Aristotle
their nature, and must be composed of the same bodies, having the
same nature and powers--fire, earth, and the two intermediate
elements: for, if the bodies here are not the same as those in other
Kosmi--if the same names are given in an equivocal sense and do not
connote the same specific attributes--the name Kosmos must be
equivocal also, and there cannot be many true or real Kosmi, in the
same sense. To the parts or elements of each Kosmos, therefore, the
centripetal and **centrifugal currents are natural; for the simple
currents are limited in number, and each element is so named as
to connote one of them specially; and, if the currents are
the same, the elements must also be the same everywhere. If there
were another Kosmos, the earth in that would tend towards the centre
of our Kosmos, and the fire in that would tend towards the periphery
of our Kosmos. But this is impossible; since in that case the earth
in that Kosmos would run away from the centre of its own Kosmos, and
the fire therein would run away from its own periphery. Either we
must not admit the same nature in the simple elements of the numerous
Kosmi; or, if we do admit it, we must recognize only one centre and
one periphery. This difficulty prevents our recognizing more than one
Kosmos (ss. 1-6).
It is unphilosophical to affirm that the nature of these simple
elements becomes changed according as they are more or less distant
from their own places. The difference is at best one of degree, not
one of kind. That they _are_ moved, we see plainly; there must
therefore be some one current of motion natural to them. Accordingly
every portion of the same element (or of elements the same in kind)
must tend towards the same numerical place--towards this actual
centre ([Greek: pro\s to/de ti me/son]), or that actual periphery;
and, if the tendency be towards one centre _specie_, but towards many
centres _numero_, because particulars differ _numero_ alone, and not
_specie_, still the attribute will be alike in all, and will not be
present in some portions, absent in others: I mean that, if the
portions of this Kosmos are relative to each other, those in another
Kosmos are in the like condition, and what is taken from this Kosmos
will not be different from what is taken from the corresponding
elements of any other Kosmos. Unless these assumptions can be
overthrown, it is indisputably certain that there can be only one
centre and one periphery; by consequence therefore, only one Kosmos
and not more (ss. 7-10).
There are other reasons to show that there is a given terminus for
the natural current both of fire and of earth. A thing moved,
speaking generally, changes from something definite into something
else definite; but there are different species of such change: the
change called getting-well is from sickness to health; that called
growth is from the little to great; that called local movement is
from a terminus to another terminus, and local movements are
specifically different from each other, according as the terminus _a
quo_ and the terminus _ad quem_ is defined in each. The terminus is
always a known and definite point: it is not accidental, nor
dependent upon the arbitrium of the mover. Fire and earth therefore
do not move on to infinity, but to definite points in opposite
directions; and the local antithesis is between above and below:
these are the two termini of the respective currents. Earth is
carried with greater velocity, the nearer it approaches to the
centre; fire is carried with greater velocity, the nearer it
approaches to the periphery. This shows that its current does not
stretch to infinity; for its velocity would then increase infinitely.
Earth is not carried downward by the force of any thing else, nor
fire upwards: not by any violence, nor by squeezing out ([Greek:
e)kthli/psei]), as some say. If this were so, a larger quantity of
earth would move downward, and a larger quantity of fire upward, more
slowly than a smaller. But the reverse is what occurs: the larger
quantity of earth moves downward more rapidly than the smaller; if
its motion had been caused by violence or by squeezing out, such
motion would have slackened as it became more widely distant from the
moving force (ss. 11-14).
We may deduce the same conclusion from the reasonings of the First
Philosophy, also from the fact of circular motion which of necessity
is constant both here and everywhere. Further, it is clear that there
can be only one Kosmos; for, as there are three bodily elements, so
there are three special places of such elements: one the undermost,
at the centre; another the uppermost, at the periphery, revolving in
a circular orbit; the third, in the intermediate place between the
two, being the light or floating element ([Greek: to\ e)pipo/lazon]);
for, if not there, it must be outside of the Kosmos, which is
impossible (ss. 15, 16).
CH. 9.--We must however now examine some reasons, which have been
alleged to prove the contrary; and which seem to show, not only that
there are many Kosmi, but even that there _must_ be many, and that
the hypothesis of one single Kosmos is inadmissible. It is urged that
in all aggregates, natural as well as artificial, the Form by itself
is one thing, and the Form implicated with Matter is another. When we
declare the definition of a sphere or a circle, we do not include
therein gold or brass, for this makes no part of the essence: if we
mention these metals, it is when we cannot conceive or grasp anything
beyond the particular case; for example, if we have one particular
circle before us. Nevertheless, even here the circle in the abstract
is one thing, and this particular circle is another: the first is the
Form by itself, the last is the Form along with Matter, one among
particular objects. Now, since the Heaven is perceivable by sense, it
must be one among particular objects; for every thing perceivable is
implicated with Matter. As such, it is _this_ Heaven: to be _this_
Heaven (Form along with Matter) is one thing; to be the Heaven simply
and absolutely (Form without Matter) is another. Now, wherever there
is Form, there either are or may be many distinct particulars;
whether we admit (with Plato) that the Forms exist separately, or
not. In all things where the Essence is implicated with Matter, we
see that the particular manifestations are many and of indefinite
number. Upon this reasoning therefore, there are or at least may be
many Heavens: the supposition that there can be no more than one, is
inadmissible (ss. 1-2).
But we must see how far this reasoning will hold. That the Form
without Matter differs from the Form with Matter, is perfectly true.
But this does not show that there must be many Kosmi; nor can there
be many, if this one Kosmos exhausts all the matter that exists. If
the matter of man were flesh and bone, and if a single man were
formed, including all flesh and all bone indissolubly united; there
could not possibly exist any other man; and the like is true about
other objects; for, where the essence is implicated with an
underlying matter, no object can come into existence unless some
matter be furnished. The Kosmos, or Heaven, is a particular object,
composed partly out of appropriate matter: but if it absorbs all the
appropriate matter, no second Kosmos can come to pass. We shall now
show that it does include all the appropriate matter (ss. 3-5).
The word Heaven has three different senses. 1. It means the essence
of the extreme periphery of the universe, or the natural body which
is there situated: we call this highest and farthest place Heaven,
where we suppose all the divine agency to be situated ([Greek: e)n
ô(=| to\ thei=on pa=n i(dru=sthai/ phamen]). 2. It means the body
continuous ([Greek: to\ suneche\s sô=ma]) with the extreme periphery
of the universe, wherein are contained Sun, Moon, and some of the
Stars (Planets); for these we affirm to be in the Heaven. 3. In a
third sense, it means the body circumscribed ([Greek:
periecho/menon]) by this extreme periphery: for we usually call the
Whole and the Universe, Heaven.--These being the three senses of
Heaven, the Whole circumscribed by the extreme periphery must by
necessity consist of all the natural and perceivable body existing,
since there neither is nor can be any such outside of the Heaven.
For, if there were any such outside of the Heaven, it must be either
one of the elements or a compound thereof--either by nature or
contrary to nature. For we have shown that each of the three
elements--the circular, the centrifugal, and the centripetal--has its
own special place by nature; and that, even if the place in which it
now is were not its natural place, that place would be the natural
place of another one among the three; for, if a place be contrary to
nature in reference to one, it must be conformable to nature in
reference to another. Neither of these three elements therefore can
be outside of the Heaven, nor, of course, any of their compounds. And
there exists no other body besides these; nor can **there exist
any other (ss. 6, 7).
We see therefore plainly that there neither is nor can be any mass of
body ([Greek: sô=matos o)/gkon]) outside of the Heaven; and that the
Heaven comprehends all matter--all body natural and perceptible. So
that there neither are, nor ever have been, nor ever can be, many
Heavens: this one is unique as well as perfect. Nor is there either
place, or vacuum, or time, outside of the Heaven. There is no place
or vacuum; because, if there were, body might be placed therein;
which we have shown to be impossible. There is no time; because time
is the number of motion, and there can be no motion without some
natural body; but there cannot exist any extra-celestial body.
Neither, therefore, are the things outside of the Heaven in place,
nor is there time to affect them with old age, nor do they undergo
change of any kind. They are without any change of quality and
without susceptibility of suffering; they remain, throughout the
entire Æon, in possession of the best and most self-sufficing life.
The word Æon is a divine expression proposed ([Greek: thei/ôs
e)/phthegktai]) by the ancient philosophers: they call the Æon of
each creature that end which circumscribes the natural duration of
the creature's life. Pursuant to this same explanation, the end of
the whole Heaven--the end comprising all time and the infinity of all
things--is Æon, so denominated [Greek: a)po\ tou= **a)ei\
ei)=nai], immortal and divine. From this is suspended existence and
life for all other things; for some closely and strictly, for others
faintly and feebly. For it is a doctrine often repeated to us in
ordinary philosophical discourse ([Greek: e)n toi=s e)gkukli/ois
philosophê/masi]) respecting divine matters--that the Divine, every
thing primary and supreme, is by necessity unchangeable; and this
confirms what has been just affirmed. For there exists nothing more
powerful than itself which can cause it to be moved (if there were,
_that_ would be more divine); nor has it any mean attribute; nor is
it deficient in any of the perfections belonging to its nature. Its
unceasing motion too is easily explained. For all things cease to be
moved, when they come into their own place; but with the circular or
revolving body the place in which it begins and in which it ends is
the same (ss. 8-10).
CH. 10.--We shall next discuss whether the Kosmos be generable or
ungenerable, and perishable or imperishable; noticing what others
have said on the subject before. All of them consider the Kosmos to
be generated: but some think it (although generated) to be eternal;
others look upon it as perishable, like other natural compounds;
others again--Empedokles and Herakleitus--declare it to be generated