Be careful who you choose as your enemy because that's who you become most like.

What is the strongest cure?--Victory.

It is only great pain--that slow, sustained pain that takes its time, in which we are, as it were, burned with smoldering green firewood--that forces us philosophers to sink to our ultimate profundity and to do away with all the trust, everything good-natured, veil-imposing, mild and middling, on which we may have previously based our humanity. I doubt that such a pain makes us 'better'--but I know that it makes us deeper.

[Heraclitus] did not require humans or their sort of knowledge, since everything into which one may inquire he despises [as being] in contrast [to his own] inward-turning wisdom. [To him] all learning from others is a sign of nonwisdom, because the wise man focuses his vision on his own intelligence.

He who has attained the freedom of reason to any extent cannot, for a long time, regard himself otherwise than as a wanderer on the face of the earth - and not even as a traveler towards a final goal, for there is no such thing. But he certainly wants to observe and keep his eyes open to whatever actually happens in the world; therefore he cannot attach his heart too firmly to anything individual; he must have in himself something wandering that takes pleasure in change and transitoriness.

Just as bones, tissues, intestines, and blood vessels are enclosed in a skin that makes it possible to bear the sight of a human being, so the agitations and passions of the soul are wrapped up in vanity: it is the soul's skin.

It is the privilege of greatness to confer intense happiness with insignificant gifts.