I wished by treating Psychology like a natural science, to help her become one.

Few people have definitely articulated philosophies of their own. But almost everyone has his own peculiar sense of a certain total character in the universe, and of the inadequacy of fully to match it [to] the peculiar systems that he knows.

The minute a man ceases to grow, no matter what his years, that minute he begins to be old.

The ideas gained by men before they are twenty-five are practically the only ideas they shall have in their lives.

To be fertile in hypotheses is the first perquisite of creativity and to be willing to throw them away the moment experience contradicts them is the next.

A sense of humor is just common sense dancing.

I am tired of the position of the dried-up critic and doubter. The believer is the true full man. (from a biography of James by Robert D. Richardson)