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.

Great people plant trees they'll never sit under.

The fact of the religious vision, and its history of persistent expansion, is our one ground for optimism. Apart from it, human life is a flash of occasional enjoyments lighting up a mass of pain and misery, a bagatelle of transient experience.

A man of science doesn't discover in order to know, he wants to know in order to discover.

There are no whole truths: All truths are half-truths.

The task of a university is the creation of the future, so far as rational thought and civilized modes of appreciation can affect the issue.

The way in which the persecution of Galileo has been remembered is a tribute to the quiet commencement of the most intimate change in outlook which the human race had yet encountered. Since a babe was born in a manger, it may be doubted whether so great a thing has happened with so little stir