LECTURE 8 (212 b 23-213 a 10)

FROM THE GIVEN DEFINITION OF PLACE THE DIFFICULTIES RAISED IN LECTURE 2 ARE SOLVED, AND THE NATURE OF THE PROPERTIES OF PLACE IS ESTABLISHED

             487. After the Philosopher has shown what place is, here from the given definition he answers the difficulties about place which were raised above.

             Six arguments were given above to show that place does not exist. He omits two of these; namely, the argument in which it was asked whether place is an element or composed of elements, and the argument in which it was shown that place is not reduced to any genus of cause. For those who posit place do not posit it as an element or cause of things. Hence he makes mention only of the four remaining arguments.

             488. The first of these was that, since place is not absent from body nor is body absent from place, then it seems to follow that when a body is increased the place is increased.

             But this follows on the supposition that place is a certain space coextensive with the dimensions of the body. Thus when the body grows, that space is understood to grow. But this is not necessary according to the given definition of place, which is the terminus of the container.

             489. Another argument was that if the place of a body is other than the body, then also the place of a point is other than the point. Hence it does not seem possible that place is other than the body, for the place of a point is not other than the point.

             But this argument proceeds according to the imagination of those who think that place is a space equal to the dimensions of the body. Hence it would be necessary for a dimension of space to correspond to each dimension of the body, and likewise to each point of the body. But this need not be said if we hold that place is the terminus of the container.

             490. Another argument was that if place is something it must be a body because it has three dimensions. And thus it would follow that two bodies are in the same place.

             But, according to those who hold that place is the terminus of the containing body, it need not be said that two bodies are in the same place, nor that there is any intermediate corporeal space between the extremities of the containing body. Rather some body is there.

             491. Another argument was that if everything that is is in place, it would follow that even place is in place.

             This argument is easily solved on the supposition that place is the terminus of the container. For according to this it is clear that place is in something, that is, in the containing body, not as in a place but as the terminus in some finite thing, as a point is in a line and as a surface is in a body. For it is not necessary that everything which is is in something as in a place. This is necessary only for mobile bodies. For motion leads one to distinguish between place and that which is located.

             492. Next where he says, 'Also it is reasonable . . .' (212 b 29), he establishes from the given definition the nature [ratio] of the properties of place. He shows first that a body is naturally carried to its proper place, and secondly, where he says, 'Nor is it without reason . . .' (212 b 34), that a body naturally remains in its own place.

             He says, therefore, first that if place is said to be the terminus of the container, then the cause of each body being carried to its proper place can be reasonably established. For the containing body, to which the contained and located body is consequently related and which is touched by the contained body since their termini exist together, is next to the contained body by nature and not by violence. Now the order of site in the parts of the universe is established according to the order of nature. For that celestial body which is the highest is the most noble. After this according to the nobility of nature among other bodies is fire, and so forth down to earth. Hence it is clear that an inferior body, which is consequently related according to site to a superior body, is next to it in the order of nature. Therefore he adds 'not by force' to designate the natural order of site to which the order of natures corresponds. He excludes a violent order of site, as when a terrestrial body is above air or water through violence. And two bodies, which follow each other in the natural order of site and which are established as naturally together in the order of natures, are inactive, i.e., when they are continuous to each other and become one, for which they have an aptitude because of their closeness of nature, then they are inactive. But when distinct existents touch, they are active and passive toward each other because of the opposition of active and passive qualities. Therefore the proximity of nature between the containing and contained body is the reason why a body is naturally moved to its own place. For it is necessary that the gradation of natural places corresponds to the gradation of natures, as was said. But this reason cannot be used if place is space. For in separated dimensions of space no order of nature can be considered.

             493. Next where he says, 'Nor is it without reason . . .' (212 b 34), he establishes the cause of bodies being naturally at rest in their own places.

             He says that this happens reasonably if we hold that place is the terminus of the containing body. For according to this a located body is related to the containing body as a part to a whole, although it is divided. This appears more clearly in bodies which are easily divided, like air or water, whose parts can be moved by something in the whole, as that which is located is moved in place. And this is true not only as an example of containing one thing under another, but also as a property of nature. For air is related to water as a whole, since water is as matter and air as form. For water is, as it were, the matter of air, and air is as its form. This is apparent because water is in potency to air simply.

             But it is true that air also is in a certain way in potency to water, as will be determined later in De Generatione et Corruptione. At the present time it is necessary to accept this in order to explain his position. This is not stated with certitude here, but in De Generatione et Corruptione it will be more certainly stated. For there it will be said that, when air is generated from water, the corruption is accidental and the generation is simple, because a more perfect form is introduced and a more imperfect form is abandoned. But when water is generated from air, the corruption is simple and the generation is accidental, because a more perfect form is abandoned and a more imperfect form is introduced. Therefore water is simply in potency to air, as imperfect to perfect, but air is in potency to water as perfect to imperfect. Hence air is related as a form and as a whole, which has the nature [ratio] of a form. But water is related as matter and as a part, which pertains to the nature [ratio] of matter. Therefore, although the same thing is both matter and act, since water contains both in itself, nevertheless, the one, that is, the water as imperfect, is in potency properly speaking, and the other, that is, the air, is in act as perfect. Hence water will be related to air in a certain way as a part to a whole. Therefore, when air and water are two distinct things, they touch. But when one thing comes to be from either of them by one changing into the nature of the other, then a union or continuity comes to be. Thus a part is naturally at rest in a whole, as also a body is at rest in its own natural place.

             Nevertheless it must be realized that the Philosopher is here speaking of bodies in respect to their substantial forms, which they have from the influence of a celestial body, which is the first place and which gives locating power to all other bodies. But in respect to active and passive qualities, there is opposition among the elements, and one is corruptive of another.

             Finally he concludes that the questions of whether place is and what it is have been treated.