Physics   

infinitum.
(6) Again, just as every body is in place, so, too, every place has a
body in it. What then shall we say about growing things? It follows
from these premisses that their place must grow with them, if their
place is neither less nor greater than they are.
By asking these questions, then, we must raise the whole problem about
place-not only as to what it is, but even whether there is such a
thing.
Part 2
We may distinguish generally between predicating B of A because it (A)
is itself, and because it is something else; and particularly between
place which is common and in which all bodies are, and the special
place occupied primarily by each. I mean, for instance, that you are
now in the heavens because you are in the air and it is in the
heavens; and you are in the air because you are on the earth; and
similarly on the earth because you are in this place which contains no
more than you.
Now if place is what primarily contains each body, it would be a
limit, so that the place would be the form or shape of each body by
which the magnitude or the matter of the magnitude is defined: for
this is the limit of each body.
If, then, we look at the question in this way the place of a thing is
its form. But, if we regard the place as the extension of the
magnitude, it is the matter. For this is different from the magnitude:
it is what is contained and defined by the form, as by a bounding
plane. Matter or the indeterminate is of this nature; when the
boundary and attributes of a sphere are taken away, nothing but the
matter is left.
This is why Plato in the Timaeus says that matter and space are the
same; for the 'participant' and space are identical. (It is true,
indeed, that the account he gives there of the 'participant' is
different from what he says in his so-called 'unwritten teaching'.
Nevertheless, he did identify place and space.) I mention Plato
because, while all hold place to be something, he alone tried to say
what it is.
In view of these facts we should naturally expect to find difficulty
in determining what place is, if indeed it is one of these two things,
matter or form. They demand a very close scrutiny, especially as it is
not easy to recognize them apart.
But it is at any rate not difficult to see that place cannot be either
of them. The form and the matter are not separate from the thing,
whereas the place can be separated. As we pointed out, where air was,
water in turn comes to be, the one replacing the other; and similarly
with other bodies. Hence the place of a thing is neither a part nor a
state of it, but is separable from it. For place is supposed to be
something like a vessel-the vessel being a transportable place. But
the vessel is no part of the thing.
In so far then as it is separable from the thing, it is not the form:
qua containing, it is different from the matter.
Also it is held that what is anywhere is both itself something and
that there is a different thing outside it. (Plato of course, if we
may digress, ought to tell us why the form and the numbers are not in
place, if 'what participates' is place-whether what participates is
the Great and the Small or the matter, as he called it in writing in
the Timaeus.)
Further, how could a body be carried to its own place, if place was
the matter or the form? It is impossible that what has no reference to
motion or the distinction of up and down can be place. So place must
be looked for among things which have these characteristics.
If the place is in the thing (it must be if it is either shape or
matter) place will have a place: for both the form and the
indeterminate undergo change and motion along with the thing, and are
not always in the same place, but are where the thing is. Hence the
place will have a place.