Page:Treatise of Human Nature (1888).djvu/129

109 As to the influence of contiguity and resemblance, we may observe, that if the contiguous and resembling object be comprehended in this system of realities, there is no doubt but these two relations will assist that of cause and effect, and infix the related idea with more force in the imagination. This I shall enlarge upon presently. Mean while I shall carry my observation a step farther, and assert, that even where the related object is but feign'd, the relation will serve to enliven the idea, and encrease its influence. A poet, no doubt, will be the better able to form a strong description of the Elysian fields, that he prompts his imagination by the view of a beautiful meadow or garden; as at another time he may by his fancy place himself in the midst of these fabulous regions, that by the feign'd contiguity he may enliven his imagination.

But tho' I cannot altogether exclude the relations of resemblance and contiguity from operating on the fancy in this manner, 'tis observable that, when single, their influence is very feeble and uncertain. As the relation of cause and effect is requisite to persuade us of any real existence, so is this persuasion requisite to give force to these other relations. For where upon the appearance of an impression we not only feign another object, but likewise arbitrarily, and of our mere good-will and pleasure give it a particular relation to the impression, this can have but a small effect upon the mind; nor is there any reason, why, upon the return of the same impression, we shou'd be determin'd to place the same object in the same relation to it. There is no manner of necessity for the mind to feign any resembling and contiguous objects; and if it feigns such, there is as little necessity for it always to confine itself to the same, without any difference or variation. And indeed such a fiction is founded on so little reason, that nothing but pure caprice can determine the mind to form it; and that principle being fluctuating and uncertain, 'tis impossible it can ever operate with any considerable degree of force and constancy. The mind forsees