This article undertakes a comparative study of the conjectural histories of Jean-Jacques Rousseau and Adam Ferguson, focusing on the convergences in the moral and political ideals expressed and grounded in these histories. In comparison with Scots like Adam Smith and John Millar, the conjectural histories of Ferguson and Rousseau follow a similar historical trajectory as regards the development and progress of commercial, political and cultural arts. However, their assessment of the moral progress of humanity does not, or in a much (...) more limited way than in Smith and Millar, correlate with this trajectory. Rousseau and Ferguson see a candour and vigour in savage and barbarian societies that is much less easily supported by the complex socio-economic framework of modern, commercial societies. It is argued that the convergences in their conjectural histories arise from a similar fusion of these histories with Stoic and republican perspectives. While Rousseau and Ferguson do not see history as cyclical, they think that the forces that push towards moral decline are strong and can, on the political level, only be countered by firm republican policies. Furthermore, their shared Stoic ideal of the life lived according to nature informs their solutions for modern societies. (shrink)