The philosopher is in love with truth, that is, not with the changing world of sensation, which is the object of opinion, but with the unchanging reality which is the object of knowledge.

All things will be produced in superior quantity and quality, and with greater ease, when each man works at a single occupation, in accordance with his natural gifts, and at the right moment, without meddling with anything else.

Man...is a tame or civilized animal; never the less, he requires proper instruction and a fortunate nature, and then of all animals he becomes the most divine and most civilized; but if he be insufficiently or ill- educated he is the most savage of earthly creatures.

To win over your bad self is the grandest and foremost of victories.

The true lover of knowledge naturally strives for truth, and is not content with common opinion, but soars with undimmed and unwearied passion till he grasps the essential nature of things.

True friendship can exist only between equals.

Atheism is a disease of the soul before it becomes an error of understanding.