...we ought not meanwhile to make use of doubt in the conduct of life.

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.

I am thing that thinks: that is, a things that doubts,affirms, denies, understands a few things, is ignorant of many things, is willing, is unwilling, and also which imagines and has sensory perceptions.

And I shall always hold myself more obliged to those by whose favour I enjoy uninterrupted leisure than to any who might offer me the most honourable positions in the world.