Aristotle
produced here by the sound of the celestial bodies must be violent
beyond all endurance. But there is good reason why we neither hear
nor suffer any thing from them; viz., that they make no sound. The
cause thereof is one which attests the truth of my doctrine laid down
above--That the stars are not moved of themselves, but carried round
by and in the circle to which they are fastened. Bodies thus carried
round, make no sound or shock: it is only bodies carried round of
themselves that make sound and shock. Bodies which are fastened in,
or form parts of, a revolving body, cannot possibly sound, any more
than the parts of a ship moving, nor indeed could the whole ship
sound, if carried along in a running river. Yet the Pythagoreans
might urge just the same reasons to prove that bodies so large as the
mast, the stern, and the entire ship, could not be moved without
noise. Whatever is carried round, indeed, in a medium not itself
carried round, really makes sound; but it cannot do so, if the medium
itself be carried round continuously. We must therefore in this case
maintain that, if the vast bodies of the stars were carried round in
a medium either of air or of fire (whose motion is rectilinear), as
all men say that they are, they must necessarily make a prodigious
sound, which would reach here to us and would wear us out ([Greek:
diaknai/ein]). Since nothing of this nature occurs, we may be sure
that the stars are not carried round in a current of their own,
either animated or violent. It is as if Nature had foreseen the
consequence, that, unless the celestial motions were carried on in
the manner in which they are carried on, nothing of what now takes
place near us ([Greek: tô=n peri\ to\n deu=ro to/pon]), could have
been as it is now. I have thus shown that the stars are spherical,
and that they are not moved by a motion of their own (ss. 2-5).
CH. 10.--Respecting the arrangement of the stars--how each of them is
placed, some anterior others posterior, and what are their distances
from each other--the books on astronomy must be consulted and will
explain. It consists with the principles there laid down, that the
motions of the stars (planets) should be proportional to their
distances, some quicker, others slower. For, since the farthest
circle of the Heaven has a revolution both simple and of extreme
velocity, while the revolutions of the other stars (planets) are many
in number and slower, each of them being carried round in its own
circle in the direction contrary to that of the first or farthest
circle of the Heaven, the reasonable consequence is, that that planet
which is nearest to the first and simple revolving circle takes the
longest time to complete its own (counter-revolving) circle, while
that which is most distant from the same circle takes the shortest
time, and the remaining planets take more or less time in proportion
as they are nearer or farther. For the planet nearest to the first
revolving circle has its own counterrevolution most completely
conquered or overpowered thereby; the planet farthest from the same,
has its own counterrevolution least conquered thereby; and the
intermediate planets more or less in inverse proportion to their
distances from the same, as mathematicians demonstrate.
CH. 11.--We may most reasonably assume the figure of the stars to be
spherical. For, since we have shown that it is not their nature to
have any motion of their own, and since Nature does nothing either
irrational or in vain, it is plain that she has assigned to the
immovables that figure which is least fit for motion; which figure is
the sphere, as having no organ for motion. Besides, what is true of
one is true of all ([Greek: e)/ti d' o(moi/ôs me\n a(/panta kai\
e(/n]): now the Moon may be shown to be spherical, first, by the
visible manifestations which she affords in her waxings and wanings,
next, from astronomical observations of the eclipses of the Sun.
Since therefore one among the stars is shown to be spherical, we may
presume that the rest will be so likewise.
CH. 12.--I proceed to two other difficulties, which are well
calculated to perplex every one. We must try to state what looks most
like truth, considering such forwardness not to be of the nature of
audacity, but rather to deserve respect, when any one, stimulated by
the thirst for philosophy, contents himself with small helps and
faint approximations to truth, having to deal with the gravest
difficulties.
1. Why is it, that the circles farthest from the outermost circle (or
Aplanês) are not always moved by a greater number of motions than
those nearer to it? Why are some of the intermediate circles (neither
farthest nor nearest) moved by a greater number of motions than any
of the others? For it would seem reasonable, when the First Body is
moved by one single rotatory current, that the one nearest to it
should be moved by two, the next nearest by three, and so on in
regular sequence to those which are more distant. But we find that
the reverse occurs in fact: Sun and Moon have fewer movements than
some of the planets, which are nevertheless farther from the centre,
and nearer to the First Body. In regard to some of the planets, we
know this by visual evidence; for we have seen the Moon when at
half-moon passing under Mars, who was occulted by the dark part of her
body, and emerged on the bright side of it. The like is attested
respecting the other planets, by the Egyptians and Babylonians, the
most ancient of all observers.
2. Why is it, that in the First Revolution (in the revolution of the
First Heaven or First Body) there is included so vast a multitude of
stars as to seem innumerable; while in each of the others there is
one alone and apart, never two or more fastened in the same current?
Here are two grave difficulties, which it is well to investigate and
try to understand, though our means of information are very scanty,
and though we stand at so great a distance from the facts. Still, as
far as we can make out from such data, these difficulties would not
seem to involve any philosophical impossibility or incongruity. Now
we are in the habit of considering these celestial bodies as bodies
only; and as monads which have indeed regular arrangement, but are
totally destitute of soul or vital principle. (When Aristotle here
says _we_, he must mean the philosophers whose point of view he is
discussing: for the general public certainly did not regard the Sun,
Moon, and stars as [Greek: a)/psucha pa/mpan], but, on the contrary,
considered this as blameable heresy, and looked upon them as
Gods**.) We ought, however, to conceive them as partaking of life
and action ([Greek: dei= d' ô(s metecho/ntôn u(polamba/nein
pra/xeôs kai\ zôê=s]); and in this point of view the actual state
of the case will appear nowise unreasonable (s. 2). For we should
naturally expect that to that which is in the best possible
condition, such well-being will belong without any agency at all; to
that which is next best, through agency single and slight; to such as
are farther removed in excellence of condition, through action more
multiplied and diversified. Just so in regard to the human body: the
best constituted body maintains its good condition without any
training at all; there are others which will do the same at the cost
of nothing more than a little walking; there are inferior bodies
which require, for the same result, wrestling, running, and other
motions; while there are even others which cannot by any amount of
labour attain a good condition, but are obliged to be satisfied with
something short of it (s. 3). Moreover it is difficult to succeed in
many things, or to succeed often: you may throw one or two sixes with
the dice, but you cannot throw ten thousand; and, farther, when the
conditions of the problem become complicated--when one thing is to be
done for the sake of another, that other for a third result, and that
third for a fourth, &c.--success, which may be tolerably easy when
the steps are only few, the more they are multiplied, becomes harder
and harder.
Hence we must consider the agency of the stars as analogous to that
of plants and animals. For here the agency of man is most
multifarious, since he is capable of attaining many varieties of
good, and accordingly busies himself about many things and about one
thing for the sake of others. The agency of other animals on the
other hand is more restricted; that of plants yet more so, being of
slight force and only of one special character (s. 4). But that which
exists in the best possible condition stands in no need of acting or
agency; for it already possesses that for the sake of which action is
undertaken. Now action always includes two elements--that for the
sake of which and what is for the sake thereof--the end and the
means: there is either some one end, which the agent may attain, as
in the case of man; or there are many different matters all of which
may be used as means towards the best possible condition. Thus one
agent possesses and partakes of the best possible condition; another
comes near to it with little trouble; a third, with much trouble; a
fourth does not even aspire to the end, but is competent only to
arrive near to the last of the means. For example, let health be the
end: one man is always in health; a second becomes so, by being
starved down; a third by that, combined with running exercise; a
fourth is obliged to take some additional exercise, in order to
qualify himself for running, so that his motions are multiplied; a
fifth is incapable of arriving at health, but arrives only at the
running and the being thinned down, one of which in this case serves
as end. For it would be best for all, if they could attain the
supreme end--health; but, if that be impossible, then the next best
thing is to get as near to the best as possible (ss. 5-7).
For this reason the Earth is not moved at all, and the matters near
the Earth are moved with few motions; since they do not arrive at the
extreme best, but only as near as their ability permits to obtain or
hit the supremely divine principle; while the First Heaven, on the
contrary, obtains or hits it at once, through one single motion; and
the bodies intermediate between the First Heaven and those which are
last (or nearest to the Earth), obtain it or arrive at it also, but
only through a greater number of motions.
There is the other difficulty also to be considered--that vast
multitude of stars are put all together in the one single First
Current or Revolution, but each of the other stars (planets) has its
own motions singly and apart. The principal reason of this we may
fairly suppose to be that it follows as a natural consequence from
the vast superiority of the first, in each variety of life and in
each beginning, over all posterior to the first. Here the First
Current or Revolution, being one and by itself, moves many of the
divine bodies, while the others (secondary or countercurrents),
numerous as they are, move each only one; for each one of these
wandering bodies or planets is carried by many different currents.
Thus Nature establishes equalization and a sort of symmetry, by
assigning, in the one case, many bodies to one current, and in the
other, many currents to one body (ss. 8-10). Beside this principal
reason, there is also another. The other currents have each one body
only, because motion is given to many bodies by all of them prior to
the last which bears the one star. For the last sphere is carried
round fastened into many spheres, and each sphere is a body (ss. 11,
12. I do not clearly understand the lines that follow:--[Greek:
e)kei/nês a)\n ou)=n koino\n ei)/ê to\ e)/rgon; au(/tê me\n ga\r
e(ka/stê| ê( i)/dios phu/sei phora/; au(/tê de\ oi(=on