As I came home through the woods with my string of fish, trailing my pole, it being now quite dark, I caught a glimpse of a woodchuck stealing across my path, and felt a strange thrill of savage delight, and was strongly tempted to seize and devour him raw; not that I was hungry then, except for that wildness which he represented.

Pray, for what do we move ever but to get rid of our furniture, our exuviæ; at last to go from this world to another newly furnished, and leave this to be burned?

What is peculiar in the life of a man consists not in his obedience, but his opposition, to his instincts. In one direction or another he strives to live a supernatural life.

Take long walks in stormy weather or through deep snows in the fields and woods, if you would keep your spirits up. Deal with brute nature. Be cold and hungry and weary.

One is not born into the world to do everything but to do something.

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.

What we need to know in any case is very simple.