Music is perpetual, and only the hearing is intermittent.

Humor, however broad and genial, takes a narrower view than enthusiasm.

A truly good book teaches me better than to read it. I must soon lay it down, and commence living on its hint. What I began by reading, I must finish by acting.

As I love nature, as I love singing birds, and gleaming stubble, and flowing rivers, and morning and evening, and summer and winter, I love thee, my Friend.

A man who has to go to the village to get the news hasn't heard from himself in a long time.

He is not a true man of science who does not bring some sympathy to his studies, and expect to learn something by behavior as well as by application. It is childish to rest in the discovery of mere coincidences, or of partial and extraneous laws. The study of geometry is a petty and idle exercise of the mind, if it is applied to no larger system than the starry one. Mathematics should be mixed not only with physics but with ethics; that is mixed mathematics. The fact which interests us most is the life of the naturalist. The purest science is still biographical.

Whatever has not come under the sway of man is wild. In this sense original and independent men are wild - not tamed and broken by society.