Here at any rate, Rousseau made no mistake. Had Emile been free to choose, this is precisely the book he would have chosen, though for less philosophical reasons; and the very fact that it fits Rousseau’s scheme of education is a proof that the scheme is sound. Robinson Crusoe, alone on his island, with neither house nor tools, gradually providing for his needs; it is Rousseau’s allegory of the triumph of man, and failure of civilisation. Emile cannot understand this yet, but the book will be a touchstone for his taste and judgment, and serve him and his tutor as a text for all their talk on the natural sciences. The boy’s interest is wholly practical; but it stimulates “the _real_ castle-building of that happy age when we know no other happiness than necessity and freedom”. Of free and imaginative castle-building, Rousseau has no notion, but Emile will know his Robinson Crusoe all the better, if he is allowed to act the story.