Honesty is for the most part less profitable than dishonesty.
I have hardly ever known a mathematician who was capable of reasoning.
We ought to esteem it of the greatest importance that the fictions which children first hear should be adapted in the most perfect manner to the promotion of virtue.
There must always remain something that is antagonistic to good.
Entire ignorance is not so terrible or extreme an evil, and is far from being the greatest of all; too much cleverness and too much learning, accompanied with ill bringing-up, are far more fatal.
No evil can happen to a good man, either in life or after death.
Human behavior flows from three main sources: desire, emotion, and knowledge.
Philosophy is the highest music.
It is clear to everyone that astronomy at all events compels the soul to look upwards, and draws it from the things of this world to the other.
There are three classes of men; lovers of wisdom, lovers of honor, and lovers of gain.