If reason be a gift of Heaven, and we can say as much of faith, Heaven has certainly made us two gifts not only incompatible, but in direct contradiction to each other. In order to solve the difficulty, we are compelled to say either that faith is a chimera or that reason is useless.

A thing is not proved just because no one has ever questioned it. What has never been gone into impartially has never been properly gone into. Hence scepticism is the first step toward truth. It must be applied generally, because it is the touchstone.

If there are one hundred thousand damned souls for one saved soul, the devil has always the advantage without having given up his son to death.

The man who first pronounced the barbarous word God ought to have been immediately destroyed.

I like better for one to say some foolish thing upon important matters than to be silent. That becomes the subject of discussion and dispute, and the truth is discovered.

I picture the vast realm of the sciences as an immense landscape scattered with patches of dark and light. The goal towards which we must work is either to extend the boundaries of the patches of light, or to increase their number. One of these tasks falls to the creative genius; the other requires a sort of sagacity combined with perfectionism.

My ideas are my whores.