Cartesian Libertarianism: "Intrinsic Autonomy" and the need for Other-Worldly Substance

Contemporary discussions on freedom have recently drawn attention to the implications the mind-body relation.Contemporary discussions on freedom have recently drawn attention to the implications of the mind-body relation. Historically, the notion of freedom has centered on various naturalistic options, compatibilism, and weaker notions of libertarian freedom. This leaves strong agent causal libertarianism as a minority position. Entering these discussions, I seek to establish the relation between a particular mind-body view and strong agent causal libertarianism. I make two claims upon characterizing strong agent causal libertarianism. First, I argue that strong agent causal libertarianism requires some version of substance dualism (or immaterialist agency). Second, I argue that strong agent causal libertarianism probably requires something like classical or Cartesian substance dualism. Drawing from the philosopher John Foster in The Immaterial Self, I show that the central defining feature of the sort of libertarian agency under investigation is ‘intrinsic autonomy’. While I recognize that Cartesianism is unpopular in contemporary discussions, I agree with Foster that it is probably what is entailed if we are going to ground something like a strong agent causal libertarianism. The substance needed to explain this robust form of freedom begins to look like something not of this world and more like the substance described by René Descartes.