This paper seeks to clarify Tocqueville's view that a political order premised on the primacy of individual reason over moral authority can be detrimental to genuine intellectual liberty. Beginning with Tocqueville's famous comment that Americans are Cartesians without having read Descartes, I compare Tocqueville's assessment of American intellectual life to Descartes' hopes for future political societies. I describe their disagreement about the effect that moral authority and rational individualism have on the development of the mind and locate its source in two competing theories of mind. This reveals a debate about our human needs with echoes in contemporary political discontent.