When I say, I intend to inquire into the efficient cause of sublimity and beauty, I would not be understood to say, that I can come to the ultimate cause. I do not pretend that I shall ever be able to explain why certain affections of the body produce such a distinct emotion of mind, and no other; or why the body is at all affected by the mind, or the mind by the body. A little thought will show this to be impossible. But I conceive, if we can discover what affections of the mind produce certain emotions of the body; and what distinct feelings and qualities of body shall produce certain determinate passions in the mind, and no others, I fancy a great deal will be done; something not unuseful towards a distinct knowledge of our passions, so far at least as we have them at present under our consideration. This is all, I believe, we can do. If we could advance a step farther, difficulties would still remain, as we should be still equally distant from the first cause. When Newton first discovered the property of attraction, and settled its laws, he found it served very well to explain several of the most remarkable phenomena in nature; but yet, with reference to the general system of things, he could consider attraction but as an effect, whose cause at that time he did not attempt to trace. But when he afterwards began to account for it by a subtle elastic ether, this great man (if in so great a man it be not impious to discover anything like a blemish) seemed to have quitted his usual cautious manner of philosophizing; since, perhaps, allowing all that has been advanced on this subject to be sufficiently proved, I think it leaves us with as many difficulties as it found us. That great chain of causes, which, linking one to another, even to the throne of God himself, can never be unravelled by any industry of ours. When we go but one step beyond the immediate sensible qualities of things, we go out of our depth. All we do after is but a faint struggle, that shows we are in an element which does not belong to us. So that when I speak of cause, and efficient cause, I only mean certain affections of the mind, that cause certain changes in the body; or certain powers and properties in bodies, that work a change in the mind. As, if I were to explain the motion of a body falling to the ground, I would say it was caused by gravity; and I would endeavor to show after what manner this power operated, without attempting to show why it operated in this manner: or, if I were to explain the effects of bodies striking one another by the common laws of percussion, I should not endeavor to explain how motion itself is communicated. SECTION II. ASSOCIATION.