The final chapter of RECS tackles the metaphysical implications of the radical stance. Gibson was a staunch realist, but there are some odd elements to entities like affordances that, to certain minds, sound like idealism or antirealism of some kind. Realism is, essentially, the claim that there is a world independent of our experience of it, and that we can have basically accurate knowledge of that external world. In modern times this reality has been equated with the description given by physics. Affordances don't belong to physics, however; whether relations or dispositions, they are, at heart, facts which span the organism and the environment. This sounds wrong to a lot of ears (as Ken's comments on that post readily show!). Chemero therefore devotes the final chapter to defending the claim that RECS can be realist; this matters, because people tend not to like idealism in their science these days, and it's going to be a standard philosophical objection to the RECS programme if not addressed.
Heartbreak among the roses
3 hours ago