The education which in the ideal state is to be given to children is represented by him, indeed, as the evolution from the sensations of pleasure and pain to the perception of virtue and vice. “Pleasure and pain,” he says,[8] “I maintain to be the first perceptions of children, and I say that they are the forms under which virtue and vice are originally present to them. As to wisdom and true and fixed opinions, happy is the man who acquires them, even when declining in years; and he who possesses them, and the blessings which are contained in them, is a perfect man. Now I mean by education that training which is given by suitable habits to the first instincts of virtue in children; when pleasure and friendship and pain and hatred are rightly implanted in souls not yet capable of understanding the nature of them, and who find them, after they have attained reason, to be in harmony with her. This harmony of the soul, when perfected, is virtue; but the particular training in respect of pleasure and pain which leads you always to hate what you ought to hate, and love what you ought to love, from the beginning to the end, may be separated off, and, in my view, will be rightly called education.” In the Republic, Plato theorizes at great length upon a possible selection and training of children, which rests for its basis upon a too pronounced physical assumption, so that one in reading certain passages might easily fancy that he was considering the production of a superior breed of colts, and that the soul was the product of material forces only; but the fifth book, which contains these audacious speculations, may fairly be taken in the spirit in which Proudhon is said to have thrown out some of his extravagant assertions,—he expected to be beaten down in his price.