In fact writing a computer program is a pretty good way to summarize knowledge about any set of rules. - Richard Dawkins

The successful scientist and the raving crank are separated by the quality of their inspirations. But I suspect that this amounts, in practice, to a difference, not so much in ability to notice analogies as in ability to reject foolish analogies and pursue helpful ones.

... you need more than luck to navigate successfully through a thousand sieves in succession.

Darwin, however, saw his doubts as a challenge to go on thinking, not a welcome excuse to give up.