Monday, August 28, 2006

On substance dualism, in answer to that question about beer, from Scott Brisbane

1. Problem of Interaction
The argument that we do not understand how a soul interacts with a physical body, appears to be based on an appeal to our ignorance (argumentum ad ignorantiam). For it assumes if we do not know “how” A causes B, especially if the two consist of different properties, that it is not reasonable to believe the two can interact. Yet, as Craig and Moreland point out, a tack can be moved by a magnetic field, and gravity acts on a planet millions of miles away.26 Gravitational forces and magnetic fields appear to have very different properties to the solid and spatially located entities they affect, and although we may not understand “how” such interaction takes place, it nonetheless does—just as we are alert to causation between the mind and body. As another example, even if one is not a theist, most do not view it as inconceivable to believe that God (given God’s existence) created the material universe and could act within despite each one being very different.
A second defense is that the question of “how” the mind interacts with the body may not even arise. As Craig and Moreland explain in depth:

One can ask how turning the key starts a car because there is an intermediate electrical system between the key and the car’s running engine that is the means by which turning the key causes the engine to start. The “how” question is a request to describe that intermediate mechanism. But the interaction between mind and body may, and most likely is, direct and immediate.27
If the interaction is direct and immediate, as Thomists would tend to believe, then there is no reason to assume there is an intermediate mechanism that facilitates the interaction.


Anonymous said...

I can't believe you took the time to address that question, Dr Reppert. I deliberately ignored it when I first saw it posted. I didn't think it worthy of response.

Victor Reppert said...

Well, the objection is just an instance of what Bill Vallicella calls the "traditional problem of interaction." "If dualism is true, how does the mind interact with the body?" This is supposed to put dualism in the tank right away so that we can start discussing the fate of folk psychology given the fact that we all know (don't we???) that OF COURSE physicalism is true. Absent any further development of the argument, I think William Hasker is right: "this argument may well hold the record for overrated objections to philosophical positions.:" Over at Maverick Vallicella seems to be treating the "pairing problem" as a distinct argument, whereas in my book I see the "pairing problem" as a sophisticated attempt to develop the idea behind the traditional problem of interaction. But to merely ask the question Hivemaker asks without any further development of the argument or even awareness of how it has been answered by dualists of various stripes is to advance a highly overrated argument. But he isn't the only person arguing this way.

HiveMaker said...

I'm glad that you appreciate that there is an issue here, yet I'm afraid you've misinterpreted the scope of the question.

When I ask, "why does beer work?", I am not asking for a Deep Ontologico-metaphysical Grounding of the Nature of Causality, I am asking for an everyday characterization of the phenomenon. When I stick my key in the cigarette lighter, the car does not go. When I gouge the paint with my key, the car does not go. But when I turn the key in the ignition, the car does go.

Do you see?

When I want to understand how something works, I ask "why does turning the key work?" and I expect an explanation about tumblers and ignitions. But you've simply "gone up in a balloon" on the issue, and said "well, gollee, why does anything cause anything? causality is direct and immediate."

All I'm asking for is a simple characterization of the phenomenon. I can explain, in ordinary language, how an ignition system works, without going up in a balloon or demanding that I give an account of the Metaphysical Truth of Causality.

So, why does beer work? Really, my question is much more humble than you seem to think it is. Why is it that rubbing beer on my skin does not make me intoxicated, whereas injesting it does? You say that consciousness is nonmaterial? Fine, just explain to me what its relation ship is, in practical, operational terms, to the nervous system. I'm not demanding a metaphysical "account of how one substance can affect another", I'm only asking for what we are able to say about this alleged extra substance in virtue of the way it interacts with the world.

Just tell me, "conscious ectoplasm is (or is not) susceptible to physical manipulation under the conditions X, Y, and Z"; "consciousness, to interact with the physical world, seems to require a bio-vessel with such-and-such a neurological structure, and when certain parts of the structure are damaged, consciousness loses its ability to interact with physical reality in such-and-such capacity."

Why does beer work?

Victor Reppert said...

Nonphysical states are not fully describable in terms of physical laws. But they are integrated with physical systems. The laws governing those "nonphysical" states work in close harmony with physical ones to produce normal effects. There is enough freedom from the nexus of nonrational physical causation so that reasons-explanations can be basic explanations and need not be cashed out in nonrational terms. Otherwise, as I see it, the entire enterprise of science would not be possible. And I don't believe that physical states determine all other states, because I do believe in a libertarian view on free will which, on my view, alone makes the whole business of attributing responsibility to actions possible.

Here William Hasker's The Emergent Self (Cornell 1999) is just plain required reading.

Anonymous said...

HiveMaker, it doesn't appear that you actually read Victor's post, since the point of it was that there is in fact no issue here. Re-read the first sentence.

Anonymous said...

How does one distinguish between libertarian free will and random action?
If one has no determining reason for his acts, how can he be held responsible for them?

Don Jr. said...


Self-determinism and indeterminisn are, I think, usually recognized as two different forms of libertarian free will. I'm not entirely certain on that though. If I'm correct, indeterminism would result in the dilemma you bring up but self-determinism, as I understand it, eludes it.

In my experience with discussions about free will, people often use various terms differently and various terms to mean the same thing. So some people mean indeterminism when they say libertarian free will while others mean self-determinism. Also, agent causation is, I think, a term used for self-determinism. But it is the idea behind the terminology, not the terminology itself, that matters.

HiveMaker said...

That reply is much closer to what I'm looking for; genuine conversational progress has occurred.

Now, one very simple and straighforward answer to the question, "why does beer work", the kind of answer I would give and the kind of answer you expect your children to come home from school knowing, would look something like this:

"Ethanol is quickly absorbed into the bloodstream and reaches the brain. As a small molecule, it is able to cross the blood-brain barrier. For reasons that are still being studied, it then triggers the release of dopamine and endorphins into the bloodstream, which cause euphoria.

The CNS (Central Nervous System) depressant effect likely is due to ethanol's acting on the BK channels. [1] A BK channel is a calcium dependent potassium channel. Ethanol potentiates the activity of BK channels, which reduces the excitability of the neuron. [2] It has been known to act on GABA receptors, but this is probably just a secondary effect from activation of the BK channels. Its effect on GABA receptors can cause Anterograde amnesia, similar to benzodiazepines such as diazepam. [3] GABA is an inhibitory neurotransmitter, meaning it acts to slow down or inhibit nerve impulses. Ethanol increases the effectiveness of GABA acting through GABAA receptors. When used over a long time, ethanol changes the number and type of GABA receptors, and this is thought to be the cause of the violent withdrawal effects of alcoholics.

Ethanol also interferes with synaptic firing and thus, disrupts brain functions [4], which is why one of the effects of hangover is lowered intellectual capacity. The effect is caused by an increased concentration of intracellular calcium, which overstimulates neurons and causes them to lose their end segments (which are responsible for I/O operations in neurons). The effect, however, is temporary [5]. Alcohol does not kill brain cells when drunk [6],[7] because at the concentrations which are typically reached when alcoholic drinks are consumed (~0.1%) it is incapable of permanently harming neurons. At higher concentrations (~50%), ethanol is highly toxic to most living organisms (which is why it can be used as a disinfectant). However, loss of consciousness and death would result long before these concentrations are reached in the brain.

Alcohol provokes release of dopamine in limbic system. [8] [9]

Dopamine activity is responsible for pleasant feelings related with alcohol, motivation to continue this activity and also influences secretion of prolactine (Piotr Skalba, "Endokrynologia ginekologiczna", ISBN 83-200-2163-4, page 54), inhibiting its production , and secretion. (see Prolactin for more details) increased synaptic Dopamine is broken down by monoamine oxydase enzyme to Norepinephrine, which may cause agitation, anxiety and fear (see Norepinephrine#Role_in_attention, though article is lacking effects on nervous system itself.)

Dopamine and norepinephrine interplay is responsible for inducing psychological effect of Frustration, and Mania . Drop of Prolactin levels might be responsible with antisocial behaviour in chronic alcoholics."

All very unballoonish and nonmetaphysical so far. Is there any theist, non-naturalist, or otherwise who believes that any of the above is false?

Of course, there are ways and then there are ways of being a non-naturalist. The post title is about substance dualism, but Victor Reppert's reply is compatible with non-substance-dualisms, especially emergent property dualisms. (Of course, I don't have a grip on the details of his specific theory; but then, that's why I'm asking. Quite why this should generate so many comments along the lines of "I can't believe you deigned to respond" and "I don't understand how explaining what the brain can and cannot do is relevant to whether theories that claim to explain what the brain can and cannot do are correct" is opaque to me.)

I myself am a hair's breadth away from being persuaded that some form of Wittgenstinian semantic non-naturalism is true -- that semantic predicates are not subject to synthetic reduction to natural predicates. But this ends up being a truth about the limits of language, not a truth about biology or complexity or ontology. So I'm no dogmatist or ideologue on this issue, and I wouldn't consider it a blow to my ideological identity if I had to affirm that this or that thesis of Naturalism is false. I'm very close to 100% agreement that "reasons-explanations can be basic explanations and need not be cashed out in nonrational terms". Indeed, if the nonnaturalism I'm tilting towards is correct, the thesis would be even stronger: reasons-explanations not only need not, but could not in principle be cashed out in nonrational terms.

But importantly, the question "why does beer work" doesn't really directly touch on reasons-explanations. Let's grant, for argument's sake, that either substance or property dualism is true, that mental substances/properties emerge in Hasker's sense, and that "they are integrated with physical systems. The laws governing those "nonphysical" states work in close harmony with physical ones to produce normal effects. There is enough freedom from the nexus of nonrational physical causation so that reasons-explanations can be basic explanations and need not be cashed out in nonrational terms."

Good, we've sent our philosophy balloons soaring away. Now back to questions of what is already known by observation to be true. Assuming no one challenges any of the facts about the metabolization of ethanol I supplied above, what can we say about the properties of this "causal nexus" given that alcohol works when present in the brain, but not when it is present only in, say, the skin ?

I'm going to go out on limb here, and predict that everyone will agree that "whatever this extra substance is, it seems as though its causal nexus with the rest of the world is spatially linked to specific portions of the brain." None of this really even touches philosophy yet, but I'm trying to motivate a basic set of concepts based on shared agreements about what the data actually shows. Since I seem to write in a way that lends itself to being misunderstood, maybe this will spur further conversational progress.

Anonymous said...


Your simple, no-nonsense explanation of how beer works is only possible because a whole lot of philosophically contentious terms and concepts are taken for granted, including (and not limited to): ethanol, absorbed, reached, triggered, acting, interferes, disrupts, intellectual capacity, reasons, etc. Just because scientists have the luxury (or perhaps the need) of using a very meat-and-potatoes approach to language and terminology doesn't mean that a 'scientific' explanation is automatically unambiguous and free of metaphysical baggage. If you can't see that that's your problem.

HiveMaker said...

You forgot to tell me whether anything said was false.

Or are "true" and "false" merely "metaphysical constructs" imposed by the hetero-normative phal-logocentric patriarchal colonialists that enlightened post-modern apologetics have done away with?