Adam Smith's major works are widely thought to constitute a deliberate though implicit rebuttal to the critique of life in modern commercial societies that Rousseau presented in the Discourse on Inequality. This article examines Smith's few explicit references to Rousseau, all of which denigrate him in ways that Smith must have known are unsupported at best and insupportable at worst. The analysis focuses on the only topic that elicited a specific substantive criticism of Rousseau: the origin of languages. Both authors seriously investigated this topic, but in strikingly different ways. Rousseau's analysis of the evolution of language is deeper and more philosophically ambitious than Smith's. 'I his may help to explain why Smith mocked Rousseau's proto-Darwinian account of human evolution, but never tried to refute it. The article concludes by suggesting that Smith may have shared Rousseau's understanding of human nature to a greater extent than he wished to acknowledge, and that he may have hinted at this agreement through the traditional technique of esoteric writing.