Put the world's greatest philosopher on a plank that is wider than need be; if there is a precipe below, although his reason may convince him that he is safe, his imagination will prevail.

Curiosity is nothing more than vanity. More often than not we only seek knowledge to show it off.

In each action we must look beyond the action at our past, present, and future state, and at others whom it affects, and see the relations of all those things. And then we shall be very cautious.

[On vanity:] The nose of Cleopatra: if it had been shorter, the face of the earth would have changed.

Custom determines what is agreeable.

Something incomprehensible is not for that reason less real.

We sail within a vast sphere, ever drifting in uncertainty, driven from end to end.