To begin with its simplest if lowest aspect, pain is a punishment; and without importing any _a priori_ notions into the question, we find punishment to be a necessary element in the evolution of character. Punishment is a complex thing, and the tendency of civilization is to lay stress upon its corrective rather than its vindictive aspect. But we must remember that with uncivilized races this cannot be the case; and that pains and penalties, considered simply as retrospective vengeance for the past, have been historically, and in some cases still are, essential to our social development. Indeed, it is a shallow view that regards vengeance as a survival of savagery. Vengeance is intimately bound up with our sense of justice, and the true difference between the savage and the sage is that what the one eagerly inflicts upon his neighbour, the other would far more willingly inflict upon himself. Plato expressed this once for all when he said that the sinner who is punished is happier than the sinner who escapes scot free. We rightly shrink, as far as possible, from sitting in judgment on our fellow-men; but we feel none the less that our own ill deeds demand a penalty, which may vary from bodily suffering to interior shame, but which in one form or another must be endured before we can recover our self-respect. And self-respect is a necessary factor in all moral progress. Punishment, then, considered as vengeance, is a necessity for the social development of barbarous races; and though less obviously, quite as really for the personal progress of the civilized man. Now, without committing ourselves to the statement that suffering was introduced into the world by sin, which is not a Christian dogma, though it is often thought to be so, a vast amount of the suffering in the world is obviously punishment, and punishment of a very searching kind. For not only are obvious vices punished with remorse, and disease, and shame, but ignorance, impatience, carelessness, even mistakes of judgment are punished too, and that in a degree which we are apt to consider disproportionate; forgetful that consequences are God's commentaries, and this apparent disproportion may reflect light upon the real magnitude of what we often are too ready to consider trivial things.