In order to explain these differences, it would be an endless work to examine every emotion and passion in particular. We must be satisfied at present with some general views. And with respect to emotions, which are quiescent and not productive of desire, their growth and decay are easily explained. An emotion caused by an external object, cannot naturally take longer time to arrive at perfection, than is necessary for a leisurely survey. Such emotion also must continue long stationary, without any sensible decay; a second or third view of the object being nearly as agreeable as the first. This is the case of an emotion produced by a fine prospect, an impetuous river, or a towering hill. While a man remains the same, such objects ought to have the same effect upon him. Familiarity, however, hath an influence here, as it hath every where. Frequency of view, after short intervals especially, weans the mind gradually from the object, which at last loses all relish. The noblest object in the material world, a clear and serene sky, is quite disregarded, unless perhaps after a course of bad weather. An emotion raised by human virtues, qualities, or actions, may grow imperceptibly by reiterated views of the object, till it become so vigorous as to generate desire. In this condition it must be handled as a passion. As to passion, I observe first, that when nature requires a passion to be sudden, it is commonly produced in perfection. This is frequently the case of fear and of anger. Wonder and surprise are always produced in perfection. Reiterated impressions made by their cause, exhaust these passions in place of inflaming them. This will be explained afterward[34]. In the next place, when a passion hath for its foundation an original propensity peculiar to some men, it generally comes soon to perfection. The propensity, upon representing a proper object, is immediately enlivened into a passion. This is the case of pride, of envy, and of malice.