Rousseau fifth lecture
A. Coda to the Discourse (pp. 135-end) picks up two themes:
1. The changeability of human individuals: "the human race of one age is not the human race of another age" (p. 135). Note the use of "nature" below: "how the soul and the human passions through imperceptible degeneration change, so to speak, their nature." "Nature" here means something like "what [the soul and the human passions] are like." Compare below, where he speaks of "artificial men and factitious passions, which are the product of all men's new relations, and which have no foundation in nature." Here "nature" stands in opposition to the idea of something artificial. Using "nature" and "natural" in the first of these ways, Rousseau's thought is that human nature has changed under the impact of sociological changes. Using it the other way, his thought is that human beings are no longer natural beings. And note that it requires a step outside the pure animal way of life for human beings (in the moral/metaphysical sense, as opposed to the biological sense) to be on the scene at all. One might say there's no such thing as something that's both human (in the moral/metaphysical sense) and natural (in the sense that's opposed to "artificial"). Alternatively (same thought): human nature is essentially indeterminate, including potentialities that require determinate social arrangements for their actualization (so that an actual human being is necessarily partly artificial).
2. The degeneracy of "civilized" life and the individuals who live it. Note the stress on inauthenticity ("everything is reduced to appearances," p. 136; below "we have only façades, deceptive and frivolous"). Given the view that this is the inevitable result of being a normal member of contemporary society, what life-plan would make sense for Rousseau? That of an outsider or misfit.
B. Where does this leave us? In the Discourse Rousseau evidently sees degeneration as inevitable, so he has an unqualified pessimism about the possibilities for human beings: we can't become human, in a more than merely biological sense, without starting on the downward slide he describes. But, granting his thought that social arrangements make human individuals into what they are, we can raise the question: could there be social arrangements (more advanced than the family groupings of the Discourse's golden epoch; including political institutions) that would frame a way of life in which human beings could satisfactorily actualize their moral/metaphysical potential, living freely and on equal terms? In his later work, The Social Contract, Rousseau (in effect) raises this question, and answers "Yes." The specifics of his proposal don't matter for us. The point is that his basic thought that human individuals are socially constituted can be separated from the pessimism of the Discourse; the basic thought allows for a project of devising better social and political arrangements than, in the Discourse, Rousseau sees as historically inevitable.