Commentary Aristotle Physics
Book 4. Place, Void, and Time
Lecture 1
Natural science studies place
The physicist must have a knowledge of place, too, as well as of the infinite—namely, whether there is such a thing or not, and the manner of its existence and what it is, both because all suppose that things that exist are somewhere (the non-existent is nowhere—where is the goat-stag or the sphinx?)
and because “motion” in its most general and primary sense is change of place, which we call “locomotion.”
The question as to what place is presents many difficulties. An examination of all the relevant facts seems to lead to divergent conclusions.
Moreover, we have inherited nothing from previous thinkers, whether in the way of a statement of difficulties or of a solution.
The existence of place is held to be obvious from the fact of mutual replacement. Where water now is, there in turn air is present when the water has gone out as from a vessel. When, therefore, another body occupies this same place, the place is thought to be different from all the bodies that come to be in it and replace one another. What now contains air formerly contained water, such that the place or space into which and out of which they passed was clearly something different from both.
Further, the typical locomotions of the elementary natural bodies—namely, fire, earth, and the like—show not only that place is something but also that it has a certain power. Each is carried to its own place if it is not hindered, the one up, the other down. Now these are regions or kinds of place—up and down and the rest of the six directions. Nor do such distinctions (up and down, right and left, and the like) hold only in relation to us. They are not always the same in relation to us, but change with the direction in which we are turned, which is why the same thing may be both right and left, up and down, or before and behind.
But, in nature, each is distinct, taken apart by itself. It is not every chance direction that is “up,” but where fire and what is light are carried; similarly, too, “down” is not any chance direction, but where what has weight and what is made of earth are carried—the implication being that these places do not differ merely in relative position, but also as possessing distinct potencies. This is made plain also by the objects studied by mathematics.
Though they have no real place, they nevertheless, in respect of their position relative to us, have a right and left as attributes ascribed to them only in consequence of their relative position, not having by nature these various characteristics.
Again, the theory that the void exists involves the existence of place, for one would define void as place bereft of body. These considerations, then, would lead us to suppose that place is something distinct from bodies, and that every sensible body is in place.
Hesiod also might be held to have given a correct account of it when he made chaos first. At least he says: “First of all things came chaos to being, then broad-breasted earth,” implying that things need to have space first, because he thought, with most people, that everything is somewhere and in place. If this is its nature, the potency of place must be a marvelous thing, and take precedence over all other things. For that without which nothing else can exist, while it can exist without the others, must needs be first; for place does not pass out of existence when the things in it are annihilated.
406. After treating in book 3 of motion and the infinite, which belongs intrinsically to motion insofar as it is in the genus of continuous things, the Philosopher now intends, in book 4, to deal with the things that are extrinsically connected with motion:
first, of things that are connected with motion extrinsically as measures of mobile things;
second, of time, which is the measure of motion itself, at “next for discussion” (217b29; [558]).
As to the first, he does two things:
first, he studies place;
second, the void, at “the investigation” (213a11; [494]).
About the first, he does two things:
first, he shows that it is the business of the natural philosopher to study place;
second, he carries out his proposition, at “the existence of place” (208b1; [410]).
As to the first, he does two things.
First (208a27), he proposes what he intends and says that, just as it is the business of the natural philosopher to determine about the infinite (namely, whether it exists or not, and how it exists, and what it is), so also about place.
Second, at “both because all suppose” (208a29; [407]), he proves what he had said:
first, from the viewpoint of place itself;
second, from our viewpoint, at the question (208a32; [409]).
407. About the first, he gives two reasons, of which the following is the first (208a29). Whatever things are common to all natural things pertain especially to the considerations of the natural philosopher. But place is such, for all generally maintain that whatever exists is in some place. They prove it by a sophistic argument consisting of positing the consequent. They argue thus: what does not exist is nowhere, in no place, for there is no place where the goat-stag or the sphinx exist (these are certain fictions after the manner of chimeras). They therefore argue that, if what is found in no place does not exist, then whatever exists is in a place.
But, if to be in place belongs to all beings, it seems that place pertains to the consideration of metaphysics rather than to that of physics. And it must be said that Aristotle here argues from the opinion of those who posit that all beings are sensible, on account of their inability to go beyond their imaginations. According to them, natural science is first philosophy, common to all beings, as is mentioned in Metaphysics 4.
408. Then he gives the second reason, at and because “motion” (208a31). The consideration of motion belongs to the natural philosopher, but the motion that is according to place and is called “change of place” is the most general of all motions. For something—namely, the heavenly bodies—are moved solely according to this motion, and nothing is moved with other motions without being moved by this one. Moreover, this motion is more properly motion because it alone is truly continuous and perfect, as will be proved in book 8. But motion according to place cannot be known without knowing place. The natural philosopher, therefore, should consider place.
409. Then, at the question (208a32), he arrives at the same conclusion from our viewpoint. Wise men should settle matters about which there is doubt, and there are many doubts about what place is. There are two causes of these doubts.
One is based on place itself, because not all the properties of place lead to the same opinion about place, but from certain properties of place, it seems that place is one thing, while from other properties, that it is something else.
The other cause is based on men, for the ancients neither proposed their doubts about place well nor pursued the truth of the matter well.
410. Then, at “the existence of place” (208b1), he begins to determine about place.
First, in a dialectical manner;
second, by determining the truth, at “the next step” (210a14; [434]).
As to the first, he does two things:
first, he discusses dialectically whether place exists;
second, what it is, at “we may distinguish” (209a31; [422]).
About the first he does two things:
first, he gives reasons showing that place exists;
second, those showing that it does not exist, at but, even if (209a2; [415]).
As to the first, he does two things:
first, he shows that place exists, by using reasons based on the truth of things;
second, by reasons based on the opinions of others, at “again, the theory” (208b25; [413]).
411. In regard to the first, he gives two reasons.
In the first of these, he proceeds thus. It is clear that place is something from the very changing of bodies that are moved according to place. For just as the change that is according to form led men to the knowledge of matter, because there had to be a subject in which the forms could succeed one another, so change according to place led men to a knowledge of place, for there had to be something where bodies could succeed one another. And this is what he adds: when water goes out from where it now is, such as from some vessel, air re-enters. Since, therefore, another body sometimes occupies the same place, it is clear that place is something different from the things that are in place and that are changed according to place. For where air now is, there was previously water, and this would not be if place were not something different from both the air and the water. Consequently, place is something: it is a sort of receptacle distinct from any of the things located in it, and it is the term “from which” and “unto which” of local motion.
412. He gives the second reason at “further, the typical locomotions” (208b8), saying that, since the motion of any body whatsoever shows that place exists, as has been said, then the local motion of natural simple bodies—such as fire, earth, and similar heavy and light bodies—shows not only that place is something but also that place has a certain power and force. For we observe that each of these bodies is carried to its proper place when it is not prevented—the heavy are carried down and the light upward. This shows that place has a certain power of preserving the thing that is in place. For this reason, an object tends to its own place by a desire of self-preservation. This, however, does not prove that place has the power to attract, except in the sense in which the end is said to attract.
Up and down and the other six directions, namely, before, behind, right, and left, are the parts and species of place. These directions are determined in the universe according to nature and not merely in relation to ourselves. This is clear from the fact that, when we speak of them in relation to ourselves, the same thing is not always up or down or right or left, but varies according to our various relations to it. Hence, it frequently happens that an immobile object that was on the right comes to be on the left. The same is true of the other directions, depending on our different relations to them. But, in nature, there is a definite up and down according to the motion of heavy and light bodies, and the other directions are determined by the motions of the heavens, as was said in book 3. It is not just any part of the universe that is up and just any part that is down, but up is always where light bodies are carried and down is where heavy bodies tend. Now whatever things have according to themselves definite positions must have powers by which they are determined, for in an animal, the power of the right is distinct from the power of the left. Accordingly, place exists and has definite powers.
Now, it is shown in mathematical objects that, in certain things, the position is assigned only in relation to us; these, although they are not in place, still have a position attributed to them solely in relation to ourselves. Hence, they have no position according to nature but only according to the intellect, inasmuch as they are understood in some relation to ourselves, either as above or below, or to the right or left.
413. Then, at “again, the theory” (208b25), he appeals to the opinions of others to show that place exists.
He appeals first to the opinion of those who posit a void. For whoever asserts that the void exists must admit that place exists, since the void is nothing more than a place devoid of body. And, so, from this and from the reasons given above, it is possible to conceive that place is something other than bodies and that all sensible bodies exist in place.
414. Second, at “Hesiod also” (208b29), to confirm the same point, he uses the opinion of Hesiod, who was one of the ancient theological poets. It was he who taught that the first thing made was chaos. For he said that the first of all things made was chaos, it being a sort of confusion and a receptacle for bodies. Later, the extended earth was made to receive various bodies—as if a receptacle of things had to exist first before the things themselves could exist. And he and others posited this because, with many others, they believed that all things that exist are in place. And, if this is true, it follows not only that place exists but also that it has a remarkable power in that it is the first of all beings. For that seems to be first that can exist without other things but not they without it. But, according to them, place can exist without bodies—a conjecture they made by observing that place remains even when the things occupying it are destroyed. But things cannot exist without place. It follows, therefore, according to them, that place is the first among all beings.