Lecture 3 — Democritus, the Pythagoreans, and Anaxagoras

Our inquiry must begin with a statement of what seems most to belong by nature to the soul. The ensouled being would appear to differ from the non-souled being mostly in two respects: by motion and by sensation. And these two notions are roughly what our predecessors have handed down to us concerning the soul.

For some say that the soul is principally and primarily what is moving. Holding that what is not itself in motion cannot move anything else, they thought that the soul in this way is one of the things that move.

Hence Democritus said it was a kind of fire or heat. For there exist an infinity of shapes and atoms, and those of spherical form are, he said, fire and soul, like the tiny motes in the air seen in the rays of the sun in doorways, and all the seeds of these, he said, are the elements of all nature.

Leucippus had a similar opinion. Those round in shape are the soul because such shapes are most able to penetrate everywhere and to move things when they themselves also move; they are thinking that the soul is effecting the movement within the animals. This is also why breathing is coterminous with living.

For that which envelops all bodies expels by compression the shapes within, thus causing movement in animals, for these atoms are never at rest. A reinforcement must come therefore, he said, from things without by their entering in through respiration; for they prevent from dispersal those that are within the animals, and they simultaneously resist the constraining and compressing environment; and they live so long as they can do this.

The teaching of the Pythagoreans seems to mean much the same. For some of these said the soul is the particles in the air; others said it is what sets these in motion. And these are spoken of because they seem to be always moving, even if there is great tranquility.

All who say that the soul is a thing that moves itself tend in the same direction. But all seem to hold that movement is what is most proper to the soul, and accordingly, that all things are in motion on account of the soul, but the soul moves by itself on its own account, because one sees nothing moving other things that is not itself moving.

Anaxagoras likewise said that the soul is a mover, as also did anyone else who held that intellect moves all things. But his view is not at all like Democritus’s view.

For he asserts that intellect and soul are simply the same thing. For the true is what appears; this is why Homer aptly says of Hector that he lay ‘other-minded’. He does not use ‘intellect’ to denote a power that is concerned with the truth, but says that the soul and the intellect are the same thing.

But Anaxagoras is less definite about this. For he often says that the cause of being right or good is intellect, but in some places he says that this intellect is the soul. For it is in all animals, great and small, noble and base.

It does not seem, however, that there exists intellect, in the sense of prudence, alike in all animals, nor even in all men.

All those, therefore, who have regarded the ensouled from the point of view of movement have held soul to be what most causes movement.

31. Our inquiry must begin (403b24). So much by way of introduction, in which the Philosopher has stated his aim, what must be treated, and the difficulty of the undertaking; this he now proceeds to carry out in the order already indicated.

The whole treatise divides into two parts.

In the first, the soul’s nature is discussed as other philosophers have regarded it;

but in the second, as it is in truth. The latter section begins at Book 2.

The first part itself has two parts.

The former relates the opinions of other philosophers about the soul;

the second, beginning at the first thing to be considered (405b31; [68]), examines them.

The former part itself divides into two parts.

In the first, he shows the starting points of other philosophers in investigating the soul;

in the second, starting at hence Democritus said (403b31; [34]), he shows how they severally came to hold their different opinions.

32. First of all, then, he says that to start off our inquiry, we must gather together everything that seems most to belong by nature to the soul (403b24). As to this, we should note that when we find things differing both by a clear difference and by an unclear difference, it is certain that we come to know what is unclear by what is clear. This was the method used by the philosophers for discovering the nature of the soul. For ensouled things differ from non-souled in having souls; but because the nature of the soul was not evident and could not be investigated except by way of certain more obvious things that differentiate ensouled from non-souled things, the philosophers first took these more evident characteristics and tried, through them, to come to knowledge of the soul’s nature.

These evident notes are two: sensation and movement. For ensouled things seem to differ from non-souled ones mostly by motion, in that they move themselves, and by sensation, or knowledge. So the ancients thought that if they could discover the principles of these two things they would know what the soul is; hence they labored to discern the cause of movement and sensation so that thereby they might know the nature of the soul; for they believed that what is the cause of motion and sensation would be the soul. And in this all the ancient philosophers agreed.

But starting from here also the ancients became divided in their opinions; for some tried to arrive at knowledge of the soul by way of movement, and others, by way of sensation.

33. Hence at for some say (403b28), he states these differences:

and first, of those who started their inquiry from movement;

second, at all who have considered (404b8; [43]), of those who started from knowledge or sensation;

and third, at but since the soul (404b27; [52]), of those who started from both.

With regard to the first group, we should note that for those who sought the soul’s nature from motion there was one principle in common, namely, that if ensouled things are moving things, the soul must be moving. They assumed this because they thought that what is not itself in motion cannot move anything else; that is, nothing moves a thing unless it is itself moved. So if the soul moves the ensouled and nothing moves another unless it too is moving, then clearly the soul is moving most of all. It was this that led the early students of nature to judge the soul as one of the things that move.

But about this also different opinions arose.

34. When, therefore, he says, hence Democritus (403b31), Aristotle states first of all the view of Democritus, one of the early philosophers, who, thinking that the soul by nature was in a state of maximum movement, which state seems natural to fire, said that the soul was a kind of fire or heat. Such was his view. For he did not admit the existence of anything in nature except what is sensible and corporeal; and the first principles of all things, he said, are indivisible bodies, infinite in number, which he called atoms. These atoms, he said, are all the same by nature, differing from each other only in shape, position, and arrangement (though here, only the difference of shape is alluded to, as being the only necessary one; this consists in some being round, some square, some pyramids, and so on). He also maintained that the atoms were mobile and never ceased moving and that the world had come into being through their fortuitous coming together. And to illustrate the mobility of these bodies, he took the example of the particles that move in the air even when no wind blows, as we can see when rays of the sun are in doorways. Since the atoms, being indivisible, are much smaller than such particles, they must obviously be extremely mobile. And because the spherical is, of all shapes, the one best suited for movement—having no angles to impede it—and since the soul, as the cause of movement in living, was thought to have maximum mobility, Democritus concluded that among these infinitely numerous bodies, the spherical ones were the soul.

35. Leucippus, a companion of Democritus, held the same opinion. And Democritus thought the following was a sign of its truth. He maintained that respiration is coterminous with, or essential to, life (a short-sighted view, since not all living things breathe), and that respiration is necessary because the body is full of small ever-moving spherical particles (the cause, as he thought, of all movement in animal bodies) and that the surrounding air compresses what it envelops, that is, our bodies, and expels, that is, thrusts out of them, those particles which are so shaped as to cause movement in animals, being never at rest themselves. Lest, therefore, our bodies should decay with the loss of all these particles, he said that respiration is necessary, whereby fresh particles may be brought in and those already within prevented from leaving by those that inhaling brings in. And he said that animals can live so long as they can do this, that is, as long as they can breathe. The point of the argument is that if breathing is called the cause of life because it keeps the spherical particles inside the animal body and also introduces fresh ones lest the body should decay through loss of particles by movement, then it is clearly implied that the particles are the soul itself. They are indeed the same particles that Democritus said were fiery by nature and the cause of heat.

36. Next, at the teaching of the Pythagoreans (404a16), Aristotle mentions a view of certain Pythagoreans, which resembles that of Democritus; for their statement and his seem to mean much the same, although the Pythagoreans themselves do not all agree.

Some of them, agreeing with Democritus, said that atoms in the air, that is, indivisible, infinitely numerous particles, were the soul.

Others, however, of the same school, said that the soul was rather the force that moved those particles. Of this opinion was a certain Archelaus, the master of Socrates, as Augustine remarks in the City of God. (Augustine, City of God, bk. 8, ch. 2.) The reason why the soul has been thus identified with these particles has been already given—namely, that as the soul was regarded as being especially mobile, and as those particles seem to be always moving (even when the air is tranquil), they identified the one with the other.

37. Then, at all who say (404a20), he summarizes the views of a number of philosophers, saying that all who have defined the soul in terms of movement and called it that which moves itself, tend in the same direction, that is, the same as those mentioned already. All these seem to hold that movement is what is most proper to and the chief characteristic of the soul: all things being moved by the soul, and the soul moved by itself on its own account. The reason for this was, as has been noted, that they all thought that only what was itself moved could move other things. Since the soul moves other things, they thought the soul especially and principally was in motion.

38. In the third place, at Anaxagoras likewise (404a25), he states the view of Anaxagoras.

He first shows how this philosopher agrees with those already mentioned, saying that Anaxagoras, and anyone else who held that intellect moved all things, really agreed with them that the source of all movement was a soul. Anaxagoras, however, differed in that he denied that every mover was itself in motion; he maintained the existence of a pure and transcendent intellect which, motionless itself, moved all other things, and he maintained that the soul was of this nature too. (This view led some into the error of divinizing the soul.) Thus Anaxagoras agreed with the other philosophers in calling the soul a principle of movement, but he disagreed with them in saying that it was not itself moved (for they said the contrary).

And he also differed from Democritus in what he understood by “intellect.”

39. When Aristotle therefore says, Democritus asserts (404a27), he states this last difference.

First, he states Democritus’s opinion, saying that he (that is, Democritus) said that intellect and soul were simply, that is, everywhere and universally, the same thing.

Democritus said this because he held that only sensible things exist in the real world, and that just as nothing but sensible things exist in the world, so too, he said no cognitive power exists in the soul except the sense power. From this, he inferred that no truth about things was determinately attainable, and that nothing could be determinately known; rather, whatever appears is true, and what one man thought about anything is not more true than what another man thought about the same thing at the same time. In consequence, he maintained that contraries would be both true at the same time.

And this is because, as we have said, he did not use “intellect” as what is concerned with the truth, that is, as an intellectual power by which the soul understands intelligible objects, but as a mere sense power. Only the sensible, he thought, may be known, since only the sensible exists in the nature of things. And because sensible things are continually in motion and flux, he thought that there is no determinate truth in things.

Never attaining to an understanding of the intellect as a power concerned with the truth, that is, that whose object is the true itself and that exceeds all the other powers of the soul, admitting only the soul’s powers of sense, he says that the soul and the intellect are the same universally and without any distinction. This intellect changed, he said, as the man changed. Hence his approval of Homer’s phrase, Hector lies other-minded, that is, Hector’s mind changed insofar as he changed; for he thought one thing as conqueror, another as conquered.

40. Next, at Anaxagoras is less definite (404b1), he shows how Anaxagoras differed from Democritus.

About this he does two things:

first, stating the former’s opinion;

second, at it does not seem (404b5; [41]), criticizing it.

First, then, he observes that Anaxagoras spoke with less certainty and was less definite about this. For he often said that intellect was the cause of acting well, or good action, while in some places, he also says this intellect is the cause of good action and is the same thing as the soul.

And this is obvious, for it is certain that soul is found in all animals, the lower as well as the noble, the small as well as the great; whence, since Anaxagoras said that intellect was in all of them, clearly he identifies soul and intellect.

41. Second, at it does not seem (404b5), he shows the inconsistency of Anaxagoras’s use of the term “intellect.” For sometimes Anaxagoras distinguishes between soul and intellect, but sometimes also he identifies them. These are contrary and cannot both stand simultaneously.

And this he proceeds to show with this argument: it is certain that to act well is proper to intellect as perfected by prudence, since to act well pertains to prudence. If, then, the intellect, which causes good action, is the same as the soul, it would follow that the prudent intellect would be the same as the soul; but this is false because, while all animals have souls, intellect in the sense of prudence seems not to be present not merely in all animals, but not even in all men. Therefore it is not the same as the soul.

42. Lastly, at all those, therefore (404b7), he states that all who have regarded the soul from the standpoint of movement, that is, as self-movers, thought that the soul is what most causes movement, as the above-mentioned opinions show.