Peirce, Charles Sanders

"Whatever grows is in part the product of chance."

"Life is growth; hence life means a constant change."

"The knowledge we have acquired ought not to be jealously hoarded but freely shared."

"I came across a passage which told of a person being 'melancholy' from having read too much; this struck me as very absurd."

"I am too much of a scholastic ever to be satisfied with anyone's knowledge, much less with my own."

"Truth is public. It is what would be ultimately agreed upon by an indefinite community of inquirers."

"The elements of every concept enter into logical thought at a level quite below consciousness."

"No discovery of mine has made ten men wiser."

"Every symbol is determined by its object, either directly or indirectly."

"There are three grades of clearness in our apprehension of a proposition."

"The universe is a vast symbolic medium."

"All experience is of the nature of meaning."

"The consciousness of an error is the first step toward correcting it."

"Philosophy ought to imitate the successful sciences in its methods."

"The riddle of the universe is the object of philosophy and of every serious mind."

"Most of the leading intellectuals of the world have declared themselves unable to believe in the immortality of the soul."

"A person is nothing else than a sign."

"I do not believe in the popular religions at all."

"Whatever is to be found in a well-developed mind is to be found in the world."

"The true meaning of a sign is the effect which it has on the understanding of those who perceive it."

"The habit-taking of the mind explains the most elevated aspects of human activity."

"There is a good deal of confusion about the definition of truth."

"The object of reasoning is to find out, from the consideration of what we already know, something else which we do not know."

"Doubt is the key to all knowledge."

"The method of authority may have worked well enough for the indefinite future, but the history of science shows that it does not satisfy."

"A thing has the properties which experience has shown it to have."

"The intellectual semination of ideas is as real as the physical semination of seeds."

"To be real is to have a dynamic effect."

"The highest grade of reality is exemplified by whatever is altogether determinate."

"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself."