Our belief at the beginning of a doubtful undertaking is the one thing that assures the successful outcome of any venture.

If an unusual necessity forces us onward, a surprising thing occurs. The fatigue gets worse up to a certain point, when, gradually or suddenly, it passes away and we are fresher than before!

The intellectual life of man consists almost wholly in his substitution of conceptual order for the perceptual order in which his experience originally comes.

Religious awe is the same organic thrill which we feel in a forest at twilight, or in a mountain gorge.

A good hypothesis in science must have other properties than those of the phenomenon it is immediately invoked to explain, otherwise it is not prolific enough.

...By far the most usual way of handling phenomena so novel that they would make for a serious rearrangement of our preconceptions is to ignore them altogether, or to abuse those who bear witness for them.

I will act as if I do make a difference.