Whenever a true theory appears, it will be its own evidence. Its test is, that it will explain all phenomena.

There comes a period of the imagination to each--a later youth--the power of beauty, the power of looks, of poetry.

The senses collect the surface facts of matter... It was sensation; when memory came, it was experience; when mind acted, it was knowledge; when mind acted on it as knowledge, it was thought.

There is no den in the wide world to hide a rogue.

We are as much strangers in nature, as we are aliens from God. We do not understand the notes of birds. The fox and the deer run away from us; the bear and tiger rend us. We do not know the uses of more than a few plants, as corn and the apple, the potato and the vine. Is not the landscape, every glimpse of which hath a grandeur, a face of him?

Shall I tell you the secret of the true scholar? It is this: every man I meet is my master in some point, and in that I learn of him.

Whatever you do, you need courage.