On The Heavens   

it exists in actuality-but of not existing last year or in the past.

Now suppose it to be in actuality what it is capable of being. It will

then be true to say now that it does not exist last year. But this

is impossible. No capacity relates to being in the past, but always to

being in the present or future. It is the same with the notion of an

eternity of existence followed later by non-existence. In the later

state the capacity will be present for that which is not there in

actuality. Actualize, then, the capacity. It will be true to say now

that this exists last year or in the past generally.

Considerations also not general like these but proper to the subject

show it to be impossible that what was formerly eternal should later

be destroyed or that what formerly was not should later be eternal.

Whatever is destructible or generated is always alterable. Now

alteration is due to contraries, and the things which compose the

natural body are the very same that destroy it.



Book II

1



THAT the heaven as a whole neither came into being nor admits of

destruction, as some assert, but is one and eternal, with no end or

beginning of its total duration, containing and embracing in itself

the infinity of time, we may convince ourselves not only by the

arguments already set forth but also by a consideration of the views

of those who differ from us in providing for its generation. If our

view is a possible one, and the manner of generation which they assert

is impossible, this fact will have great weight in convincing us of

the immortality and eternity of the world. Hence it is well to

persuade oneself of the truth of the ancient and truly traditional

theories, that there is some immortal and divine thing which possesses

movement, but movement such as has no limit and is rather itself the

limit of all other movement. A limit is a thing which contains; and