Full Idea
That which has reason is more perfect than that which has not. But there is nothing more perfect than the universe; therefore the universe is a rational being.
Gist of Idea
Things are more perfect if they have reason; nothing is more perfect than the universe, so it must have reason
Source
Zeno (Citium) (fragments/reports [c.294 BCE]), quoted by M. Tullius Cicero - On the Nature of the Gods ('De natura deorum') II.20
Book Reference
Cicero: 'The Nature of the Gods', ed/tr. McGregor,Horace [Penguin 1972], p.132