“Our knowledge is the amassed thought and experience of innumerable minds.”

“That which we are, we shall teach, not voluntarily, but involuntarily. Thoughts come into our minds by avenues which we never left open, and thoughts go out of our minds through avenues which we never voluntarily opened.”

“Do you think the porter and the cook have no anecdotes, no experiences, no wonders for you? The walls of their minds are scrawled all over with thoughts. They shall one day bring a lantern and read the inscriptions.”

“There are books . . . which rank in our life with parents and lovers and passionate experiences.”

“Every revolution was first a thought in one man's mind, and when the same thought occurs to another man, it is the key to that era.”

“A man should learn to detect and watch that gleam of light which flashes across his mind from within, more than the lustre of the firmament of bards and sages. Yet he dismisses without notice his thought, because it is his. In every work of genius we recognize our own rejected thoughts: they come back to us with a certain alienated majesty.”

“I hate this shallow Americanism which hopes to get rich by credit, to get knowledge by raps on midnight tables, to learn the economy of the mind by phrenology, or skill without study, or mastery without apprenticeship.”