I feel a complete thirst for knowledge and an eager unrest to go further in it as well as satisfaction at every acquisition. There was a time when I believed that this alone could constitute the honor of mankind, and I had contempt for the ignorant rabble who know nothing.

There is no virtue in penance and fasting which waste the body; they are only fanatical and monkish.

From such crooked wood as that which man is made of, nothing straight can be fashioned.

Physicians think they are doing something for you by labeling what you have as a disease

Have the courage to use your own reason- That is the motto of enlightenment. "Foundations of the Metaphysics of Morals" (1785)

Genius is the ability to independently arrive at and understand concepts that would normally have to be taught by another person.

Act in such a way that you treat humanity, whether in your own person or in the person of any other, never merely as a means to an end, but always at the same time as an end.