will, it is plain the mind rests and terminates in that idea, which is contrary to the idea of infinity, which consists in a supposed endless progression. And therefore I think it is, that we are so easily confounded, when we come to argue and reason about infinite space or duration, &c.: because the parts of such an idea not being perceived to be, as they are, inconsistent, the one side or other always perplexes, whatever consequences we draw from the other; as an idea of motion not passing on would perplex any one, who should argue from such an idea, which is not better than an idea of motion at rest: and such another seems to me to be the idea of a space, or (which is the same thing) a number infinite, i. e. of a space or number which the mind actually has, and so views and terminates in; and of a space or number which, in a constant and endless enlarging and progression, it can in thought never attain to. For how large soever an idea of space I have in my mind, it is no larger than it is that instant that I have it, though I be capable the next instant to double it, and so on in infinitum: for that alone is infinite which has no bounds; and that the idea of infinity, in which our thoughts can find none.
Number affords us the clearest idea of infinity.§ 9. But of all other ideas, it is number, as I have said, which I think furnishes us with the clearest and most distinct idea of infinity we are capable of. For even in space and duration, when the mind pursues the idea of infinity, it there makes use of the ideas and repetitions of numbers, as of millions and millions of miles, or years, which are so many distinct ideas, kept best by number from running into a confused heap, wherein the mind loses itself; and when it has added together as many millions, &c. as it pleases, of known lengths of space or duration, the clearest idea it can get of infinity is the confused incomprehensible remainder of endless addible numbers, which affords no prospect of stop or boundary.
