Once your faith persuades you to believe what your intelligence declares absurd, beware, lest you likewise sacrifice your reason in the conduct of your life.

He who cannot shine by thought, seeks to bring himself into notice by a witticism.

God is a circle whose center is everywhere and circumference nowhere.

The system of Descartes... seemed to give a plausible reason for all those phenomena; and this reason seemed more just, as it is simple and intelligible to all capacities. But in philosophy, a student ought to doubt of the things he fancies he understands too easily, as much as of those he does not understand.

When one man speaks to another man who doesn't understand him, and when a man who's speaking no longer understands, it's metaphysics.

Common sense is not so common.

I would rather obey a fine lion, much stronger than myself, than two hundred rats of my own species.