Exercise is labor without weariness.

Language is only the instrument of science, and words are but the signs of ideas.

Excellence in any department can be attained only by the labor of a lifetime; it is not to be purchased at a lesser price.

Mankind have a great aversion to intellectual labor; but even supposing knowledge to be easily attainable, more people would be content to be ignorant than would take even a little trouble to acquire it

Such is the constitution of man that labor may be styled its own reward; nor will any external incitements be requisite, if it be considered how much happiness is gained, and how much misery escaped, by frequent and violent agitation of the body

I write about myself with the same pencil and in the same exercise book as about him. It is no longer I, but another whose life is just beginning.