Judge a man's character by what he finds ridiculous.

The history of science is science itself; the history of the individual, the individual.

The dear good people don't know how long it takes to learn to read. I've been at it eighty years, and can't say yet that I've reached the goal.

Everything factual is, in a sense, theory. The blue of the sky exhibits the basic laws of chromatics. There is no sense in looking for something behind phenomena: they are theory.

The most damaging prejudice consists of banning any kind of investigation of nature.

The man with insight enough to admit his limitations comes nearest to perfection.

It is unpleasant to miss even the most trifling thing to which we have been accustomed.