It was in 1748, at the age of 36, that he made the acquaintance, at the house of Mde. d’Epinay, of the editors of the _Encyclopédie_, D’Alembert and Diderot, who engaged him to write articles on music and upon other subjects in that first of comprehensive dictionaries. His first independent appearance in literature was in his essay on the question, “Whether the progress of science and of the arts has been favourable to the morals of mankind,” in which paradoxically he maintains the negative. It was the eloquence, we must suppose, rather than the reasoning, which gained him the prize awarded by the Académie of Dijon. His next production--a more important one--was his _Discours sur l’Inegalité parmi les Hommes_ (“Discourse upon Inequality amongst Men”). In this treatise--the prelude to his more developed _Contrat Social_--Rousseau affirms the paradox of the _natural_ school, as it may be termed, which alleged the state of nature--the life of the uncivilised man--to be the ideal condition of the species. His thesis that all men are born with equal rights takes a much more defensible position. In this _Discours_ diet is assigned its due importance in relation to the welfare of communities.
The romance of _Julie: ou la Nouvelle Héloise_, which excited an unusual amount of interest, appeared in 1759. _Emile: ou de l’Education_, was given to the world three years later. It is the most important of his writings. In the education of Emile, or Emilius, he propounds his ideas upon one of the most interesting subjects which can engage attention--the right training of the young. The earlier part of the book is almost altogether admirable and useful. The later portion is more open to criticism, although not upon the grounds upon which was founded the hostility of the authorities of the day who unjustly condemned the book as irreligious and immoral. Rousseau begins with laying down the principles of a new and more rational method of rearing infants, agreeing, in many particulars, with the system of his predecessor, Locke. At least some of his protests against the unnatural treatment of children were not altogether in vain. Mothers in fashionable ranks of life began to recognise the mischief arising from the common practice of putting their infants out to nurse in place of suckling them themselves. They began also to abandon the absurd custom of confining their limbs in mummy-like bandages. Nor, though long in bearing adequate fruit, were his denunciations of the barbarous severity of parents and schoolmasters without some result. He insists upon the incalculable evils of inoculating the young, according to the almost universal custom, with superstitious beliefs and fancies which grow with the growth of the recipient until they become radically fixed in the mind as by a natural development. Most important of all his innovations in education, and certainly the most heretical, is his recommendation of a pure dietary.