Every one who has seriously investigated a novel question, who has really interrogated Nature with a view to a distinct answer, will bear me out in saying that it requires intense and sustained effort of imagination.

The true function of philosophy is to educate us in the principles of reasoning and not to put an end to further reasoning by the introduction of fixed conclusions.

When a man fails to see the truth of certain generally accepted views, there is no law compelling him to provoke animosity by announcing his dissent.

All good Literature rests primarily on insight.

It is not enough that a man has clearness of vision, and reliance on sincerity, he must also have the art of expression, or he will remain obscure.

Mathematicians do not write for the circulating library.

Personal experience is the basis of all real literature.