Theory Reduction by Means of Functional Sub‐types

Abstract

The paper sets out a new strategy for theory reduction by means of functional sub-types. This strategy is intended to get around the multiple realization objection. We use Kim's argument for token identity (ontological reductionism) based on the causal exclusion problem as starting point. We then extend ontological reductionism to epistemological reductionism (theory reduction). We show how one can distinguish within any functional type between functional sub-types. Each of these sub-types is coextensive with one type of realizer. By this means, a conservative theory reduction is in principle possible despite multiple realization. We link this account with Nagelian reduction, as well as Kim's functional reduction.

The “Multirealization” of Multiple Realizability

“…Family concepts (5) will generally allow for domain-specific sub-types (4) on the basis of shared properties (1,2). Recently, Lewis' idea of domain-specificity was revived by Esfeld and Sachse (2007) in terms of "functional subtypes", i.e. a combination of (3) and (4) without, however, further analyzing (3) in terms of (1) or (2).…”

On the Distinction Between Cause-Cause Exclusion and Cause-Supervenience Exclusion

“…In other words, (P1)′, (P2)′, (P3)′ Id , and (P4)′ can all be true. 5 For instance, in the context of biological causation, Esfeld and Sachse (2007) appear to interpret an analogous argument against the non-identity premises to establish the claim that all higher-level events are identical to physical events. The authors use the 'causal exclusion problem' (2) to establish the claim that 'All there is in the world are entities that are identical with fundamental physical tokens and their configurations' (2), where the term 'tokens' is intended the same way as we use the term 'events'.…”

“…By highlighting the difference between (P3)′ and (P3)′ Id it becomes clear that the universal 'token identity thesis' should be carefully distinguished from the negation of (P3)′. 6 For instance, if it should actually turn out true that all mental and other higher-level types are identical to physical types as some authors have claimed (Esfeld and Sachse 2007;Kim 1998;Lewis 1966) then it is undubitably true that all mental events are physical events. The interesting point about this conclusion is, of course, that the argument for the negation of (P3)′ Id consisting of some modified or supplemented (P1)′, (P2)′ and (P4)′ is superfluous once an independent argument for type identity has been established, because any universal type identity claim will imply the negation of (P3)′ Id .…”

Replacing Functional Reduction with Mechanistic Explanation

“…3. Esfeld and Sachse (2007) have argued that by introducing functional sub-types we can have property identities and conservative functional reductions, multiple realizability notwithstanding. 4.…”