Some of the finest moral intuitions come to quite humble people. The visiting of lofty ideas doesn't depend on formal schooling.

To come very near to a true theory, and to grasp its precise application, are two different things, as the history of science teaches us. Everything of importance has been said before by someone who did not discover it.

No Roman ever died in contemplation over a geometrical diagram.

In formal logic, a contradiction is the signal of defeat, but in the evolution of real knowledge it marks the first step in progress toward a victory.

Systems, scientific or philosophic, come and go. Each method of limited understanding is at length exhausted. In its prime each system is a triumphant success: in its decay it is an obstructive nuisance.

In England if something goes wrong--say, if one finds a skunk in the garden--he writes to the family solicitor, who proceeds to take the proper measures; whereas in America, you telephone the fire department. Each satisfies a characteristic need; in the English, love of order and legalistic procedure; and here in America, what you like is something vivid, and red, and swift.

To see what is general in what is particular, and what is permanent in what is transitory, is the aim of scientific thought.