Men are made uneasy; they flinch; they cannot bear the sudden light; a general restlessness supervenes; the face of society is disturbed, or perhaps convulsed; old interests and old beliefs have been destroyed before new ones have been created. These symptoms are the precursors of revolution; they have preceded all the great changes through which the world has passed.

First doubt, then inquire, then discover. This has been the process with all our great thinkers.

The faculty of art is to change events; the faculty of science is to foresee them. The phenomena with which we deal are controlled by art; they are predicted by science.

Sir, the slowness of genius is hard to bear, but the slowness of mediocrity is insufferable.

He who knows most believes the least.

The duty of a philosopher is clear. He must take every pain to ascertain the truth; and, having arrived at a conclusion, he should noise it abroad far and wide, utterly regardless of what opinions he shocks.

The clergy, with a few honorable exceptions, have in all modern countries been the avowed enemies of the diffusion of knowledge, the danger of which to their own profession they, by a certain instinct, seem always to have perceived.