A state of belief is when a man has a habit, knows he has it, and is satisfied with having it. [—] A man believes in a proposition when he is, and knows he is, and is satisfied to be in such a state that he will act on every pertinent occasion in such ways as would result as consequences of that proposition, taken in connected with other propositions he believes.
From an alternate, probably discarded draft
http://www.commens.org/dictionary/entry/quote-humes-argument-against-miracles-and-idea-natural-law-hume-4