Religion is the last refuge of human savagery.

To be an abstraction does not mean that an entity is nothing. It merely means that its existence is only a factor of a more concrete element of nature.

After you understand about the sun and the stars and the rotation of the earth, you may still miss the radiance of the sunset.

No science can be more secure than the unconscious metaphysics which tacitly it presupposes.

Learning preserves the errors of the past, as well as its wisdom. For this reason, dictionaries are public dangers, although they are necessities.

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.

Knowledge shrinks as wisdom grows.