This chapter aims to clarify the nature of a shift in Feyerabend’s philosophical thinking in the 1970s, focusing on issues of realism, relativism, and pluralism. Against John Preston, who argues that FeyerabendFeyerabend, P. shifts from a realist position to a relativist position in publications after Against Method, I argue that realism-relativism is a misleading variable for characterizing Feyerabend’s shift. Rather, I characterize this shift as Feyerabend’s expansion of pluralism and suggest that this shift appears in Feyerabend’s publications starting in the late-1960s. Adopting the terminology of Matthew J. Brown and Ian James Kidd, Feyerabend’s shift is characterized by a move from arguments for pluralism within science to broader arguments for pluralism in society. I argue that this shift was largely due to: (1) Feyerabend’s rejection of an empiricist demarcation criterion for science in the mid-1960s, and (2) Feyerabend’s incorporation of John Stuart Mill’sMill, J.S. arguments for pluralism into his own publications starting in 1970. This shift can be characterized as a broadening or expansion of the scope of Feyerabend’s arguments for pluralism from contexts of scientific knowledge to the broader context of social or cultural (including ethical) knowledge.