Peirce, Charles Sanders

"Matter is a secondary phenomenon."

"The freedom which we commonly call freedom of the will is impossible unless necessity be denied."

"Signs are the vehicles by which the mind grasps the world."

"Every word is a symbol whose meaning grows with experience."

"The achievement of objective truth demands the cooperation of minds."

"We are thinking animals, not thinking machines."

"The essence of pragmatism is to grasp hold of the practical consequences."

"Time is a sign, and all signs take time to develop their full meaning."

"The ultimate result of thought is action, and the ultimate satisfaction is happiness."

"The mind of man is a symbol."

"Reasoning is of three kinds: deduction, induction, and abduction."

"A man should render himself such company as he wishes to keep."

"The beauty of a theory is that it has no need of the crutch of facts."

"Man is not bound to render an account of his dreams."

"Continuity is the idea of the infinitesimal."

"The idea that a sign can exist without an object is quite opposed to the definition of a sign."

"We are all born with intuitions that we cannot possibly explain."

"A person is not absolutely an individual."

"There is one thing even the United States has not learned, how to take care of its industrial army."

"The elements of every concept enter into every proposition."

"Language is not something that can be separated from the human world."

"It is a common observation that anything concerning mathematics becomes uninteresting to many people."

"The theory of chances is the only mathematics for practical men."

"Nothing is so desperately monotonous as the sea, and I no longer wonder at the cruelty of pirates."

"Every man has a philosophy, and he cannot avoid having one."

"The development of reason must be strictly experimental in character."

"The practical spirit of science is its only valuable spirit."

"What is the cause of a thing's being in existence?"

"Man makes the world, and the world makes man."

"A false idea is one that would not work."