If we then inquire for the character of this emotion, it must be where the unexpected object or event produceth less violent effects. And while the mind remains sensible of pleasure and pain, is it not natural to suppose, that surprise, like wonder, should have an invariable character? I am inclined however to think, that surprise has no invariable character, but assumes that of the object which raises it. Wonder is the gratification of a natural principle, and upon that account must be pleasant. There, novelty is the capital circumstance, which, for a time, is intitled to possess the mind entirely in one unvaried tone. The unexpected appearance of an object, seems not equally intitled to produce an emotion distinguishable from the emotion, pleasant or painful, that is produced by the object in its ordinary appearance. It ought not naturally to have any effect, other than to swell that emotion, by making it more pleasant or more painful than it commonly is. And this conjecture is confirmed by experience, as well as by language, which is built upon experience. When a man meets a friend unexpectedly, he is said to be agreeably surprised; and when he meets an enemy unexpectedly, he is said to be disagreeably surprised. It appears then, that the sole effect of surprise is to swell the emotion raised by the object. And this effect can be clearly explained. A tide of connected perceptions, glides gently into the mind, and produceth no perturbation. An object on the other hand breaking in unexpectedly, sounds an alarm, rouses the mind out of its calm state, and directs its whole attention upon the object, which, if agreeable, becomes doubly so. Several circumstances concur to produce this effect. On the one hand, the agitation of the mind and its keen attention, prepare it in the most effectual manner for receiving a deep impression. On the other hand, the object by its sudden and unforeseen appearance, makes an impression, not gradually as expected objects do, but as at one stroke with its whole force. The circumstances are precisely similar, where the object is in itself disagreeable. The pleasure of novelty is easily distinguished from that of variety. To produce the latter, a plurality of objects is necessary. The former arises from a circumstance found in a single object. Again, where objects, whether coexistent or in succession, are sufficiently diversified, the pleasure of variety is complete, though every single object of the train be familiar. But the pleasure of novelty, directly opposite to familiarity, requires no diversification.