The first and the simplest emotion which we discover in the human mind is curiosity. By curiosity I mean whatever desire we have for, or whatever pleasure we take in, novelty. We see children perpetually running from place to place, to hunt out something new: they catch with great eagerness, and with very little choice, at whatever comes before them; their attention is engaged by everything, because everything has, in that stage of life, the charm of novelty to recommend it. But as those things, which engage us merely by their novelty, cannot attach us for any length of time, curiosity is the most superficial of all the affections; it changes its object perpetually; it has an appetite which is very sharp, but very easily satisfied; and it has always an appearance of giddiness, restlessness, and anxiety. Curiosity, from its nature, is a very active principle; it quickly runs over the greatest part of its objects, and soon exhausts the variety which is commonly to be met with in nature; the same things make frequent returns, and they return with less and less of any agreeable effect. In short, the occurrences of life, by the time we come to know it a little, would be incapable of affecting the mind with any other sensations than those of loathing and weariness, if many things were not adapted to affect the mind by means of other powers besides novelty in them, and of other passions besides curiosity in ourselves. These powers and passions shall be considered in their place. But, whatever these powers are, or upon what principle soever they affect the mind, it is absolutely necessary that they should not be exerted in those things which a daily and vulgar use have brought into a stale unaffecting familiarity. Some degree of novelty must be one of the materials in every instrument which works upon the mind; and curiosity blends itself more or less with all our passions.