Now if we compare these two cases, that of a person, who has very strong motives of interest or safety to forbear any action, and that of another, who lies under no such obligation, we shall find, according to the philosophy explained in the foregoing book, that the only known difference betwixt them lies in this, that in the former case we conclude from past experience, that the person never will perform that action, and in the latter, that he possibly or probably will perform it.