On Generation and corruption   

exhibit them, why they do so, and in what manner. We must go on to

discuss how it is possible for action and passion to take place.



8



Some philosophers think that the 'last' agent-the 'agent' in the

strictest sense-enters in through certain pores, and so the patient

suffers action. It is in this way, they assert, that we see and hear

and exercise all our other senses. Moreover, according to them, things

are seen through air and water and other transparent bodies, because

such bodies possess pores, invisible indeed owing to their minuteness,

but close-set and arranged in rows: and the more transparent the body,

the more frequent and serial they suppose its pores to be. Such was

the theory which some philosophers (induding Empedocles) advanced in

regard to the structure of certain bodies. They do not restrict it

to the bodies which act and suffer action: but 'combination' too, they

say, takes place 'only between bodies whose pores are in reciprocal

symmetry'. The most systematic and consistent theory, however, and one

that applied to all bodies, was advanced by Leucippus and

Democritus: and, in maintaining it, they took as their

starting-point what naturally comes first.

For some of the older philosophers thought that 'what is' must of

necessity be 'one' and immovable. The void, they argue, 'is not':

but unless there is a void with a separate being of its own, 'what is'

cannot be moved-nor again can it be 'many', since there is nothing

to keep things apart. And in this respect, they insist, the view

that the universe is not 'continuous' but 'discretes-in-contact' is no

better than the view that there are 'many' (and not 'one') and a void.

For (suppose that the universe is discretes-in-contact. Then), if it

is divisible through and through, there is no 'one', and therefore

no 'many' either, but the Whole is void; while to maintain that it

is divisible at some points, but not at others, looks like an