When a person supposes that he knows, and does not know; this appears to be the great source of all the errors of the intellect.

That makes me think, my friend, as I have often done before, how natural it is that those who have spent a long time in the study of philosophy appear ridiculous when they enter the courts of law as speakers. Those who have knocked about in courts and the like from their youth up seem to me, when compared with those who have been brought up in philosophy and similar pursuits, to be as slaves in breeding compared with freemen.

Entire ignorance is not so terrible or extreme an evil, and is far from being the greatest of all.

They (the poets) are to us in a manner the fathers and authors of the wisdom.

But this is not difficult, O Athenians! to escape death; but it is much more difficult to avoid depravity, for it runs swifter than death. And now I, being slow and aged, am overtaken by the slower of the two; but my accusers, being strong and active, have been overtaken by the swifter, wickedness. And now I depart, condemned by you to death; but they condemned by truth, as guilty of iniquity and injustice: and I abide my sentence, and so do they. These things, perhaps, ought so to be, and I think that they are for the best.

Seek truth while you are young, for if you do not, it will later escape your grasp

All soul is immortal. For that which is always in movement is immortal; that which moves something else, and is moved by something else, in ceasing from movement ceases from living. So only that which moves itself, because it does not abandon itself, never stops moving. But it is also source and first principle of movement for the other things which move.