Nothing but a useful tool? (F)utility and the free-energy principle

Bruineberg and collaborators distinguish three philosophical positions about the status of Markov blankets in the context of active inference modelling, namely: literalism, realism, and instrumentalism. They criticize the first two positions and suggest that instrumentalism is "less problematic but also less interesting" (sect. 6.1.2, para. 5) Here, I sketch how literalists and realists might reply to Bruineberg et al.'s criticisms, and I explain why instrumentalism is more interesting and contentious than what Bruineberg and collaborators suggest.