The principal effect of the passions is that they incite and persuade the mind to will the events for which they prepared the body.

If I go for the alternative which is false, then obviously I shall be in error; if I take the other side, then it is by... chance that I arrive at the truth, and I shall still be at fault.... In this incorrect use of free will may be found the privation which constitutes the essence of error.

There is a little gland in the brain in which the soul exercises its functions in a more particular way than in the other parts.

To live without philosophizing is in truth the same as keeping the eyes closed without attempting to open them.

Conquer yourself rather than the world.

And I shall always hold myself more obliged to those by whose favour I enjoy uninterrupted leisure than to any who might offer me the most honourable positions in the world.

The mind effortlessly and automatically takes in new ideas, which remain in limbo until verified or rejected by conscious, rational analysis.