Friendship is not going to stand the pressure of greatly great guidance for quite extensive.

Knowledge is power only if man knows what facts not to bother with.

The telephone is the greatest nuisance among conveniences, the greatest convenience among nuisances.

I sometimes suspect that half our difficulties are imaginary and that if we kept quiet about them they would disappear.

Every man of genius is considerably helped by being dead.

[History is] the story of the magnificent rear-guard action fought during several thousand years by dogma against curiosity.

When the last Puritan has disappeared from the earth, the man of science will take his place as a killjoy, and we shall be given the same old advice but for different reasons.