He alone is free who lives with free consent under the entire guidance of reason.

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

I would warn you that I do not attribute to nature either beauty or deformity, order or confusion. Only in relation to our imagination can things be called beautiful or ugly, well-ordered or confused.

There is no hope unmingled with fear, and no fear unmingled with hope.

Fear cannot be without hope nor hope without fear.

Freedom is absolutely necessary for the progress in science and the liberal arts.

All happiness or unhappiness solely depends upon the quality of the object to which we are attached by love.

Happiness is a virtue, not its reward.

Fear cannot be without hope nor hope without fear.

There is no hope unmingled with fear, and no fear unmingled with hope.