I believe my theory of relativity to be true. But it will only be proved for certain in 1981, when I am dead.

Nature hides her secrets because of her essential loftiness, but not by means of ruse.

A conflict arises when a religious community insists on the absolute truthfulness of all statements recorded in the Bible. This means an intervention on the part of religion into the sphere of science; this is where the struggle of the Church against doctrines of Galileo and Darwin belongs.

They come into being not through demonstration but through revelation, through the medium of powerful personalities.

[Freud's] sense of reality is less clouded by wishful thinking than is the case with other people and [he combines] the qualities of critical judgment, earnestness and responsibility.

There is, however, one other human right which is infrequently mentioned but which seems to be destined to become very important: this is the right, or the duty, of the individual to abstain from cooperating in activities which he considers wrong or pernicious.

I believe that Gandhi’s views were the most enlightened of all the political men of our time.