“Nothing is so firmly believed as that which is least known.”

“Can anything be imagined so ridiculous, that this miserable and wretched creature [man], who is not so much as master of himself, but subject to the injuries of all things, should call himself master and emperor of the world, of which he has not power to know the least part, much less to command the whole?”

“Nothing fixes a thing so intensely in the memory as the wish to forget it.”

“To compensate a little for the treachery and weakness of my memory, so extreme that it has happened to me more than once to pick up again...books which I have read carefully a few years before. I have adopted the habit for some time now of adding at the end of each book the time I finished reading it and the judgment I have derived of it as a whole, so that this may represent to me at least the sense and general idea I had conceived of the author in reading it.”

“Let this variety of ideas be set before him; he will choose if he can; if not, he will remain in doubt. Only the fools are certain and assured. For if he embraces Xenophon's and Plato's opinions by his own reasoning, they will no longer be theirs, they will be his. He who follows another follows nothing. He finds nothing; indeed he seeks nothing. We are not under a king; let each one claim his own freedom [Seneca]. Let him know that he knows, at least. He must imbibe their ways of thinking, not learn their precepts. And let him boldly forget, if he wants, where he got them, but let him know how to make them his own. Truth and reason are common to everyone, and no more belong to the man who first spoke them than to the man who says them later. It is no more according to Plato than according to me, since he and I understand and see it the same way. The bees plunder the flowers here and there, but afterward they make of them honey, which is all theirs; it is no longer thyme or marjoram. Even so with the pieces borrowed from others; he will transform and blend them to make a work of his own, to wit, his judgment. His education, work, and study aim only at forming this.”

“Let the tutor make his charge pass everything through a sieve and lodge nothing in his head on mere authority and trust: let not Aristotle's principles be principles to him any more than those of the Stoics or Epicureans. Let this variety of ideas be set before him; he will choose if he can; if not, he will remain in doubt. Only the fools are certain and assured. For if he embraces Xenophon's and Plato's opinions by his own reasoning, they will no longer be theirs, they will be his. He who follows another follows nothing. He finds nothing; indeed he seeks nothing. We are not under a king; let each one claim his own freedom. Let him know that he knows, at least. He must imbibe their ways of thinking, not learn their precepts. And let him boldly forget, if he wants, where he got them, but let him know how to make them his own. Truth and reason are common to everyone, and no more belong to the man who first spoke them than to the man who says them later. It is no more according to Plato than according to me, since he and I understand and see it the same way. The bees plunder the flowers here and there, but afterward they make of them honey, which is all theirs; it is no longer thyme or marjoram. Even so with the pieces borrowed from others; he will transform and blend them to make a work of his own, to wit, his judgment. His education, work, and study aim only at forming this.”

“When I am attacked by gloomy thoughts,nothing helps me so much as running to my books.They quickly absorb me and banish the clouds from my mind.”