 This entry’s approach to defining neoliberalism differs from that of Biebricher, Slobodian, Whyte, and Brown (Brown 2019) in much the same way as political theorists and philosophers differ from historians, and indeed how philosophers differ from political theorists. Neoliberalism can be understood as a somewhat static doctrine to provide a basis for evaluation, and that can later serve to explicate variations on the view. It is perhaps more natural to treat neoliberalism as a dynamic system of ideas, as historians do, and even some political theorists. Nonetheless, a review of Hayek, Friedman, and Buchanan reveals a sufficiently static doctrine to count as a kind of political philosophy.