
On The Heavens
therefore impossible, and the same reasoning applies also to
infinite lightness. Bodies then of infinite weight and of infinite
lightness are equally impossible.
That there is no infinite body may be shown, as we have shown it, by
a detailed consideration of the various cases. But it may also be
shown universally, not only by such reasoning as we advanced in our
discussion of principles (though in that passage we have already
determined universally the sense in which the existence of an infinite
is to be asserted or denied), but also suitably to our present purpose
in the following way. That will lead us to a further question. Even if
the total mass is not infinite, it may yet be great enough to admit
a plurality of universes. The question might possibly be raised
whether there is any obstacle to our believing that there are other
universes composed on the pattern of our own, more than one, though
stopping short of infinity. First, however, let us treat of the
infinite universally.
7
Every body must necessarily be either finite or infinite, and if
infinite, either of similar or of dissimilar parts. If its parts are
dissimilar, they must represent either a finite or an infinite
number of kinds. That the kinds cannot be infinite is evident, if
our original presuppositions remain unchallenged. For the primary
movements being finite in number, the kinds of simple body are
necessarily also finite, since the movement of a simple body is
simple, and the simple movements are finite, and every natural body
must always have its proper motion. Now if the infinite body is to
be composed of a finite number of kinds, then each of its parts must
necessarily be infinite in quantity, that is to say, the water,
fire, &c., which compose it. But this is impossible, because, as we
have already shown, infinite weight and lightness do not exist.
