Home | Texts by category | | Quick Search:   
Works by Aristotle
Pages of On The Heavens

Previous | Next

On The Heavens   

Similar difficulties are involved in all other methods of

distinction, whether they account for the relative lightness and

heaviness of bodies by distinctions of size, or proceed on any other

principle, so long as they attribute to each the same matter, or

even if they recognize more than one matter, so long as that means

only a pair of contraries. If there is a single matter, as with

those who compose things of triangles, nothing can be absolutely heavy

or light: and if there is one matter and its contrary-the void, for

instance, and the plenum-no reason can be given for the relative

lightness and heaviness of the bodies intermediate between the

absolutely light and heavy when compared either with one another or

with these themselves. The view which bases the distinction upon

differences of size is more like a mere fiction than those

previously mentioned, but, in that it is able to make distinctions

between the four elements, it is in a stronger position for meeting

the foregoing difficulties. Since, however, it imagines that these

bodies which differ in size are all made of one substance, it implies,

equally with the view that there is but one matter, that there is

nothing absolutely light and nothing which moves upward (except as

being passed by other things or forced up by them); and since a

multitude of small atoms are heavier than a few large ones, it will

follow that much air or fire is heavier than a little water or

earth, which is impossible.


These, then, are the views which have been advanced by others and

the terms in which they state them. We may begin our own statement

by settling a question which to some has been the main

difficulty-the question why some bodies move always and naturally

upward and others downward, while others again move both upward and

downward. After that we will inquire into light and heavy and of the

Previous | Next
Site Search