All is to be doubted.

For each of us there is a set limit to our intellectual powers which we cannot pass.

Every man is indeed bound to do what he can to promote the good of others, and a man who is of no use to anyone is strictly worthless.

It's the familiar love-hate syndrome of seduction: "I don't really care what it is I say, I care only that you like it."

De omnibus dubitandum

Because reason...is the only thing that makes us men, and distinguishes us from the beasts, I would prefer to believe that it exists, in its entirety, in each of us.

I accept no principles of physics which are not also accepted in mathematics.