no original perversity
Rousseau is laying out his fundamental beliefs about the natural goodness of man and the way that amour-propre becomes corrupting. The idea is developed even more fully in Rousseau's Letter to Beaumont (1763) where he explains his overall purpose in Emile: "The fundamental principle of all morality, that on which I have reasoned in all my writings, and which I explained in the last, with all the perspicuity I was master of, is this: that man is naturally good; that he loves justice and order; that there is no original perversity in the human heart, and that the first emotions of nature are always right. I have shewn that the only passion which is born with man, to wit, self-love [amour de soi], is in itself indifferent either to good or evil; that it becomes good or evil only by accident, and according to the circumstances in which it is displayed. I have shewn that none of the vices imputed to the human heart are natural to it; I have described the manner in which they arise, have traced as it were, their genealogy, and shewn the manner in which, by a successive deviation from their original goodness, mankind are become what they are." Letter to Christophe de Beaumont, 1767 translation, p. 249; OC IV, p. 935.