There are people who think that everything one does with a serious face is sensible.

There is no more important rule of conduct in the world than this: attach yourself as much as you can to people who are abler than you and yet not so very different that you cannot understand them.

Nothing puts a greater obstacle in the way of the progress of knowledge than thinking that one knows what one does not yet know.

Imagine the world so greatly magnified that particles of light look like twenty-four-pound cannon balls.

There exists a species of transcendental ventriloquism by means of which men can be made to believe that something said on earth comes from Heaven.

What most clearly characterizes true freedom and its true employment is its misemployment.

We have no words for speaking of wisdom to the stupid. He who understands the wise is wise already.