If then a body has another body outside it and containing it, it
is in place, and if not, not. That is why, even if there were to be
water which had not a container, the parts of it, on the one hand,
will be moved (for one part is contained in another), while, on the
other hand, the whole will be moved in one sense, but not in
another. For as a whole it does not simultaneously change its place,
though it will be moved in a circle: for this place is the place of
its parts. (Some things are moved, not up and down, but in a circle;
others up and down, such things namely as admit of condensation and
rarefaction.)

    As was explained, some things are potentially in place, others
actually. So, when you have a homogeneous substance which is
continuous, the parts are potentially in place: when the parts are
separated, but in contact, like a heap, they are actually in place.

    Again, (1) some things are per se in place, namely every body
which is movable either by way of locomotion or by way of increase
is per se somewhere, but the heaven, as has been said, is not anywhere
as a whole, nor in any place, if at least, as we must suppose, no body
contains it. On the line on which it is moved, its parts have place:
for each is contiguous the next.

    But (2) other things are in place indirectly, through something
conjoined with them, as the soul and the heaven. The latter is, in a
way, in place, for all its parts are: for on the orb one part contains
another. That is why the upper part is moved in a circle, while the
All is not anywhere. For what is somewhere is itself something, and
there must be alongside it some other thing wherein it is and which
contains it. But alongside the All or the Whole there is nothing
outside the All, and for this reason all things are in the heaven; for
the heaven, we may say, is the All. Yet their place is not the same as
the heaven. It is part of it, the innermost part of it, which is in
contact with the movable body; and for this reason the earth is in
water, and this in the air, and the air in the aether, and the
aether in heaven, but we cannot go on and say that the heaven is in
anything else.

    It is clear, too, from these considerations that all the problems
which were raised about place will be solved when it is explained in
this way:

    (1) There is no necessity that the place should grow with the body
in it,

    (2) Nor that a point should have a place,

    (3) Nor that two bodies should be in the same place,

    (4) Nor that place should be a corporeal interval: for what is
between the boundaries of the place is any body which may chance to be
there, not an interval in body.

    Further, (5) place is also somewhere, not in the sense of being in a
place, but as the limit is in the limited; for not everything that
is is in place, but only movable body.

    Also (6) it is reasonable that each kind of body should be carried
to its own place. For a body which is next in the series and in
contact (not by compulsion) is akin, and bodies which are united do
not affect each other, while those which are in contact interact on
each other.

    Nor (7) is it without reason that each should remain naturally in
its proper place. For this part has the same relation to its place, as
a separable part to its whole, as when one moves a part of water or
air: so, too, air is related to water, for the one is like matter, the
other form-water is the matter of air, air as it were the actuality of
water, for water is potentially air, while air is potentially water,
though in another way.

    These distinctions will be drawn more carefully later. On the
present occasion it was necessary to refer to them: what has now
been stated obscurely will then be made more clear. If the matter
and the fulfilment are the same thing (for water is both, the one
potentially, the other completely), water will be related to air in
a way as part to whole. That is why these have contact: it is
organic union when both become actually one.

    This concludes my account of place-both of its existence and of
its nature.