Our teasing ourselves to recollect the names of places or persons we have forgotten, the love of riddles and of abstruse philosophy, are all illustrations of the same general principle of curiosity, or the love of intellectual excitement. Again, our impatience to be delivered of a secret that we know; the necessity which lovers have for confidants, auricular confession, and the declarations so commonly made by criminals of their guilt, are effects of the involuntary power exerted by the imagination over the feelings. Nothing can be more untrue, than that the whole course of our ideas, passions, and pursuits, is regulated by a regard to self-interest. Our attachment to certain objects is much oftener in proportion to the strength of the impression they make on us, to their power of riveting and fixing the attention, than to the gratification we derive from them. We are, perhaps, more apt to dwell upon circumstances that excite disgust and shock our feelings, than on those of an agreeable nature. This, at least, is the case where this disposition is particularly strong, as in people of nervous feelings and morbid habits of thinking. Thus the mind is often haunted with painful images and recollections, from the hold they have taken of the imagination. We cannot shake them off, though we strive to do it: nay, we even court their company; we will not part with them out of our presence; we strain our aching sight after them; we anxiously recall every feature, and contemplate them in all their aggravated colours. There are a thousand passions and fancies that thwart our purposes, and disturb our repose. Grief and fear are almost as welcome inmates of the breast as hope or joy, and more obstinately cherished. We return to the objects which have excited them, we brood over them, they become almost inseparable from the mind, necessary to it; they assimilate all objects to the gloom of our own thoughts, and make the will a party against itself. This is one chief source of most of the passions that prey like vultures on the heart, and embitter human life. We hear moralists and divines perpetually exclaiming, with mingled indignation and surprise, at the folly of mankind in obstinately persisting in these tormenting and violent passions, such as envy, revenge, sullenness, despair, etc. This is to them a mystery; and it will always remain an inexplicable one, while the love of happiness is considered as the only spring of human conduct and desires.[8]