Is a man what he seems to the astronomer, a tiny lump of impure carbon and water crawling impotently on a small and unimportant planet? Or is he what he appears to Hamlet? Is he perhaps both as once?

All serious innovation is only rendered possible by some accident enabling unpopular persons to survive.

Dr. Arnold . . . the admired reformer of public schools, came across some cranks who thought it a mistake to flog boys. Anyone reading his outburst of furious indignation against this opinion will be forced to the conclusion that he enjoyed inflicting floggings.

The skill of the politician consists in guessing what people can be brought to think advantageous to themselves; the skill of the expert consists in calculating what really is advantageous, provided people can be brought to think so.

Physics, owing to the simplicity of its subject matter, has reached a higher state of development than any other science.

My whole religion is this: do every duty, and expect no reward for it, either here or hereafter.

What science cannot discover, mankind cannot know.