A debate between the virtue of self-interest and social conceptions of morality emerged in the seventeenth century. Aspects of the historical narrative of these ideas have been touched on by Franco Venturi (1971), Albert O. Hirschman (1977), Pierre Force (2003) and Eric MacGilvray (2011), among others, but broadly one can recognise two camps which ossified during the eighteenth century: those who saw public utility in self-interest emerge from the positive externalities of commerce, and those who had serious concerns over the political implications of entangling commerce and virtue. This chapter locates, primarily, Rousseau within this debate, and by looking at how his moral philosophy interacts with his political thought, argues that he is distinct from contemporary thinkers (in particular, Adam Smith), but in an often confused way: while some have been tempted to view Rousseau as a republican moralist, he is in fact a philosopher of the political and social good of self-interest.

To make this argument, this chapter opens with a brief exploration of Adam Smith's position and the ‘impartial spectator’, arguing that Smith is a moral sentimentalist and moral rationalist.

That is to say, first, moral ideas are born from moral sentiments, and these truths are discoverable through reason. The chapter then examines the source of morality and moral action in Rousseau's thought. It is argued that he is not a moral realist and instead agrees with Hobbes that morality comes to exist only with society (although he denies that this lack of morality is the equivalent to immorality – he is not a moral realist) (Second Discourse 1997a: 151/OC III: 153). Specifically, morality emerges due to perfectibility – the confluence of pity and reason result in moral concepts being developed. Thus, it is shown that Rousseau is a moral rationalist. However, this position is complicated by Rousseau's belief that moral rationalism is, by itself, incapable of ensuring moral actions. The chapter goes on to demonstrate that the source of this problem is, in fact, reason itself. He is, therefore, a moral rationalist in terms of source, but is sceptical of reason as a moral motivator.

How Rousseau solves this problem is the topic of the second part of this chapter.