It has always been desirable to tell the truth, but seldom if ever necessary.

Enthusiasm moves the world.

Ask with urgency and passion.

Science preceded the theory of science, and is independent of it. Science preceded naturalism, and will survive it.

Though the parallel is not complete, it is safe to say that science will never touch them unaided by its practical applications. Its wonders may be catalogued for purposes of education, they may be illustrated by arresting experiments, by numbers and magnitudes which startle or fatigue the imagination but they will form no familiar portion of the intellectual furniture of ordinary men unless they be connected, however remotely, with the conduct of ordinary life.

He has only half learned the art of reading who has not added to it the more refined art of skipping and skimming.

Biography should be written by an acute enemy.