..all arguments concerning existence are founded on the relation of cause and effect; that our knowledge of that relation is derived entirely from experience; and all our experimental conclusions proceed upon the supposition that the future will be conformable to the past. .... Without the influence of custom, we should be entirely ignorant of every matter of fact beyond what is immediately present to the memory and senses.

Anything that is conceivable is possible.

The mind is a kind of theater, where several perceptions successively make their appearence; pass, re-pass, glide away, and mingle in an infinite variety of postures and situations.

No man ever threw away life while it was worth keeping.

Where ambition can cover its enterprises, even to the person himself, under the appearance of principle, it is the most incurable and inflexible of passions

..when, in my philosophical disquisitions, I deny a providence and a future state, I undermine not the foundations of society, but advance principles, which they themselves, upon their own topics, if they argue consistently, must allow to be solid and satisfactory.

Interest is the barometer of the state.