But, _secondly_,'tis equally obvious in this species of reasoning, that if the transference of the past to the future were founded merely on a conclusion of the understanding, it could never occasion any belief or assurance. When we transfer contrary experiments to the future, we can only repeat these contrary experiments with their particular proportions; which could not produce assurance in any single event upon which we reason, unless the fancy melted together all those images that concur, and extracted from them one single idea or image, which is intense and lively in proportion to the number of experiments from which it is derived, and their superiority above their antagonists. Our past experience presents no determinate object; and as our belief, however faint, fixes itself on a determinate object, 'tis evident that the belief arises not merely from the transference of past to future, but from some operation of the _fancy_ conjoined with it. This may lead us to conceive the manner in which that faculty enters into all our reasonings. I shall conclude this subject with two reflections which may deserve our attention. The _first_ may be explained after this manner: When the mind forms a reasoning concerning any matter of fact, which is only probable, it casts its eye backward upon past experience, and, transferring it to the future, is presented with so many contrary views of its object, of which those that are of the same kind uniting together and running into one act of the mind, serve to fortify and enliven it. But suppose that this multitude of views or glimpses of an object proceeds not from experience, but from a voluntary act of the imagination; this effect does not follow, or, at least, follows not in the same degree. For though custom and education produce belief by such a repetition as is not derived from experience, yet this requires a long tract of time, along with a very frequent and _undesigned_ repetition. In general we may pronounce, that a person, who would _voluntarily_ repeat any idea in his mind, though supported by one past experience, would be no more inclined to believe the existence of its object, than if he had contented himself with one survey of it. Beside the effect of design, each act of the mind, being separate and independent, has a separate influence, and joins not its force with that of its fellows. Not being united by any common object producing them, they have no relation to each other; and consequently make no transition or union of forces. This phenomenon we shall understand better afterwards.