Following my earlier rant on synthesising dualism, materialism and idealism, I came across this Searle paper linked from the Tucson 2006 “Towards a Science of Consciousness” conference programme. I’m guessing the paper is not new, but it’s undated.
Strangely I agree almost entirely with his own introductory words about the relationship between brain and consciousness – and if we were limiting ourselves to meat-based brains only – I’d completely subscribe to his “biological naturalism” tag myself – I simply chose to call it “physicalism” or “naturalism”. He says …
All of our mental phenomena are caused by lower level neuronal processes in the brain and are themselves realized in the brain as higher level, or system, features … biological naturalism.
At the same time I find his arguments against “property dualism” simply unnecessary. Again, the only problems are all the implied only’s and merely’s, and in this case because’s rather than if’s …. here Searle’s own summary of what at property dualist believes (and he doesn’t) …
(1) There are two mutually exclusive metaphysical categories that constitute all of empirical reality: they are physical phenomena and mental phenomena. Physical phenomena are essentially objective in the sense that they exist apart from any subjective experiences of humans or animals. Mental phenomena are subjective, in the sense that they exist only as experienced by human or animal agents.
(2) Because mental states are not reducible to neurobiological states, they are something distinct from and over and above neurobiological states. The irreducibility of the mental to the physical, of consciousness to neurobiology, is by itself sufficient proof of the distinctness of the mental, and proof that the mental is something over and above the neurobiological.
(3) Mental phenomena do not constitute separate objects or substances, but rather are features or properties of the composite entity, which is a human being or an animal. So any conscious animal, such as a human being, will have two sorts of properties, mental properties and physical properties.
(1) They are “mutually exclusive” because the nature of categories / classification / taxonomy / ontology is to deem things to be either distinctly in or out of any given category. But there is nothing to stop anyone better defining better catgories.
(2) “Because” seems to be question begging. This is true only if property dualism is literally true as described.
(3) Surely we all seem to agree there is not distinct mental and material “stuff” or substance. Stuff of any kind is pretty ethereal when you get down to fundamental nature / physics anyway, so that doesn’t help. Searle himself says ….
(This form of [bottom-up causation] …. is common in nature; for example, the higher level feature of solidity is causally explained by the behavior of the lower level elements, the molecules.)
And why stop at molecules ? The fact that we’re having any debate at all suggests we all agree that the mental and the material have some distinguishing features, properties (or aspects I would say). We also all seem to agree there exist some relationship(s) between these two things – whatever it is that distinguishes them and whatever it is they have in common. All we really need to debate is a useful working “basis for class membership” for being mental and not being mental, a definition of the mental “aspect” – and of course any useful subsets, and relevant overlapping sets based on other aspects, like physics and biology, etc.
It’ still a matter of levels and the quality of causal expalantion.