“…There has been a promising uptick in explicit defenses of the Basic Argument over the last decade (cf. Coates 2017, Hartman 2018, Hendrickson 2007, Istvan 2011, Klemick 2013 (i) it must not stop the regress in an ad hoc or otherwise arbitrary way (e.g., by insisting, without argument, that the regress in unproblematic or uninteresting 46 ), and (ii) it must not answer the regress in a way that gives rise to another vicious regress, where this new regress stopped in an ad hoc or arbitrary way (e.g., by insisting, without argument, that the new regress in not problematic and/or is not sufficiently interesting to warrant a reply 47 ). So, even if the unstoppable regress challenge does not decisively establish the impossibility of free will or moral responsibility, it gives us a distinct metric by which to measure the "cost" of possibilism-friendly accounts of free will.…”