Every human being is distinguished from every other human being both numerically and characteristically. He must be numerically distinct by the supposition, or he would not be another individual, but the same. There is, however, no contradiction in supposing two individuals to possess the same absolute properties: but then these original properties must be differently modified afterwards from the necessary difference of their situations, unless we conceive them both to occupy the same relative situation in two distinct systems, corresponding exactly with each other. In fact, every one is found to differ essentially from every one else; if not in original qualities, in the circumstances and events of their lives, and consequently in their ideas and characters. In thinking of a number of individuals, I conceive of them all as differing in various ways from one another as well as from myself. They differ in size, in complexion, in features, in the expression of their countenances, in age, in occupation, in manners, in knowledge, in temper, in power. It is this perception or apprehension of their real differences that first enables me to distinguish the several individuals of the species from each other, and that seems to give rise to the most obvious idea of individuality, as representing, first, positive number, and, secondly, the sum of the differences between one being and another, as they really exist, in a greater or less degree in nature, or as they would appear to exist to an impartial spectator, or to a perfectly intelligent mind. But _I_ am not in reality more different from others than any one individual is from any other individual, neither do I in fact suppose myself to differ really from them otherwise than as they differ from each other. What is it then that makes the difference seem greater _to me_, or that makes me feel a greater change in passing from my own idea to that of another person, than in passing from the idea of another person to that of any one else? Neither my existing as a separate being, nor my differing from others, is of itself sufficient to account for the idea of self, since I might equally perceive others to exist and compare their actual differences without ever having this idea.