"A human being who is supposed to make use of his reason for himself needs only freedom, nothing else."

"Experience is the product of the understanding applying its concepts to sensory data."

"The Negroes and Americans will hence never be capable of founding an orderly civil society for themselves."

"Experience without theory is blind, but theory without experience is mere intellectual play."

"Act only according to that maxim whereby you can at the same time will that it should become a universal law without contradiction."