"Because the peculiarity of man is that his machinery for reaction on external things has involved an imaginative transcript of these things, which is preserved and suspended in his fancy; and the interest and beauty of this inward landscape, rather than any fortunes that may await his body in the outer world, constitute his proper happiness. By their mind, its scope, quality, and temper, we estimate men, for by the mind only do we exist as men, and are more than so many storage-batteries for material energy. Let us therefore be frankly human. Let us be content to live in the mind."

“Eternal vigilance is the price of knowledge.”

“American life is a powerful solvent. As it stamps the immigrant, almost before he can speak English, with an unmistakable muscular tension, cheery self-confidence and habitual challenge in the voice and eyes, so it seems to neutralize every intellectual element, however tough and alien it may be, and to fuse it in the native good-will, complacency, thoughtlessness, and optimism.”

“The soul, too, has her virginity and must bleed a little before bearing fruit.”

“It is not society's fault that most men seem to miss their vocation. Most men have no vocation.”

“Skepticism, like chastity, should not be relinquished too readily.”

“Perhaps the only true dignity of man is his capacity to despise himself.”