case there is a feeling distinct and separate from the conception. The passage from doubt and agitation to tranquility and repose, conveys a satisfaction and pleasure to the mind. But take any other case. Suppose I see the legs and thighs of a person in motion, while some interpos'd object conceals the rest of his body. Here 'tis certain, the imagination spreads out the whole figure. I give him a head and shoulders, and breast and neck. These members I conceive and believe him to be possess'd of. Nothing can be more evident, than that this whole operation is perform'd by the thought or imagination alone. The transition is immediate. The ideas presently strike us. Their customary connexion with the present impression, varies them and modifies them in a certain manner, but produces no act of the mind, distinct from this peculiarity of conception. Let any one examine his own mind, and he will evidently find this to be the truth.
Secondly, Whatever may be the case, with regard to this distinct impression, it must be allow'd, that the mind has a firmer hold, or more steady conception of what it takes to be matter of fact, than of fictions. Why then look any farther, or multiply suppositions without necessity?
Thirdly, We can explain the causes of the firm conception, but not those of any separate impression. And not only so, but the causes of the firm conception exhaust the whole subject, and nothing is left to produce any other effect. An inference concerning a matter of fact is nothing but the idea of an object, that is frequently conjoin'd, or is associated with a present impression. This is the whole of it. Every part is requisite to explain, from analogy, the more steady conception; and nothing remains capable of producing any distinct impression.
Fourthly, The effects of belief, in influencing the passions and imagination, can all be explain'd from the firm conception; and there is no occasion to have recourse to any other principle. These arguments, with many others, enumerated
