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WillowOne's Positions

Dualism

My Positions

  1. I reject dualism in every form I have met: the claim that reality contains two fundamentally different kinds of thing, the physical and the mental, neither reducible to the other.
  2. The mind depends on the brain: mental states are emergent properties of complex physical systems, conscious experience corresponds to and changes with brain states, and in every case we know of the substrate is a brain, so there is no such thing as a disembodied mind. (That the substrate must be physical does not mean it must be biological; see Substrate Independence.)
  3. Substance dualism, the view of René Descartes that the mind is an immaterial thing which could in principle exist without a body, is the version the religions need and the one with the worst problems. The arguments against it are set out in the notes below and under Souls; this note also places it among its relatives.
  4. Property dualism, which keeps one kind of substance and gives it two kinds of property, is harder to refute and, I think, not worth refuting. If the mental properties are fully fixed by the physical ones and make no difference the physical ones do not already make, the claim that they are "a different kind" of property has no consequences, and I set it aside under Popper's Razor. This is one of the views I hold loosely (World View).
  5. Epiphenomenalism, the version on which the mental is real but does nothing, is the one dualism that survives the physics, and it survives by making itself unbelievable: on its own account, no belief in it was ever caused by the thing it is about. It has its own note.

Notes

  1. The family. Dualisms differ on what the two things are and on how they are related. Substance dualism: two kinds of thing, mind and matter. Property dualism: one kind of thing with two irreducible kinds of property, the physical and the phenomenal; David Chalmers' "naturalistic dualism" is the best-known current form. On the relation: interactionism (each acts on the other; Descartes); epiphenomenalism (matter acts on mind, mind does nothing back; Thomas Henry Huxley compared consciousness to the steam-whistle on a locomotive, which accompanies the work and contributes nothing to it); parallelism (neither acts on the other and God keeps them in step from the start; Gottfried Wilhelm Leibniz's pre-established harmony); and occasionalism (God does the causing on each occasion). The last two are historical curiosities that show how far one has to go to keep two substances and the appearance of one world.
  2. The interaction problem, which is the whole problem. If the mental is to make a difference to the physical, it must change what some physical system does. Physics is causally closed as far as anyone has ever been able to check: every change in the position or momentum of anything has a sufficient physical cause, and the conservation laws hold in neurons as in billiard balls. An interactionist needs a place in the brain where the physics does not add up, and must either produce it or explain why four centuries of looking have missed it. Descartes nominated the pineal gland. It secretes melatonin. A non-physical mind would either violate the conservation of energy or be causally inert, in which case it could not be the thing that is reading this.
  3. The evidence from damage. Brain injury, stroke and dementia alter personality, memory, perception and moral judgement in specific and predictable ways depending on the region affected (Phineas Gage being the classic case). If the mind were separate from the brain, damage to the brain should affect the mind's expression but not its content. It affects both.
  4. The evidence from chemistry. Anaesthetics switch consciousness off. Psychedelics, antidepressants and alcohol alter its character. There is no dualist account of why molecules should have these effects on something immaterial.
  5. Epiphenomenalism's self-inflicted wound. Suppose, to escape the interaction problem, that the mental does nothing. Then my saying "I am in pain" is caused entirely by brain states, and the pain itself, the mental item, had no hand in it. The same goes for every utterance of the word "consciousness", every book about qualia, and the belief in epiphenomenalism. On this view the whole philosophy of mind would have been written exactly as it was if there had been no experience at all. I take this as a reductio, as Frank Jackson eventually did. Worse, it severs the one tie that gives us any evidence for other minds: if experience causes nothing, nobody's behaviour is evidence of theirs.
  6. The pairing problem. Jaegwon Kim asked the substance dualist a simple question. Two immaterial minds and two brains: what makes this mind the one attached to this brain? Physical causes are paired with their effects by spatial relations, and a non-spatial substance has none. Nothing in the theory says why my mind is hooked to my body and not to yours, and the only answer on offer is that God arranged it, which is the theory confessing it has none.
  7. Why it is so natural. Children are dualists before anyone tells them to be (Souls note 5): the brain models the self as something that has a body, and dualism is that model read back as an inventory of the world. Grammar reinforces it; "I have a brain" has the same shape as "I have a hat". And the first-person and third-person views of the same event are so different in character that it seems obvious they must be views of two things. They are views of one thing from two positions, as the inside and the outside of a house are, and the inside of a house is not a second building. Gilbert Ryle called the Cartesian picture "the ghost in the machine" and diagnosed it as a category mistake: treating the mind as a further thing alongside the body, as a visitor might ask to see the university after being shown the colleges.
  8. Where the self-model came from. Early life probably reacted to stimuli without experiencing or thinking about them. Later, organisms developed systems that modelled their own states in order to regulate their reactions, and the operation of those systems, felt from the inside, is consciousness. On this view consciousness is what certain kinds of information processing feel like from the inside, and it was selected for because an organism that models its own states can regulate them better. The self-model is also the source of the dualist intuition in note 7: a model of "the one who has this body" is easily mistaken for a report of a second thing.
  9. Property dualism, set aside. Chalmers' version is careful. The physical facts fix every functional fact about the brain; the phenomenal facts are fixed by them in turn through "psychophysical laws"; but the two are not identical. I cannot refute this, because it has been built so that nothing could. If there were such laws they would be invisible to every experiment, since every experiment measures functional facts and those are agreed to be physical. A view that agrees with physicalism about every observation and differs about the label is a view I do not need an opinion on. I note that Chalmers, following his own argument, has become sympathetic to Panpsychism and to Russellian monism, which is where property dualism goes when it tries to say what the extra properties are properties of.
  10. The thought experiments. The cases usually offered in support of dualism (Mary's Room, Philosophical Zombies) establish at most that we cannot currently imagine how experience arises from matter. An argument from what we can imagine is an argument from Personal Incredulity. See my notes on Mary's Room for why I do not think Mary learns anything about the world.
  11. What dualism was for. It is the metaphysics of the soul, and its persistence has less to do with the arguments than with what rides on it: survival of death, judgement, reincarnation and a self that could in principle be elsewhere (Life After Death, Reincarnation and Karma). The apologetic Argument from Consciousness is dualism being used as a premise. My atheism does not depend on rejecting dualism, but the religions depend on accepting it, and that asymmetry is worth noticing.
  12. What I keep. The dualist is right that a complete third-person description does not eliminate the first-person view, and right that this is puzzling. I take the puzzle to be about concepts and explanation (Hard problem of consciousness), not about what exists, and I take four centuries of causal closure to be the better evidence.

Personal Context

  1. I am an atheist. Dualism is a load-bearing assumption of most religions, since without a soul there is nothing to be judged, saved or reincarnated, and so the failure of dualism bears on those claims too (see Life After Death).

Sources

  • Descartes, R., Meditations on First Philosophy (1641), Sixth Meditation; The Passions of the Soul (1649), articles 31–34, on the pineal gland
  • Huxley, T. H., "On the Hypothesis that Animals are Automata, and its History", Fortnightly Review (1874)
  • Jackson, F., "Epiphenomenal Qualia", Philosophical Quarterly 32 (1982); "Mind and Illusion", in A. O'Hear (ed.), Minds and Persons (2003), for the recantation
  • Kim, J., "Lonely Souls: Causality and Substance Dualism", in K. Corcoran (ed.), Soul, Body, and Survival (2001)
  • Ryle, G., The Concept of Mind (1949), chapter 1
  • Chalmers, D., The Conscious Mind (1996)
  • Dennett, D. C., Consciousness Explained (1991)
  • Robinson, H., "Dualism", Stanford Encyclopedia of Philosophy — https://plato.stanford.edu/entries/dualism/

Also see