, as is well-known, distinguishes four different kinds of cause.  In one sense, the material a thing is made out of, such as the bronze of a statue or the silver of a bowl, is said to be a cause of it. In another sense, the form or archetype or essence or idea of it. In a third sense the primary source of the change that brought it about, the maker of it, as “the father is the cause of the child” or “the man who gave the advice” is the cause of the action. This is what we today usually call a cause. The fourth sense is that “for the sake of which” (‘ενεκα), the purpose or reason why the thing is done or made: “what is best.” (PhysicsBook 2, Ch. 3)  This is the teleological cause. If we consider a loaf of bread, the material cause is the dough and the formal cause is the nature or idea of bread. The efficient cause is the man who makes it, the baker.  The teleological cause is the reason why he bakes the bread, or the purpose of the bread: it is made to be eaten. The scientist, says Aristotle, must seek to discover all four causes of any phenomenon. But the main task is to discover the purposive or teleological cause, the goal it serves, or what is for the best. For this is the chief factor that explains the making of anything.  He states these four causes in different ways in different works.

There are four causes underlying everything: first, the teleological cause, that for the sake of which, as an end, a thing exists (το ου ενεκα ως τελος); secondly, the formal cause, the definition of its essence…; thirdly, the material cause; and fourthly, the moving principle or efficient cause. (On the generation of Animals, Bk 1.)

The causes concerned in the generation of the works of nature are, as we see, more than one. There is the final cause and there is the motor cause. Now we must decide which of these two causes comes first, which second. Plainly, however, that cause is the first which we call the final one. For this is the Reason, and the Reason forms the starting-point, alike in the works of art [intelligence] and in works of nature. For consider how the physician or how the builder sets about his work. He starts by forming for himself a definite picture, in the one case perceptible to mind, in the other to sense, of his end—the physician of health, the builder of a house—and this he holds forward as the reason and explanation of each subsequent step that he takes, and of his acting in this or that way as the case may be. Now in the works of nature the good end and the final cause is still more dominant than in works of art such as these…

(On the Parts of Animals, Bk 1,1)

Teleology Applies to All of Nature, Not Only the Animate But Also the Inanimate

Aristotle’s first principle in regard to the analysis of nature is that all of nature is inherently teleological. Nature does nothing in vain. Everything in nature exists for a purpose. This of course was what Socrates had insisted on.  Fatally, Aristotle simply agrees with Socrates, and does not draw Plato’s distinction between the living and the non-living.  Aristotle sees confirmation of his view in the fact that a distinction runs throughout nature between what is always or normally the case and what is only abnormally or unusually so.  If something is always or normally the case, that is a sign it is natural.

We must explain then …that Nature belongs to the class of causes which act for the sake of something [heneka]. (Phys. II,8)

First then we observe that some things always come to pass in the same way, and others for the most part. (Phys. II, 5)

While if something happens only abnormally or unusually, that indicates it is not natural but “violent.”  For example, he analyzes locomotion, movement in place, teleologically by distinguishing “natural motion” from “violent motion.”  Some things by nature move upwards, such as fire. This movement comes from a principle within themselves. Other things by nature move downwards, such as stones. Each has its own kind of purpose or directedness built into it, even though it is inanimate. But it is possible for an outside force to intervene.  A human being can clutch the stone and throw it up into the air. This does violence to the stone, making it go against its nature.

Like a good scientist, however, he does not merely argue in favor of his view, but considers the arguments for the other side.

But… a difficulty presents itself: why should not nature work, not for the sake of something, nor because it is better so, but just as the sky rains, not in order to make the corn grow, but of necessity? What is drawn up must become cool, and what has been cooled down must become water and descend, the result of this being that the corn grows. Similarly if a man’s crop is spoiled on the threshing-floor, the rain did not fall for the sake of this—in order that the crop might be spoiled—but that result just followed. Why then should it not be the same with the parts in nature, e.g. that our teeth should come up of necessity—the front teeth sharp, fitted for tearing, the molars broad and useful for grinding down the food—since they did not arise for this end, but it was merely a coincident result; and so with all other parts in which we suppose that there is purpose? Wherever then all the parts came about just what they would have been if they had come be for an end, such things survived, being organized spontaneously in a fitting way; whereas those which grew otherwise perished and continue to perish, as Empedocles says his ‘man-faced ox-progeny’ did.  [We see here that the theory of biological progress through the survival of the fittest, made so famous by Darwin and Spencer, was already clear to Aristotle. But he rejects it.]

Such are the arguments (and others of the kind) which may cause difficulty on this point. Yet it is impossible that this should be the true view. For teeth and all other natural things either invariably or normally come about in a given way; but of not one of the results of chance or spontaneity is this true. We do not ascribe to chance or mere coincidence the frequency of rain in winter, but frequent rain in summer we do; nor heat in the dog-days, but only if we have it in winter. If then, it is agreed that things are either the result of coincidence or for an end, and these cannot be the result of coincidence or spontaneity, it follows that they must be for an end; and that such things are all due to nature even the champions of the theory which is before us would agree. Therefore action for an end is present in things which come to be and are by nature.

Further, where a series has a completion, all the preceding steps are for the sake of that. Now surely as in intelligent action, so in nature; and as in nature, so it is in each action, if nothing interferes. Now intelligent action is for the sake of an end; therefore the nature of things also is so. Thus if a house, e.g. had been a thing made by nature, it would have been made in the same way as it is now by art; and if things made by nature were made also by art, they would come to be in the same way as by nature. Each step then in the series is for the sake of the next; and generally art partly completes what nature cannot bring to a finish, and partly imitates her. If, therefore, artificial products are for the sake of an end, so clearly also are natural products. The relation of the later to the earlier terms of the series is the same in both. This is most obvious in the animals other than man: they make things neither by art nor after inquiry or deliberation. Wherefore people discuss whether it is by intelligence or by some other faculty that these creatures work, spiders, ants, and the like. By gradual advance in this direction we come to see clearly that in plants too that is produced which is conducive to the end—leaves, e.g. grow to provide shade for the fruit. If then it is both by nature and for an end that the swallow makes its nest and the spider its web, and plants grow leaves for the sake of the fruit and send their roots down (not up) for the sake of nourishment, it is plain that this kind of cause is operative in things which come to be and are by nature.
(But what about monstrosities?)

Now mistakes come to pass even in the operations of art: the grammarian makes a mistake in writing and the doctor pours out the wrong dose. Hence clearly mistakes are possible in the operations of nature also. If then in art there are cases in which what is rightly produced serves a purpose, and if where mistakes occur there was a purpose in what was attempted, only it was not attained, so must it be also in natural products, and monstrosities will be failures in the purposive effort. Thus in the original combinations the ‘ox-progeny’ if they failed to reach a determinate end must have arisen through the corruption of some principle corresponding to what is now the seed.

Further, seed must have come into being first, and not straightway the animals…

Again, in plants too we find the relation of means to end, though the degree of organization is less. Were there then in plants also ‘olive-headed vine-progeny’, like the ‘man-headed ox-progeny’, or not? An absurd suggestion; yet there must have been, if there were such things among animals.

Moreover, [on this view] among the seeds anything must have come to be at random. But the person who asserts this entirely does away with ‘nature’ and what exists ‘by nature’. For those things are natural which, by a continuous movement originated from an internal principle, arrive at some completion: the same completion is not reached from every principle; nor any chance completion, but always the tendency in each is towards the same end, if there is no impediment.

The end and the means towards it may come about by chance. We say, for instance, that a stranger has come by chance, paid the ransom, and gone away, when he does so as if he had come for that purpose, though it was not for that that he came. This is incidental, for chance is an incidental cause, as I remarked before. But when an event takes place always or for the most part, it is not incidental or by chance. In natural products the sequence is invariable, if there is no impediment.

It is absurd to suppose that purpose is not present because we do not observe the agent deliberating. Art does not deliberate. If the ship-building art were in the wood, it would produce the same results by nature. If, therefore, purpose is present in art, it is present also in nature. The best illustration is a doctor doctoring himself: nature is like that.

It is plain then that nature is a cause, a cause that operates for a purpose.

(Physics, Book II, Chapter 8)

Although Aristotle distinguished four different kinds of cause, as we have seen, there is a close link in his mind between the form or formal cause of a thing and its teleological cause. The aim of living things is to achieve their full and proper form. The acorn wishes to become an oak. Only in the form of the mature oak tree is the true nature of the acorn realized. Thus in regard to living things it is possible to identify the formal and teleological causes. But Aristotle assumes that this applies universally, and therefore also to inanimate objects. In this, however, he was mistaken. A stone does not desire to achieve the full and proper form of a stone. Stones do not desire anything. They just are what they are.  (Aristotle’s assumption also perhaps misled Hegel.)
Aristotle’s teleology would dominate science until the arrival of Francis Bacon, Galileo and Descartes.

2.  The Impossibility of Self-Movement

We saw in previous lectures that there were thinkers in ancient Greece, such as Parmenides and Zeno, who denied the reality of change. They did this in various ways and for various reasons. Aristotle, however, accepted the reality of change and devised a philosophical theory to explain it and so justify belief in it: this is the theory of actuality and potentiality. Actuality is simply reality. Potentiality is the ability to become a reality. Let us return to the bread. Say I buy a loaf of bread, and at the same time I buy a packet of flour or dough which can become bread if I put it in the oven. The loaf of bread is actually bread. The dough, however, is only potentially bread. Change consists in the replacement of potentiality by actuality.  I put what is actually dough but potentially bread in the oven and it becomes actually bread.

This seems simple enough. But if we accept it, we will find it has surprising and far-reaching consequences indeed. For it follows from this theory that nothing can move itself. For only what is itself already actual, says Aristotle, can change a potentiality into actuality. Only something already hot can move a cold thing to become hot. Although in the individual being undergoing change itself potentiality comes before actuality, in the causal process viewed as a whole actuality must come before potentiality.  Therefore to move itself a thing would have to be both in potentiality and in actuality in the same respect at the same time; which is impossible.

How then does Aristotle explain the apparently obvious fact that living things move themselves, that dogs, for example, that been lying around doing nothing suddenly get up and look for dinner? Or we ourselves, for that matter. His explanation is that one part of the dog moves another part. The heart is already beating and that moves the legs. But what makes the heart beat? Ultimately all the motion on the earth is the result of the movement of the celestial spheres. For he envisions the earth as in the center of a series of invisible crystalline concentric spheres revolving around it, one containing the moon, then one for the sun, then one for each of the planets, and lastly, on the perimeter, the outermost sphere, the primum mobile, or first thing that is moved. This sphere is moved by God, who is the primum movens, or first thing to cause movement. But God himself is never in motion and never changes. For he is the perfect and most excellent being, as Plato had said. The sense in which God causes movement in the world is not as the efficient or productive cause of it, as the Book of Genesis suggests, but the teleological cause: he causes movement by the attractiveness of his beauty and excellence, as a magnet draws an iron bar or as a beautiful beloved attracts a lover.  This seems also to have been Dante’s God, “the love that moves the sun and the other stars” (l’amor che move il sole e le altre stelle—the last line of the Paradiso).