《论天（英文）》经典中外文学教育丛书.pdf

ON THE HEAVENS

by Aristotle

translated by J. L. Stocks

Book I

1

THE science which has to do with nature clearly concerns itself for the
most part with bodies and magnitudes and their properties and movements,
but also with the principles of this sort of substance, as many as they may be.
For of things constituted by nature some are bodies and magnitudes, some
possess body and magnitude, and some are principles of things which
possess these. Now a continuum is that which is divisible into parts always
capable of subdivision, and a body is that which is every way divisible. A
magnitude if divisible one way is a line, if two ways a surface, and if three a
body. Beyond these there is no other magnitude, because the three
dimensions are all that there are, and that which is divisible in three directions
is divisible in all. For, as the Pythagoreans say, the world and all that is in it is
determined by the number three, since beginning and middle and end give
the number of an ’all’, and the number they give is the triad. And so, having
taken these three from nature as (so to speak) laws of it, we make further use
of the number three in the worship of the Gods. Further, we use the terms in
practice in this way. Of two things, or men, we say ’both’, but not ’all’: three is
the first number to which the term ’all’ has been appropriated. And in this, as
we have said, we do but follow the lead which nature gives. Therefore, since
’every’ and ’all’ and ’complete’ do not differ from one another in respect of
form, but only, if at all, in their matter and in that to which they are applied,
body alone among magnitudes can plete. For it alone is determined
by the three dimensions, that is, is an ’all’. But if it is divisible in three
dimensions it is every way divisible, while the other magnitudes are divisible
in one dimension or in two alone: for the divisibility and continuity of
magnitudes depend upon