Zoe Drayson

The computational properties of a system are generally thought to be independent in some sense from its physical properties, in virtue of the fact that computation is a formally characterized concept. Several philosophers have recently challenged the idea that such “medium‐independence” is an essential feature of computation by arguing that some kinds of computation lack medium‐independence. This paper explores and rejects three such arguments in an attempt to defend the essential medium‐independence of computation.

Clark (_Philosophical Psychology_ 19(3):291–307, 2006) proposes that a standard challenge to the hypothesis of extended cognition can be avoided in the case of linguistically structured cognition, because the role played by our public manipulation of linguistic artifacts is irreducible to the role played by the brain’s operations over internal representations. I demonstrate that Clark’s argument relies on a view of the brain’s cognitive architecture to which he no longer subscribes. I argue that on Clark’s later view of the brain as engaged in ‘predictive processing’, his earlier defense of extended cognition from this challenge is no longer an effective strategy. I explore the implications of this for Clark’s attempts to reconcile his previous arguments for extended cognition with his characterization of the predictive-processing brain.

Daniel Dennett's distinction between personal and subpersonal explanations was fundamental in establishing the philosophical foundations of cognitive science. Since it was first introduced in 1969, the personal/subpersonal distinction has been adapted to fit different approaches to the mind. In one example of this, the ‘Pittsburgh school’ of philosophers attempted to map Dennett's distinction onto their own distinction between the ‘space of reasons’ and the ‘space of causes’. A second example can be found in much contemporary philosophy of psychology, where Dennett's distinction has been presumed to be equivalent to Stephen Stich's distinction between doxastic and subdoxastic states. Both these interpretations of the personal/subpersonal distinction, and also Dennett's own philosophical views of the mind, go beyond the personal/subpersonal distinction itself. They each involve supplementing the distinction between personal and subpersonal explanations with metaphysical claims about the relationship between the two kinds of explanation and the entities they posit.