Socrates ( Wikipedia bio )
"The unexamined life is not worth living" ― Plato's Apology (38a5–6)
“The heaviest penalty for declining to rule is to be ruled by someone inferior to yourself.” ― Plato, The Republic
“Socrates: But why, my dear Crito, should we care about the opinion of the many?” ― Plato's Crito
“For as there are misanthropists, or haters of men, there are also misologists, or haters of ideas, and both spring from the same cause, which is ignorance of the world.” ― Plato's Phaedo
"Socrates: I prefer nothing, unless it is true.” ― Euthyphro by Plato
"Socrates: man cannot enquire either about that which he knows, or about that which he does not know; for if he knows, he has no need to enquire; and if not, he cannot; for he does not know the, very subject about which he is to enquire.” ― Plato's "Meno"
Pythagoras ( Wikipedia bio )
“Untaught boys confound letters, but uneducated men, things.” ― Golden Verses, Similitudes Of Demophilus #32