Let nobody be afraid of true freedom of thought. Let us be free in thought and criticism; but, with freedom, we are bound to come to the conclusion that science is not antagonistic to religion, but a help to it.

Can you measure it? Can you express it in figures? Can you make a model of it? If not, your theory is apt to be based more upon imagination than upon knowledge.

When you are face to face with a difficulty, you are up against a discovery.

I believe that the more thoroughly science is studied, the further does it take us from anything comparable to atheism.

We all confidently believe that there are at present, and have been from time immemorial, many worlds of life besides our own. . . . [This] may seem wild, and visionary; all I maintain is that it is not unscientific.

Quaternions came from Hamilton after his really good work had been done, and though beautifully ingenious, have been an unmixed evil to those who have touched them in any way.

When you cannot measure, your knowledge is meager and unsatisfactory.