Eternal vigilance is the price of knowledge.

Matters of religion should never be matters of controversy. We neither argue with a lover about his taste, nor condemn him, if we are just, for knowing so human a passion.

To be bewitched is not to be saved, though all the magicians and aesthetes in the world should pronounce it to be so.

Half our standards come from our first masters, and the other half from our first loves.

The line between what is known scientifically and what has to be assumed in order to support knowledge is impossible to draw. Memory itself is an internal rumour.

By "essence" I understand a universal, of any degree of complexity and definition, which may be given immediately, whether to sense or to thought.... This object of pure sense or pure thought, with no belief superadded, an object inwardly complete and individual, but without external relations or physical status, is what I call an essence.

There is no greater stupidity or meanness than to take uniformity for an ideal.