What I object to is the unthinking move from linguistic premises to ontological conclusions, from the assumption, for instance, that if you have an ‘ineliminable’ predicate that features in an explanation of some phenomenon of interest, the predicate must name a property shared by everything to which it applies. (A predicate is ineliminable if it cannot be analyzed, paraphrased, or translated into less vexed predicates.)
Philosophers speak of ‘the pain predicate’. When you look at creatures plausibly regarded as being in pain, you do not see a single physical property they all share (and in virtue of which it would be true to say that they are in pain). Instead of thinking that the predicate, ‘is in pain’, designates a family of similar properties, philosophers (including Putnam in one of his moods) conclude that the predicate must name a ‘higher-level’ property possessed by a creature by virtue of that creature’s ‘lower-level’ physical properties. You have many different kinds of physical property supporting a single nonphysical property. This is the kind of ‘non-reductive physicalism’ you have in functionalism.
Non-reductive physicalism has become a default view, a heavyweight champ that retains its status until decisively defeated. Non-reductive physicalism acquired the crown, however, not by merit, but by a kind of linguistic subterfuge. If you read early anti-reductionist tracts – for instance, Jerry Fodor’s ‘Special Sciences (Or: The Disunity of Science as a Working Hypothesis)’ (Synthese, 1974) – you will see that the arguments concern predicates, categories, taxonomies. Fodor’s point, a correct one in my judgment, is that there is no prospect of replacing taxonomies in the special sciences with one drawn from physics. But from this no ontological conclusions follow – unless you assume that every ‘irreducible’ predicate names a property.
This language-driven way of thinking is not one that would have occurred to the ancients, the medievals, or the early moderns – or to my aforementioned philosophical models. It is an invention of the 20th century, one that has led to the emasculation of serious ontology.
~From an interview with Richard Marshall at 3am.