How does functionalism relate to physicalism? This isn’t a trivial question and this post is just to raise the issue rather than attempt to solve it. One of the things at stake is, if philosopher x is a functionalist and y an opponent, then if they have different definitions of what functionalism is, how they disagree will be less clear.
Ned Block and Jerry Fodor are broadly functionalists save for qualia and some higher cognitive functions (Fodor) while just assuming physicalism is probably true. So for instance, while the inverted spectrum argument is ofted wielded against physicalism, in the case of Block and Fodor, it targets only functionalism. And if functionalism in a strong sense is false but physicalism true, how are they different?
David Chalmers whose key interest is narrowly the ontology of mind, virtually interchanges the terms functionalism and physicalism. He argues the world is causally closed and that everything save conscious experience reduces to the physical. More specifically, he argues that the soft sciences are ultimately linked to the physical by their functionalizability. If something is functional, then it’s physical. How the micro world could specifically be understood on functional terms is unclear, but paragraphs like this are key:
“2. The principle of organizational invariance. This principle states that any two systems with the same fine-grained functional organization will have qualitatively identical experiences. If the causal patterns of neural organization were duplicated in silicon, for example, with a silicon chip for every neuron and the same patterns of interaction, then the same experiences would arise.”
So for him the “causal patterns of neural organization” is the same thing as the “fine-grained functional organization”. He notes later in the paragraph Searle’s disagreement, but where does Searl disagree when his own view champions “causal supervenience?” What is the difference between “causal supervenience” and “causal patterns of neural organization?” I think Searl believes if silicon or biology can truly duplicate physical causality in the right way, then consciousness results. But then, there is no equating for Searle causality with functionality. To sharpen my point here, consider Searle’s rejection of Penrose’s quantum account of mind. Searle affirms that the brian is 1) just a machine 2) a neural net. But isn’t that just what the functionalists have been trying to tell Searle all along?(!)
Not exactly, because the causal account of how that machine IS a machine matters. Modeling the synaptic connections perfectly is for Searle, still just a model. But isn’t Chalmers model going deeper than that? Herin lies where I think they’re talking past each other. At what point are we moving from a functional model to the real thing? When Chalmers says we’ll replace a neuron with a chip performing the same function, he seems to mean, down to the relevant level of physical causality wherever that is. And when Searle rejoinds, he seems to mean, a functional account can’t capture the relevant causal level. Chalmers assumes functionalism is physicalism, and Searle assumes it’s not.
Searle argues that functions are something we ascribe. Is there anything inherently “computational” about an abcabus (someone please tell me how to spell that word)? It’s a kids toy or a door prop as much as it is a calculator depending on how we interpret it. Whereas it would seem there is something more objectively real about physical causality. Now I don’t think that ultimately works because I think that physics is also a product of our interpretation. And more importantly, some of Searle’s more ambitious attempts to trivialize functions (that can be “anything”) have been adequately refuted.
Needles to say, I think Searle and Chalmers are both right in their deeper points. But the whole discussion is problematized by the lack of agreement on what functionalism actually is, and particular, how it relates to physicalism.