On The Heavens   

only that there is not, but also that there could never come to be,

any bodily mass whatever outside the circumference. The world as a

whole, therefore, includes all its appropriate matter, which is, as we

saw, natural perceptible body. So that neither are there now, nor have

there ever been, nor can there ever be formed more heavens than one,

but this heaven of ours is one and unique and complete.

It is therefore evident that there is also no place or void or

time outside the heaven. For in every place body can be present; and

void is said to be that in which the presence of body, though not

actual, is possible; and time is the number of movement. But in the

absence of natural body there is no movement, and outside the

heaven, as we have shown, body neither exists nor can come to exist.

It is clear then that there is neither place, nor void, nor time,

outside the heaven. Hence whatever is there, is of such a nature as

not to occupy any place, nor does time age it; nor is there any change

in any of the things which lie beyond the outermost motion; they

continue through their entire duration unalterable and unmodified,

living the best and most selfsufficient of lives. As a matter of fact,

this word 'duration' possessed a divine significance for the ancients,

for the fulfilment which includes the period of life of any

creature, outside of which no natural development can fall, has been

called its duration. On the same principle the fulfilment of the whole

heaven, the fulfilment which includes all time and infinity, is

'duration'-a name based upon the fact that it is always-duration

immortal and divine. From it derive the being and life which other

things, some more or less articulately but others feebly, enjoy. So,

too, in its discussions concerning the divine, popular philosophy

often propounds the view that whatever is divine, whatever is

primary and supreme, is necessarily unchangeable. This fact confirms

what we have said. For there is nothing else stronger than it to

move it-since that would mean more divine-and it has no defect and

lacks none of its proper excellences. Its unceasing movement, then, is