“a life without investigation is not worth living”

“But the truth is, O men of Athens, that God only is wise; and by his answer he intends to show that the wisdom of men is worth little or nothing; he is not speaking of Socrates, he is only using my name by way of illustration, as if he said, He, O men, is the wisest, who, like Socrates, knows that his wisdom is in truth worth nothing.”

“Rather I think that a man who ... is willing ... to value learning as long as he lives, not supposing that old age brings him wisdom of itself, will necessarily pay more attention to the rest of his life.”

“True opinions are a fine thing and do all sorts of good so long as they stay in their place; but they will not stay long. They run away from a man's mind, so they are not worth much until you tether them by working out the reason. Once they are tied down, they become knowledge, and are stable.”

“The greatest wealth is to live content with little.”

“Do you desire to be wholly one; always day and night in one another's company? For if this is what you desire, I am ready to melt and fuse you together, so that being two you shall become one, and while you live a common life as if you were a single man, and after your death in the world below still be one departed soul, instead of two....”

“He who approaches the temple of the Muses without inspiration, in the belief that craftsmanship alone suffices, will remain a bungler and his presumptuous poetry will be obscured by the songs of the maniacs.”