Criticisms of dualism: is substance dualism tenable?
Thomas (Janice L.)
Source: Thomas (Janice L.) - Mind and Person in the Philosophy of Religion
Paper - Abstract

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  1. Essential reading – 39
  2. Further reading – 39
  3. Introduction – 39
  4. What is immaterial substance? – 40
  5. Genuine entities are countable – 41
  6. Evolutionary1 considerations – 42
  7. Interaction between the immaterial and the physical – 43
  8. Learning outcomes – 44
  9. Sample questions – 44
  10. Tips on answering the sample questions – 44
Full Text
  1. Essential Reading
  2. Further reading
  3. Introduction
    • As the Introduction to the last chapter notes, a theory is not disproved by showing that arguments in its favour are flawed, unless every imaginable support for the theory is equally undermined (and even then at any time a supporter of the theory could come forward who has imagined a totally novel defence). Dualism is not proven to be wrong by showing that the major arguments which have been given in its defence so far are all vulnerable.
    • We turn now, however, to criticisms of dualism which have been directed at the very notion that reality consists of two, utterly metaphysically distinct, kinds of substance — one physical or material and the other spiritual or immaterial. These four criticisms aim to show that substance dualism is untenable. When they have been looked at in detail, we will then turn to consider substance dualism's major rival — materialism2.
    • The four criticisms are:
      … the mysteriousness of immaterial substance
      … genuine entities are countable and immaterial substances are not
      … an argument from evolutionary3 considerations
      … the difficulty of explaining how an immaterial mind and an exclusively physical body could interact.
  4. What is immaterial substance?
    • Reading
      "Churchland (Paul) - Matter & Consciousness", 1984, pp. 18-19.
      "McGinn (Colin) - The Character of Mind - An Introduction to the Philosophy of Mind", 1982, pp. 23ff.
      "Smith (Peter) & Jones (O.R.) - The Philosophy of Mind - An Introduction", 1986, pp. 45-46.
    • When McGinn says, ‘it is quite unclear that there is any intelligible conception associated with the words "immaterial substance", he is expressing in a brief, pithy form a sentiment which many critics feel. Immaterial substance feels like a very mysterious thing indeed. We do not know anything positive about it. We know from its supporters only what it is not. We know that it does not have a physical location or any other spatial properties, and that it cannot suffer any sort of corruption or decay. The laws of physics have no application to it nor do any of the principles of chemistry, biology or any of the other natural sciences. If it is governed by its own laws, we have no idea what they are.
      But is there really something (could there be something) of which all these negatives are true? Is immaterial substance not a contradiction in terms? When we describe something as ‘immaterial' or ‘non-material', surely we mean to say, among other things, that it is not substantial.
    • In any event, trying to give an account of the nature of mind by positing an immaterial substance to furnish the locus of mental phenomena and be the thing that has mental states is like referring to the 'dormative power' of a sedative in order to explain its capacity to put people to sleep. To say that I can reason and use language, have feelings and, indeed, all my experiences in virtue of having somehow ‘in' me (or connected with me) an immaterial substance explains nothing.
    • In contrast, as Churchland says, modern neuroscience already has impressive explanatory resources. It can tell us much about the internal constitution and the constitutive elements of the brain, and the laws governing their behaviour. It can then draw connections between brain constitution, activities and defects and bodily behaviour, and it can explain human capacities and pathologies in terms of those brain structures and defects. In studying such things as depression, motivation, attention, vision and sleep, neurologists and neuropharmacologists (nerve specialists and brain chemists) have discovered numerous interesting facts about the neurochemical and neurodynamic basis of sensation, perception and consciousness.
    • Meanwhile, the science of artificial intelligence4 has learned a great deal about the nature of certain sorts of reasoning and has perfected machines which can make complex and sophisticated deductions, mathematical calculations — and make them far faster than any human reasoner. The claim that only an immaterial mind can reason would seem to have been disproved in the computer workshop.
    • Of course, there are still a great many mysteries about the nature of mind, but the physical sciences can rightly claim to have had enormous success. And it seems clear that they have had that success because they start from the assumption that the various functions and capacities of the mind and mental states are dependent for their character and qualities on the nature and detailed character of the working of the various parts of the brain and central nervous system.
    • There are many scientists who insist that once you know all about the brain in the minutest detail, you will also know all there is to know about mind and mental states because the latter are nothing over and above the brain (and central nervous system) and its states. But it must be said that the dualist is making no logical mistake in continuing to deny the identity of mind and brain, mental states and brain states. The dualist can insist in reply that immaterial substance is real and necessary — if not, so far as science has revealed, to the nature and functioning of mental life, then perhaps to account for the persistence of individual minds over time, particularly beyond death.
    • The opponent of dualism is likely to respond to this last point by maintaining that immaterial substance as a principle of identity is another mystery whose demystification we are entitled to continue to demand from the dualist. In Part II of this guide, we will look in detail at the traditional puzzles and problems that arise when you try to account for — what almost everyone agrees seems to be true — the fact that persons persist over time.
  5. Genuine entities are countable
    • Reading
      "Smith (Peter) & Jones (O.R.) - The Philosophy of Mind - An Introduction", 1986, pp. 46-49.
      Also, if you can, read:
      "Strawson (Peter) - Self, Mind and Body", which rejects Cartesian dualism as incoherent and accepts some form of materialism5 as the only viable alternative.
    • If you are asked to count how many persons or minds there are in the room at the moment you should have little difficulty carrying out the request (unless you are in a packed sports hall or crowded cathedral at the time!). You will know exactly what to do: you will count all the human beings. Even if twins6 joined from birth are present there should be little problem, so clear are we about how much of what goes on is one human body.
    • But what if the substance dualist is right that the mind is a quite distinct entity from its body? How can anybody — even a staunch believer in dualism — count persons in the sense of ‘immaterial substances'? We might think, commonsensically, that there is one and only one for every living human body. But nothing in the definition of immaterial substance supports this claim.
    • This is important because what cannot be counted cannot be individuated and identified. That is, if we do not know how much of what goes on is one individual thing (of a particular type) we can't say whether ‘it' has persisted, whether something we are encountering now is the same one we encountered earlier. A genuine entity, one whose history we can trace and which we can reidentify from one time to another, must be capable of being counted as one and distinguished from others of its kind at any point in its history.
    • What follows are five arguments with which a dualist might try to show that immaterial substances are distinct, definite, countable things. Notice that none seems to succeed in its purpose.
    • 1. Immaterial substance is conceived on an analogy with material substance. But the signal difference between them is that immaterial substances have no corporeal characteristics. So although individual material substances have boundaries and only one can occupy a given place at a given time, immaterial substances can have no boundaries we could use to distinguish one from another.
    • 2. A single human body will normally have a known compliment of organs (one heart, two lungs etc.) so another crude criterion (besides physical outline or boundary) is available if we are counting human beings. However, there are no immaterial organs that we know of in the immaterial mind so again there is no immaterial analogy we can draw to help with distinguishing and counting immaterial substances. There seems to be nothing to block Strawson's suggestion to dualist Professor X (discussed by Smith and Jones on 47) that there may be a thousand souls simultaneously thinking the thoughts his words express. Any number of (indistinguishable) immaterial minds might be associated with any one living human body or brain.
    • 3. The dualist is likely to say that it is the mind's contents which define the unique individual. Only you have the unique collection of thoughts, feelings, memories, preferences, prejudices, projects etc. which are your own. And this may well be true in fact. But of course one can easily imagine an exactly similar collection constituting or associated with a second mind. There is nothing logically impossible about the idea of legions of immaterial minds, all — as far as mental contents go — exactly alike to the minutest detail, being associated with any number of living human bodies you care to mention.
    • 4. In introspection, you seem to yourself to be a single subject whose experiences are united by self-consciousness7 with your memories and plans, emotions and feelings, into a single mind. But there is no guarantee that it is a single dualist mind you have access to in introspection. What would be the difference in ‘feel' between introspecting a single immaterial substance and introspecting several?
    • 5. Finally, it might be said that an immaterial substance may consist of just one portion of mind stuff. But who can say how much that is? The same difficulties (about how to count such things) afflict the notion of ‘a single portion' as afflict the notion of immaterial substance itself.
    • Since there is no way of distinguishing immaterial substances from one another and counting them, the conclusion seems difficult to escape that they are not genuine entities.
  6. Evolutionary8 considerations
    • Reading
      "Smith (Peter) & Jones (O.R.) - The Philosophy of Mind - An Introduction", 1986, pp. 49-52.
      "Churchland (Paul) - Matter & Consciousness", 1984, pp. 20-21.
    • The pictures given by Smith and Jones and Churchland of how the human species evolved are alike in all essential details. Both accounts stress that a gradual and entirely physical process of (mostly tiny) incremental changes compounding and compounding has, after many millions of years, produced a very complex organism with a nervous system which permits guidance of action apparently by thought. There seems no point at which immaterial mind stuff could, all at once, enter the picture. Humans have too many features that seem to require a mind in common with the species which are their evolutionary9 neighbours for it to seem plausible that, suddenly, with the emergence of the human species, immaterial substances began to have the crucial role dualists claim for them in thought, feeling, perception and conscious experience generally.
    • Many evolutionary10 theorists would maintain that there are no sudden lurches and jumps in the process of evolution11. They would claim that evolutionary12 history has not discovered any sudden appearances of fully developed complex mechanisms and structures. In early species, a very rudimentary stomach, say, or eye may be found from which gradually, over many millennia and through changing environments, can be traced the development of more and more complicated and sophisticated organs and structures evolving eventually into highly complex and specialised digestive or visual systems.
    • So too with the central nervous system and brain. It seems much more likely that the kinds of thoughts and feelings experienced by us developed out of the less sophisticated activities of the simpler brains and nervous systems of our evolutionary13 ancestors than that our cognitive capacities were somehow superadded with the introduction of an exclusively human spiritual substance.
  7. Activity
    • Consider the alternative view that perhaps immaterial substances are universal throughout sentient nature but that they have had to evolve in step with the natural creatures whose immaterial partners they are. What has this view to recommend it? What weak points do you think it has?
  8. Interaction between the immaterial and the physical
    • Reading
      "Churchland (Paul) - Matter & Consciousness", 1984, pp. 7-10.
      "McGinn (Colin) - The Character of Mind - An Introduction to the Philosophy of Mind", 1982, 23-25.
      "Priest (Stephen) - Theories of the Mind", 1991, pp. 31-34.
      "Smith (Peter) & Jones (O.R.) - The Philosophy of Mind - An Introduction", 1986, 53-59.
    • The single most imposing obstacle to the acceptance of substance dualism has always been the puzzle of mind/body interaction. Just in so far as a friend of substance dualism is able to persuade us of the utter metaphysical difference between material substance on the one hand and spiritual or immaterial substance on the other, so great will be the difficulty the dualist faces in trying to persuade us that these two radically different kinds of things could interact with one another.
    • And yet daily experience teaches us that such interaction is constant and undeniable. Every time you stub your toe (a physical occurrence), it appears that this physical event causes a mental event (your feeling of pain). Every time you experience feelings of hunger and thirst (mental occurrences) and are led by them to eat and drink (physical actions), it would seem that the mental has had an effect in the physical realm. How can a dualist account for this? Surely two things that are utterly, metaphysically, different cannot get any purchase on each other. Physical things can only exert physical pressure; mental things, only the non-physical influence of thought. As Churchland puts it, ‘How is this utterly insubstantial "thinking substance" to have any influence on ponderous matter?' (9).
    • In particular, critics of dualism very often baulk at the notion that any material or physical happening (like an event in your brain) could have an immaterial cause. And yet if dualism is correct, and if your mind ever affects what you do, then the brain events which start the train of physical events which issue at least in the muscle movements that accomplish your actions must have among their causes some events in your immaterial mind. But surely the realm of physical causes and effects is closed (see Smith and Jones 58) — that is, there are no non-physical sources of physical energy or impetus. It would go wholly contrary to the law of conservation of energy if any energy should come into the physical realm from outside, so to speak. Yet that is exactly what must happen if an immaterial mind is to have any power over the actions of its material body.
    • It would be wrong to end this chapter creating the impression that substance dualism, alone among theories of mind, has difficulty accounting for the relationship common sense tells us exists between mind and body. Every materialist14 theory that hopes to leave room for the causal efficacy of the mental must also face the difficulty that brain events seem sufficient all by themselves to explain any bodily activity they initiate. And this without reference to the thought, desire, choice or decision their human subject may regard as that movement's cause.
  9. Learning outcomes: After working through the reading materials and this chapter you should be able to:
    • Outline the four criticisms which critics have levelled at substance dualism, and .
    • Discuss them critically.
  10. Sample questions
    • Is there any way of counting immaterial substances? Why does it matter?
    • Can a dualist give a satisfactory account of mind/body interaction? If so, what is it? If not, why not?
  11. Tips on answering the sample questions
    • The first question is about the second criticism discussed in this chapter. You should:
      … First state Strawson's view that all genuine entities can be distinguished from one another in such a way as to be counted.
      … Then give and explain the five suggested ways immaterial substances can be counted.
      … Finally, give the objections which provide Strawson's ground for saying that ‘immaterial substance' does not designate a genuine entity.
    • The second question is the more general of the two and in some ways easier. It would be best to start by thinking which answer to the first part you actually believe — can the dualist explain mind/body interaction or not? Once you know your own mind, it will be easier to write a full answer and make use of what you know about the topic to deal with the second and third questions.


Part 1 (The Metaphysics of Mind and Body); Section 1 (Dualism); Chapter 4. Hard Copy in "Various - Papers on Religion Boxes (Heythrop)".

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