Only that thing is free which exists by the necessities of its own nature, and is determined in its actions by itself alone.

The most tyrannical of governments are those which make crimes of opinions, for everyone has an inalienable right to his thoughts.

A man is as much affected pleasurably or painfully by the image of a thing past or future as by the image of a thing present.

Desire is the essence of a man.

In practical life we are compelled to follow what is most probable ; in speculative thought we are compelled to follow truth.

Will and intellect are one and the same thing.

If you want the present to be different from the past, study the past.