I have learned more from my mistakes than from my successes.

The well-mannered man never puts out his hand in greeting until a lady extends hers. This is a test of good breeding that is constantly applied. ... The first move in the direction of cordiality must come from the lady, the whole code of behaviour being based on the assumption that she is the social superior.

The art galleries of Paris contain the finest collection of frames I ever saw.

We must reason in natural philosophy not from what we hope, or even expect, but from what we perceive.

Consistency in opinion is the slow poison of intellectual life, the destroyer of its vividness and energy.

Nothing is so dangerous to the progress of the human mind than to assume that our views of science are ultimate, that there are no mysteries in nature, that our triumphs are complete and that there are no new worlds to conquer.

This sentiment of self-contempt is a frequent one in young people of both sexes. Their valuation of themselves varies as much as the barometer, and is as much affected by outward causes.