Believe nothing because it is written in books. Believe nothing because wise men say it is so. Believe nothing because it is religious doctrine. Believe it only because you yourself know it to be true.
The soul is no traveller; the wise man stays at home, and when his necessities, his duties, on any occasion call him from his house, or into foreign lands, he is at home still, and shall make men sensible by the expression of his countenance, that he goes the missionary of wisdom and virtue, and visits cities and men like a sovereign, and not like an interloper or a valet.
To be free is not necessarily to be wise. Wisdom comes with counsel, with the frank and free conference of untrammeled men united in the common interest.
Meat is not agreeable to the wise: it has a nauseating odor, it causes a bad reputation, it is food for the carnivorous; I say this, Mahamati, it is not to be eaten.
The argument of Alcidamas: Everyone honours the wise. Thus the Parians have honoured Archilochus, in spite of his bitter tongue; the Chians Homer, though he was not their countryman; the Mytilenaeans Sappho, though she was a woman; the Lacedaemonians actually made Chilon a member of their senate, though they are the least literary of men; the inhabitants of Lampsacus gave public burial to Anaxagoras, though he was an alien, and honour him even to this day.