This article reconsiders the work of Raymond Aron in order to explore the fracture lines that existed between conservative forms of political liberalism, as advocated by Aron, and neoliberal ideas of economic or market freedom associated with Hayek and his followers. These tensions between Aron and Hayek are analysed by assessing Aron’s involvement in the Mont Pèlerin Society and the Congress for Cultural Freedom through the 1950s, and then considering the arguments of his 1962 review of Hayek’s Constitution of Liberty (...) and his 1963 Jefferson Lectures. While Aron has been largely neglected in the existing literature on neoliberalism, it will be argued that he was the key sociological figure to engage critically with neoliberalism in its formative years and, beyond this, that the value of his work today lies in its defence of the social basis of democracy and freedom against the raw economism of neoliberal thought. (shrink)