Physics   

and that which it receives, namely (if wine) wine, will be in it.
Obviously then a thing cannot be in itself primarily.
Zeno's problem-that if Place is something it must be in something-is
not difficult to solve. There is nothing to prevent the first place
from being 'in' something else-not indeed in that as 'in' place, but
as health is 'in' the hot as a positive determination of it or as the
hot is 'in' body as an affection. So we escape the infinite regress.
Another thing is plain: since the vessel is no part of what is in it
(what contains in the strict sense is different from what is
contained), place could not be either the matter or the form of the
thing contained, but must different-for the latter, both the matter
and the shape, are parts of what is contained.
This then may serve as a critical statement of the difficulties
involved.
Part 4
What then after all is place? The answer to this question may be
elucidated as follows.
Let us take for granted about it the various characteristics which are
supposed correctly to belong to it essentially. We assume then-
(1) Place is what contains that of which it is the place.
(2) Place is no part of the thing.
(3) The immediate place of a thing is neither less nor greater than
the thing.
(4) Place can be left behind by the thing and is separable. In
addition:
(5) All place admits of the distinction of up and down, and each of
the bodies is naturally carried to its appropriate place and rests
there, and this makes the place either up or down.
Having laid these foundations, we must complete the theory. We ought
to try to make our investigation such as will render an account of
place, and will not only solve the difficulties connected with it, but
will also show that the attributes supposed to belong to it do really
belong to it, and further will make clear the cause of the trouble and
of the difficulties about it. Such is the most satisfactory kind of
exposition.
First then we must understand that place would not have been thought
of, if there had not been a special kind of motion, namely that with
respect to place. It is chiefly for this reason that we suppose the
heaven also to be in place, because it is in constant movement. Of
this kind of change there are two species-locomotion on the one hand
and, on the other, increase and diminution. For these too involve
variation of place: what was then in this place has now in turn
changed to what is larger or smaller.
Again, when we say a thing is 'moved', the predicate either (1)
belongs to it actually, in virtue of its own nature, or (2) in virtue
of something conjoined with it. In the latter case it may be either
(a) something which by its own nature is capable of being moved, e.g.
the parts of the body or the nail in the ship, or (b) something which
is not in itself capable of being moved, but is always moved through
its conjunction with something else, as 'whiteness' or 'science'.
These have changed their place only because the subjects to which they
belong do so.
We say that a thing is in the world, in the sense of in place, because
it is in the air, and the air is in the world; and when we say it is
in the air, we do not mean it is in every part of the air, but that it
is in the air because of the outer surface of the air which surrounds
it; for if all the air were its place, the place of a thing would not
be equal to the thing-which it is supposed to be, and which the
primary place in which a thing is actually is.
When what surrounds, then, is not separate from the thing, but is in
continuity with it, the thing is said to be in what surrounds it, not
in the sense of in place, but as a part in a whole. But when the thing
is separate and in contact, it is immediately 'in' the inner surface
of the surrounding body, and this surface is neither a part of what is