No man of science wants merely to know. He acquires knowledge to appease his passion for discovery. He does not discover in order to know, he knows in order to discover.

...the self-satisfied dogmatism with which mankind at each period of its history cherishes the delusion of the finality of existing modes of knowledge.

Learning preserves the errors of the past as well as its wisdom.

Our reasonings grasp at straws for premises and float on gossamers for deductions.

It does not matter what men say in words, so long as their activities are controlled by settled instincts. The words may ultimately destroy the instincts; but until this has occurred, words do not count.

The art of progress is to preserve order amid change and to preserve change amid order.

Education should turn out the pupil with something he knows well and something he can do well.