There are three agents of education--Nature, men, and circumstances. “The constitutional exertion of our organs and faculties is the education of nature: the uses we are taught to make of that exertion constitute the education given us by men; and in the acquisitions made by our own experience on the objects that surround us consists our education from circumstances” (17: i, p. 10). Of these, the first does not depend on ourselves, the second depends on us, and the third is under our power of control to a certain extent. So in order to secure the harmony of these three it is to the first that we must adjust the two others. Therefore, Nature--i. e., the law of the psychophysical organism of the child itself--must be the true nurse and trainer of the child. The function of an educator is simply to administer her oracle. Then let us hear some of the oracles of Nature: First of all: “Nature requires children to be children before they are men”; and “by endeavoring to pervert this order we produce forward fruits, that have neither maturity nor taste, and will not fail soon to wither or corrupt” (17: i, p. 108). Beware of forcing upon the child any adult standard, for “every age, every state of life has its peculiar degrees of perfection, a kind of maturity peculiar to itself” (17: i, p. 246). The end of life is in itself; our aim is to live our life to the full; and this is happiness. “To live is not merely to breathe; it is to act, to make a proper use of our organs, our senses, our faculties, and of all those parts of the human frame which contribute to the consciousness of our existence. The man who has lived most is not he who has survived the greatest number of years, but he who has experienced most of life. A man may be buried at a hundred years of age who died in his cradle. Such a one would have been a gainer by dying young, at least if he had lived, in our sense of the word, till the time of his decease” (17: i, pp. 18-19). Therefore, let the child live its own present life, which is the only reality to him; “let us promote the happiness of man in every stage of life.” From this viewpoint Rousseau directs his indignation upon the current mode of education. He says: “What can we think, then, of that barbarous method of education, by which the present is sacrificed to an uncertain future, by which a child is laid under every kind of restraint, and is made miserable, by way of preparing him for we know not what pretended happiness, which there is reason to believe he may never live to enjoy? Supposing it not unreasonable in its design, how can we see, without indignation, the unhappy innocents subjected to a yoke of insupportable rigor and condemned like galley-slaves to continual labor, without being assured that such mortifications and restrictions will ever be of any service to them? The age of cheerfulness and gayety is spent in the midst of tears, punishments, threats, and slavery” (17: i, pp. 85-86).