The most important method of education always has consisted of that in which the pupil was urged to actual performance.

I am strongly drawn to a frugal life and am often oppressively aware that I am engrossing an undue amount of the labor of my fellow men.

... it is a welcome symptom in an age which is commonly denounced as materialistic, that it makes heroes of men whose goals lie wholly in the intellectual and moral sphere.

God does not care about our mathematical difficulties. He integrates empirically.

... mathematics ... affords the exact natural sciences a certain measure of certainty, to which without mathematics they could not attain.

Non-cooperation in military matters should be an essential moral principle for all true scientists ...

... a person who is religiously enlightened appears to me to be one who has, to the best of his ability, liberated himself from the fetters of his selfish desires and is preoccupied with thoughts, feelings, and aspirations to which he clings because of their superpersonal value.

I think and think for months and years. Ninety-nine times, the conclusion is false. The hundredth time I am right.

As to science, we may well define it for our purpose as "methodical thinking directed toward finding regulative connections between our sensual experiences."

Is it not a terrible thing to be forced by society to do things which all of us as individuals regard as abominable crimes?