LECTURE 7 (212 a 31-b 22)

WHAT THINGS ARE IN PLACE SIMPLY. HOW THAT WHICH IS NOT IN PLACE SIMPLY IS IN PLACE ACCIDENTALLY

             472. After the Philosopher has defined place, he here explains how a thing is in place.

             Concerning this he makes two points. First he explains how a thing is in place simply and how not. Secondly, where he says, 'That is why . . .' (212 a 32), he explains how that which is not in place simply is in place accidentally.

             473. First, therefore, he concludes from the foregoing that, since place is the terminus of the container, then any body is in place simply and per se when it is adjacent to another body which contains it from the outside. And a body is least of all in place when it is not adjacent to another body which contains it from the outside. Moreover, there is only one such body in the world, that is, the ultimate sphere, whatever that might be. Hence according to this position it follows that the ultimate sphere is not in place.

             474. But this seems impossible. For the ultimate sphere is moved in place, but nothing which is not in place is moved in place.

             This difficulty does not arise for those who hold a belief in space. For it is not necessary for them to say that the ultimate sphere has a containing body in order for it to be in place. Rather, according to them, space, which is understood to penetrate the whole world and all its parts, is the place of the whole world and each of its parts.

             But this position is impossible. For it is necessary to say either that place is not something other than that which is located, or that there are dimensions of space which exist per se and nevertheless which enter into the dimensions of sensible bodies. Both of these are impossible.

             475. Hence Alexander said that the ultimate sphere in no way is in place. For not every body is necessarily in place, since place does not fall in the definition of body. Because of this he said that the ultimate sphere is not moved in place, either in respect to the whole or in respect to the parts.

             But because it is necessary for every motion to be in some genus of motion, Avicenna, following him, said that the motion of the ultimate sphere is not a motion in place, but a motion in site. This is contrary to Aristotle, who says in Book V of this work that there is motion in only three genera, that is, in quantity, quality, and place.

             But this position cannot stand. For it is impossible for there to be motion per se speaking in a genus the nature [ratio] of whose species consists in indivisibility. Because of this there is no motion in substance, for the nature [ratio] of each species of substance consists in indivisibility, that is, the species of substance are not said to be greater or less. And also, since motion has succession, substantial form is not produced in existence through motion but through generation, which is the terminus of motion. However, it is quite otherwise with whiteness and other similar things which are participated according to greater or less. Now each species of site has a nature consisting in indivisibility, such that if something is added or subtracted it is not the same species of site. Hence it is impossible that there be motion in the genus of site.

             And furthermore the same difficulty remains. For site, insofar as it is a predicament, involves an order of parts in place. Although insofar as site is a differentia of quantity, it does not involve anything except an order of parts in the whole. Therefore it is necessary that whatever is moved in respect to site is moved in respect to place.

             476. Moreover others have said, for example, Avempace, that the place of a body which is moved in a circle must be explained differently than the place of a body which is moved in a straight line. For since a straight line is imperfect because it receives addition, a body which is moved in a straight line requires a place which contains it from the outside. But since a circular line is perfect in itself, a body which moves in a circle does not require a place which contains it from the outside, but a place about which it revolves. Hence circular motion is also said to be motion around a middle. Thus they say that the convex surface of the contained sphere is the place of the first sphere. But this is contrary to the common suppositions about place given above, that is, place is a container and place is equal to that which is located.

             477. Therefore Averroes said that the ultimate sphere is in place accidentally.

             To understand this it must be realized that everything which is held fast by another is said to be in place accidentally due to the fact that that by which it is held fast is in place. This is clear in regard to a nail fixed in a ship, and in regard to a man at rest in the ship. Now it is clear that bodies moved in a circle are held fast by the immobility of the centre. Hence the ultimate sphere is said to be in place accidentally insofar as the centre about which it revolves exists in place. And it happens that the other inferior spheres have a place per se in which they are contained. But this is not necessarily true of bodies moved in a circle.

             But against this one can object that, if the ultimate sphere is in place accidentally, then it follows that it is moved in place accidentally. And thus motion per accidens is prior to motion per se. But to this one can respond that in regard to circular motion it is not required that that which moves per se in a circle is per se in place. However this is required for straight motion.

             But this seems to be contrary to Aristotle's definition, given above, of that which is in place accidentally. For he said that things exist or are moved in place accidentally because that in which they are is moved. But a thing is not said to be in place accidentally because something which is altogether extrinsic to it is in place. Since, therefore, the centre is altogether extrinsic to the ultimate sphere, it seems ridiculous to say that the ultimate sphere is in place accidentally because the centre is in place.

             478. Therefore I will rather approve the opinion of Themistius, who said that the ultimate sphere is in place through its parts.

             To understand this it must be realized, as Aristotle said above, that place would not be investigated if it were not for motion, which calls attention to place because bodies succeed each other in one place. Hence although a body does not of necessity have place, nevertheless, a body which is moved in respect to place does have place of necessity. Therefore, it is necessary to assign place to a body moved in place insofar as one considers in that motion a succession of diverse bodies in the same place. Thus in things which are moved in a straight line, it is clear that two bodies succeed each other in place in respect to the whole. For the whole of one body leaves the whole place and into that whole place another body enters. Hence it is necessary that a body which is moved in a straight line is in place in respect to its whole self.

             But in circular motion, although the whole comes to be in diverse places by reason [ratio], nevertheless the whole does not change place in the subject. For the place always remains the same in the subject, and it is diversified only by reason [ratio], as will be said in Book VI of this work. But the parts change place not only according to reason [ratio] but also in the subject. Therefore, in circular motion attention is directed to succession in the same place, not of whole bodies, but of parts of the same body. Hence for a body moved in a circle a place in respect to the whole is not due of necessity, but only in respect to the parts.

             479. But contrary to this it seems that the parts of a continuous body are not in place nor are they moved in respect to place. Rather the whole is moved and the whole is in place. However it is clear that the ultimate sphere is a continuous body. Therefore its parts are not in place and are not moved in respect to place. And thus it does not seem to be true that place belongs to the ultimate sphere by reason [ratio] of the parts.

             But to this it must be said that, although the parts of a continuous whole are not actually in place, nevertheless they are potentially in place insofar as the continuum is divisible. For if a part is divided, it will be in the whole as in a place. Hence in this way the parts of the continuum are moved in place. This is especially apparent in continuous liquids which are easily divided, as in water whose parts are found to be moved within the water as a whole. Therefore, since something is said of a whole by reason [ratio] of the parts, insofar as the parts of the ultimate sphere are potentially in place, the whole ultimate sphere is in place accidentally by reason [ratio] of the parts. And to be thus in place suffices for circular motion.

             480. However, one might object that that which is in act is prior to that which is in potency, and thus it seems unsuitable that the first local motion is of a body existing in place through parts, which are potentially in place. To this it must be said that this especially agrees with the first motion. For it is necessary to descend gradually from the one immobile thing to the diversity which is in mobile things. Now the variation according to parts existing potentially in place is less than that according to a whole existing actually in place. Hence the first motion, which is circular and which exists closer to the immobile substances, has less deformity and retains more uniformity. Moreover it is much more suitable to say that the ultimate sphere is in place because of its own intrinsic parts than because of the centre which is altogether outside of its substance. And this is more consonant with the opinion of Aristotle, as is clear to one who examines what follows, in which the Philosopher explains how the heavens are in place, where he says, 'That is why . . .' (212 a 32).

             481. Concerning this he makes two points. First he explains how the ultimate sphere is in place. Secondly, where he says, 'That is why the upper part . . .' (212 b 14), he infers a conclusion from what has been said.

             Concerning the first part he makes three points. First he shows that the ultimate sphere is in place through its parts. Secondly, where he says, 'As was explained . . .' (212 b 3), he explains how its parts are in place. Thirdly, where he says, 'Again, some things are . . .' (212 b 7), he explains how from the parts it belongs to the whole to be in place.

             482. He has said that that which does not have something outside containing it is not in place per se. Therefore, he concludes that if water (concerning which what he is saying is more apparent because of the easy division of its parts) is a body of such a kind that it is not contained by another, as is the ultimate sphere, then its parts will be moved insofar as they are contained under each other, thus existing in some way in place. But the water as a whole in one way will be moved and in another way not. For it will not be moved such that the whole together changes place, as if moved to another place different in subject. But it will be moved in a circle, which motion indeed requires place for the parts but not for the whole. And it will not be moved upwards and downwards, but in a circle. However certain things will be moved upwards and downwards, changing place in respect to the whole, that is, rare and dense bodies, and heavy and light bodies.

             483. Next where he says, 'As was explained . . .' (212 b 3), he explains how the parts of the ultimate sphere are in place. He says, as was said above, that certain things are actually in place and certain things are potentially in place. Hence when a thing is a continuum of similar parts, its parts are potentially in place, as is the case with the ultimate sphere. But when the parts are separated and only contiguous, as happens in a pile of stones, then the parts are actually in place.

             484. Next where he says, 'Again, some things are . . .' (212 b 7), he shows how it follows from this that the whole sphere is in place.

             He says that certain things are in place per se, as any body which is moved per se in place either by change of place or by increase, as was said above. But the heavens, that is, the ultimate sphere, is not in place in this way, as was said, since no body contains it. But insofar as it is moved in a circle, its parts succeeding each other, place belongs potentially to its parts, as was said, insofar as one of its parts is a 'habit', that is, insofar as it is consequently related to another.

             Certain things, as the soul and all forms, are in place accidentally. And in this way the heavens, that is, the ultimate sphere, also is in place, insofar as all its parts are in place because each of its parts is contained under the others by the circulation. For in a non-circular body the extreme part remains not contained but only containing. But in a circular body each part is both container and contained, although potentially. Hence by reason [ratio] of all its parts a circular body is in place. And he takes this to be accidental, that is, through the parts, as above when he said that the parts of a body are moved accidentally in place.

             485. Next where he says, 'That is why the upper part . . .' (212 b 14), he induces a certain conclusion from the foregoing.

             Since he has said that a body moved in a circle cannot be in place in respect to the whole, but only accidentally by reason [ratio] of the parts, he concludes that the highest body is moved only in a circle because that whole is not anywhere. For that which is somewhere is something and has something outside itself by which it is contained. But outside the whole there is nothing. And because of this all things are said to be in the heavens as in the ultimate container. For the heavens perhaps are the containing whole. He says 'perhaps' because it has not yet been proven that there is nothing outside the heavens. However, it must not be thought that place is the body of the heavens, but rather that place is a certain ultimate surface of the heavens toward us, and is like a terminus touching the mobile bodies which are in it. Because of this we say that earth is in water, which is in air, which is in aether, that is, fire, which is in the heavens, which is not further in another.

             486. According to Averroes this text must be explained otherwise. The example of the water, which Aristotle brings in first, must not be referred according to Averroes to the ultimate sphere, but to the whole universe, which indeed is moved insofar as its parts are moved. Certain parts, the celestial bodies, are moved in a circle, and others, the inferior bodies, are moved upwards and downwards. That which Aristotle brings in later, i.e., that certain things are actually in place and others potentially in place, must not be referred to what was previously said, but must be taken as said on its own account. For since Aristotle has said that certain things are in place in respect to the parts and others in respect to the whole, he consequently adds that certain things are actually in place and others potentially in place--and further that certain things are in place per se and others accidentally.

             Regarding this it must be noted that according to Averroes the 'heavens' is taken here in two ways. First the 'heavens' is taken to mean the universe of bodies, especially celestial bodies. Secondly the 'heavens' is taken to mean the ultimate sphere. Therefore he says that those things are per se in place which are moved in place, either in respect to the whole or to the parts, as the heavens, that is, the universe. But things like the soul or the heavens, that is, the ultimate sphere, are accidentally in place. For it is necessary to say that all the parts of the universe are in place in some way, the ultimate sphere accidentally, and other bodies per se, insofar as they are contained by an exterior body. And he maintains this constantly to the end.