Natural selection acts solely by accumulating slight successive favorable variations, it can produce no great or sudden modification; it can act only by very short steps.

I suppose you are two fathoms deep in mathematics, and if you are, then God help you. For so am I, only with this difference: I stick fast in the mud at the bottom, and there I shall remain.

Sympathy for the lowest animals is one of the noblest virtues with which man is endowed.

Whenever I have found that I have blundered, or that my work has been imperfected, and when I have been contemptuously criticised, and even when I have been overpraised, so that I have felt mortified, it has been my greatest comfort to say hundreds of times to myself that 'I have worked as hard as I could, and no man can do more than this.'

I am aware that the assumed instinctive belief in God has been used by many persons as an argument for his existence. The idea of a universal and beneficent Creator does not seem to arise in the mind of man, until he has been elevated by long-continued culture.

If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find no such case.

I must begin with a good body of facts and not from a principle (in which I always suspect some fallacy) and then as much deduction as you please.