Fancy, when once brought into religion, knows not where to stop. It is like one of those fiends in old stories which any one could raise, but which, when raised, could never be kept within the magic circle.

Vices and frailties correct each other, like acids and alkalies. If each vicious man had but one vice, I do not know how the world could go on.

As an exercise of the reasoning faculties, pure mathematics is an admirable exercise, because it consists of reasoning alone and does not encumber the student with any exercise of judgment.

Controversy, though always an evil in itself, is sometimes a necessary evil.

Everyone wishes to have truth on his side, but not everyone wishes to be on the side of truth.

Of metaphors, those generally conduce most to energy or vivacity of style which illustrate an intellectual by a sensible object.

Even supposing there were some spiritual advantage in celibacy, it ought to be completely voluntary.