From the outset, I should note that biological naturalism is emphatically not a form of materialism, given how Searle defines "materialism". According to Searle, materialism denies the existence of "inner, qualitative, subjective mental phenomena" and seeks to reduce mental states completely to "behavior, computational states, and so on" (Searle 1998, 47). Biological naturalism acknowledges the existence of subjective, conscious states and hence is not a form of materialism by Searle's definition. The question, then, is whether biological naturalism is a form of dualism.
According to biological naturalism, conscious states are "higher-level" features of the brain caused by the "lower-level" feature of neuronal activity:
Conscious states are entirely caused by lower level neurobiological processes in the brain. […] Conscious states are realized in the brain as features of the brain system, and thus exist on a level higher than that of neurons and synapses. Individual neurons are not conscious, but portions of the brain system composed of neurons are conscious. (Searle 2004, 113-14; cf. Searle 1998, 112-13)
Solidity is a property of macroscopic objects, not of molecules. No individual molecule is solid. However, when the molecules in an object are arranged in the right way, the object as a whole is solid. Similarly, no individual molecule is liquid, but when molecules interact in a group in the right way, the group as a whole is liquid: it flows, drips, etc. In both of these cases, the relationship between the "higher-level" feature (solidity, liquidity) and the "lower-level" feature (molecular structure) is clear and precise: in both cases, it is a matter of the activity of parts resulting in a certain behavior of the whole.
Thus, the analogy with liquidity and solidity seems to allow us to give biological naturalism at least some intuitive content: no individual neuron is a conscious being, but when neurons interact in the right way, the brain as a whole has conscious states—and the relationship between conscious states and neuronal activity is analogous to the relationship between (say) solidity and the molecular structure that causes solidity. But is the italicized part of this claim coherent?
Let us examine more closely the higher-level features that Searle cites as analogs of consciousness. They all seem to be behaviors or dispositions to behave in a certain way. In the case of solidity, the higher-level feature is the disposition to resist penetration. In the case of liquidity, the higher-level feature is the disposition to flow, drip, etc. In the case of digestion, the higher-level feature is the behavior of breaking down food.
Here Searle seems to miss an important disanalogy between conscious states and the other higher-level features which he cites as analogs of consciousness. Searle cannot say that conscious states are just behaviors or dispositions to behave in certain ways. That would be behaviorism, which Searle rejects. I do not deny that there might be some sense in which conscious states are “higher-level” features caused by neuronal activity; nonetheless, I fail to see how the relationship between conscious states and neuronal activity could be analogous to the relationship between solidity and the molecular structure that causes solidity.
In that case, the claim that biological naturalism is an alternative to dualism breaks down. As I have noted, the statement "Conscious states are higher-level features of the brain caused by neuronal activity", considered by itself, is not very precise. Even a property dualist could agree with it. A property dualist agrees that no individual neuron has conscious states, and she also agrees that the brain as a whole has conscious states as a result of its neuronal activity. Thus, she agrees with Searle that conscious states are, in a sense, higher-level features of the brain caused by neuronal activity. Yet she differs from Searle in regarding conscious states as “non-physical” properties. Now, when Searle claims that biological naturalism is an alternative to property dualism, he is clearly depending on our intuition that it would be wrong to call other higher-level features, such as solidity, "non-physical". In the absence of a clear analogy between consciousness and other higher-level features such a solidity, Searle loses that intuitive support.
I am not claiming that biological naturalism is really a form of property dualism. The problem is, rather, that I don’t have any clear idea what biological naturalism is. By themselves, the words "Conscious states are higher-level features of the brain caused by neuronal activity" simply fail to specify any precise model of the relationship between neuronal activity and conscious states. In his own mind, Searle may have a very clear model of the relationship between neuronal activity and conscious states. But when he tries to give his readers an intuitive grasp of that model, he uses analogies which, upon inspection, do not seem to hold up.
Am I missing something here, perhaps? Comments?
References:
Searle, John. 1998. Mind, Language and Society: Philosophy in the Real World. NY: Basic Books.
Searle, John. 2004. Mind: A Brief Introduction. Oxford: Oxford UP.
You might consider looking at the work of J.P. Moreland. He has written several pieces attacking Searle's work, specifically on how Searle thinks of himself as offering an alternative to dualism.
ReplyDeleteword on the street is that in private conversation (with DWS) Searle basically hates the title "property dualist" but will admit that he is some sort of "property pluralist" (because properties of culture, or "society") are higher level in the same way that CS properties are higher level in relation to physical properties, etc. but yes, good analysis and I largely agree. I also don't understand why Searle disagrees with David Chalmers version of functionalism, which basically has the same sort of property dualist set up.
ReplyDeleteYeah, I've heard Searle say basically the same thing. The basic idea is reasonable enough: Sure, consciousness is a different kind of property than neuronal activity. But then again, EVERY brain property is a different kind of property than every other brain property (e.g. grayness is different from wetness). So it makes no sense to divide all brain properties into two camps, the mental and the non-mental. Instead of talking about property dualism, we should be talking about property pluralism.
ReplyDeleteI don't know enough about Chalmers's views to comment intelligently on them. If we're talking other philosophers, one thing that I don't understand is why Searle rejects Jaegwon Kim's theory that mental causation is a large-scale causation grounded in small-scale (i.e. neuronal) causes. It seems like exactly the same thing as Searle's view. As far as I can tell, Searle rejects Kim's view because Kim categorizes it as a form of epiphenomenalism, and Searle doesn't think of his own view as a form of epiphenomenalism.
What I think about Joseph's charge against Searle's BN that it does not give a precise idea about the relationship between mind and brain is that it misses the point that Searle wanted to say. The reason is that BN, according to Searle, is a solution to the philosophical problem of consciousness and therefore it cannot be considered as a solution to the empirical/scientific problem of consciousness.The latter one according to Searle is a 'problem in neurobiology' that how actually conscious states are realized in the brain structure.Thus considering BN as a conceptual/formal solution to the problem , we can say that it is intuitively sufficient. But as Joseph said rightly, what sort of ontological commitment that BN has got given the contemporary ontological debates in the philosophy of mind is little bit unclear. Yet whatever I have understood from Searle's writings is that a sort of 'grand monistic' grounding is evident rather than the 'property pluralism' as a peculiari said.
ReplyDeleteThanks for the comment, Robo.
ReplyDeleteYou're right when you say that Searle intends BN only as a conceptual/formal model of the mind-brain relationship, rather than as a precise neurobiological mechanism.
However, I disagree with you when you say that BN is "intuitively sufficient". Personally, I'm not even sure what Searle means when he describes BN. He says that mental states are higher-level features caused by lower-level neural activity. I can understand what "higher-level features" means in the case of liquidity, solidity, etc.: in those cases, the higher-level feature is simply a behavioral disposition. But Searle doesn't mean that mental states are behavioral dispositions, because he isn't a behaviorist. So, when Searle calls mental states "higher-level features" of the brain, I just don't know what that means. And since I don't know what it means, I can't tell whether it's really an alternative to property dualism.
Maybe it's just a lack of imagination on my part, of course!
I think at the end of the day Searle needs to bite the bullet and admit that he's doing ontology. He won't want to because of all the negative connotations he perceives emanating from that word, but in reality he is developing an ontology of properties and their relations. He can remain a monist or naturalist or whatever he wants to title himself, but when he talks about solidity being a property of matter and digestion being a biological property (just like consciousness) he isn't claiming that these are properties of a different substance. But he is saying that there are different kinds of properties with various dependence relations holding between them. As he himself says, consciousness is not reducible, so positing dependence relations does not mean reduction.
ReplyDelete