Ἀριστοτέλης

Aristotle is the last Greek philosopher who faces the world cheerfully; after him, all have, in one form or another, a philosophy of retreat. The world is bad; let us learn to be independent of it. External goods are precarious; they are the gift of fortune, not the reward of our own efforts.

Bertrand Russell

Not only is he the last Greek philosopher with such an attitude. He was the last philosopher who faces the world cheerfully (perhaps before Ayn Rand).