"Laughter is an affect resulting from the sudden transformation of a heightened expectation into nothing."

"Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck."

"In all judgements by which we describe anything as beautiful, we allow no one to be of another opinion."

"Out of the crooked timber of humanity, no straight thing was ever made."

"As nature has uncovered from under this hard shell the seed for which she most tenderly cares - the propensity and vocation to free thinking - this gradually works back upon the character of the people, who thereby gradually become capable of managing freedom; finally, it affects the principles of government, which finds it to its advantage to treat men, who are now more than machines, in accordance with their dignity."

"A categorical imperative would be one which represented an action as objectively necessary in itself, without reference to any other purpose."

"Live your life as though your every act were to become a universal law."

"The only objects of practical reason are therefore those of good and evil. For by the former is meant an object necessarily desired according to a principle of reason; by the latter one necessarily shunned, also according to a principle of reason."

"An action, to have moral worth, must be done from duty."

"We must admit thatlaw must be valid, not merely for men, but for all rational creatures generally, not merely under certain contingent conditions or with exceptions, but with absolute necessity."

"Ingratitude is the essence of vileness."

"The main point of enlightenment is man's release from his self-caused immaturity, primarily in matters of religion."

"If I have a book that thinks for me, a pastor who acts as my conscience, a physician who prescribes my diet, and so on... then I have no need to exert myself. I have no need to think, if only I can pay; others will take care of that disagreeable business for me."

"All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason."

"The desire of a man for a woman is not directed at her because she is a human being but because she is a woman. That she is a human being is of no concern to him."

"Immaturity is the incapacity to use one's intelligence without the guidance of another."

"The true religion is to be posited not in the knowledge or confession of what God allegedly does or has done for our salvation, but in what we must do to become worthy of this."