A tree nowhere offers a straight line or a regular curve, but who doubts that root, trunk, boughs, and leaves embody geometry?

Degree is much: the whole Atlantic might be lukewarm and never boil us a potato.

Boundaries which mark off one field of science from another are purely artificial, are set up only for temporary convenience. Let chemists and physicists dig deep enough, and they reach common ground.

No gun is perfectly true. So the marksman, that he may hit the bull's-eye, points elsewhere.

Educated folk keep to one another's company too much, leaving other people much like milk skimmed of its cream.

Dumbness and silence are two different things.

Doubt is the beginning, not the end, of wisdom.