From property dualism to substance dualism

From property dualism to substance dualism

All the arguments so far in this section have been either arguments for property dualism only, or neutral between property and substance dualism. In this subsection, and in section 4.5 we will consider some arguments that have been proposed in favour of substance dualism.The ones in this section can be regarded as preliminaries to that in 4.5 and they centre on discontent with property dualism in its Humean form.
Hume is generally credited with devising what is known as the 'bundle' theory of the self (Treatise Book I, Part IV, section VI), according to which there are mental states, but no further subject or substance which possesses them. He famously expresses his theory as follows.

اقتباس :: ...when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade,love or hatred, pain or pleasure. I can never catch myself at any time without a perception, and can never observe any thing but the perception.

Nevertheless, in the Appendix of the same work he expressed dissatisfaction with this account. Somewhat surprizingly, it is not very clear just what his worry was, but it is expressed as follows:

اقتباس :: In short there are two principles, which I cannot render consistent; nor is it in my power to renounce either of them, viz. that all our distinct perceptions are distinct existences, andthat the mind never perceives any real connection between distinct existences.

Berkeley had entertained a similar theory to the one found in Hume's main text in hisPhilosophical Commentaries, (Notebook A, paras 577-81), but later rejected it for the claim that we could have a notion, though not an idea of the self. This Berkeleian view is expressed in more modern terms by John Foster.

اقتباس :: A natural response to Hume would be to say that, even if we cannot detect ourselves apart from our perceptions (our conscious experiences)we can at least detect ourselves in them...Surely I am aware of [my experience], so to speak, from the inside - not as something presented, but as something which I have or as the experiential state which I am in...and this is equivalent to saying that I detect it by being aware of myself being visually aware. (1991: 215)

There is a clash of intuitions here between which it is difficult to arbitrate. There is an argument that is meant to favour the need for a subject, as claimed by Berkeley and Foster.
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[*]If the bundle theory were true, then it should be possible to identify mental events independently of, or prior to, identifying the person or mind to which they belong.

[*]It is not possible to identify mental events in this way.

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Therefore,
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[*]The bundle theory is false.

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E. J. Lowe (1996) defends this argument and argues for (2) as follows.

اقتباس :: What is wrong with the [bundle] theory is that...it presupposes, untenably,that an account of the identity conditions of psychological modes can be provided which need not rely on reference to persons. But it emerges that the identity of any psychological mode turns on the identity of the person that possesses it. What this implies is that psychological modes are essentially modes of persons, and correspondingly that persons can be conceived of as substances.

To say that, according to the bundle theory, the identity conditions of individual mental states must be independent of the identity of the person who possesses them, is to say that their identity is independent of the bundle to which they belong. Hume certainly thought something like this, for he thought that an impression might 'float free' from the mind to which it belonged, but it is not obvious that a bundle theorist is forced to adopt this position. Perhaps the identity of a mental event is bound up with the complex to which it belongs. That this is impossible certainly needs further argument.
Hume seems, however, in the main text to unconsciously make a concession to the opposing view, namely the view that there must be something more than the items in the bundle to make up a mind. He says:

اقتباس :: The mind is a kind of theatre where several perceptions successively make their appearance; pass, re-pass, glide away and mingle in an infinite variety of postures and situations.

Talk of the mind as a theatre is, of course, normally associated with the Cartesian picture, and the invocation of any necessary medium, arena or even a field hypostasize some kind of entity which binds the different contents together and without which they would not be a single mind. Modern Humeans - such as Parfit (1971; 1984) or Dainton (2008) - replace the theatre with a co-consciousness relation. So the bundle theorist is perhaps not as restricted as Hume thought. The bundle consists of the objects of awareness and the co-consciousness relation (or relations) that hold between them, and I think that the modern bundle theorist would want to say that it is the nexus of co-consciousness relations that constitutes our sense of the subject and of the act of awareness of the object. This involves abandoning the second of Hume's principles. that the mind can never perceive any connection between distinct existences, because the co-consciousness relation is something of which we are aware. The Humean point then becomes that we mistake the nexus of relations for a kind of entity, in a way similar to that in which, Hume claims,we mistake the regular succession of similar impressions for an entity called an enduring physical object. Whether this really makes sense in the end is another matter. I think that it is dubious whether it can accommodate the subject as agent, but it does mean that simple introspection probably cannot refute a sophisticated bundle theory in the way that Lowe and Foster want. Hume's original position seems to make him deny that we have any 'sense of self' at all, whilst the version that allows for our awareness of the relatedness accommodates it, but explains how it can be an illusion. The rejection of bundle dualism, therefore, requires more than an appeal to our intuitive awareness of ourselves as subjects.We will see in the next section how arguments that defend the simplicity of the self attempt to undercut the bundle theory.

4.5 Arguments from Personal Identity

There is a long tradition, dating at least from Reid (1785), for arguing that the identity of persons over time is not a matter of convention or degree in the way that the identity of other (complex) substances is and that this shows that the self is a different kind of entity from any physical body. Criticism of these arguments and of the intuitions on which they rest, running from Hume to Parfit (1970: 1984), have left us with an inconclusive clash of intuitions. The argument under consideration and which, possibly, has its first statement in Madell (1981), does not concern identity through time, but the consequences for identity of certain counterfactuals concerning origin. It can, perhaps, therefore, break the stalemate which faces the debate over diachronic identity. The claim is that the broadly conventionalist ways which are used to deal with problem cases through time for both persons and material objects, and which can also be employed in cases of counterfactuals concerning origin for bodies, cannot be used for similar counterfactuals concerning persons or minds.
Concerning ordinary physical objects, it is easy to imagine counterfactual cases where questions of identity become problematic. Take the example of a particular table. We can scale counterfactual suggestions as follows:

This table might have been made of ice.
This table might have been made of a different sort of wood.
This table might have been made of 95% of the wood it was made of and 5% of some other wood.

The first suggestion would normally be rejected as clearly false, but there will come a point along the spectrum illustrated by (i) and (iii) and towards (iii) where the question of whether the hypothesised table would be the same as the one that actually exists have no obvious answer. It seems that the question of whether it ‘really’ is the same one has no clear meaning: it is of, say, 75% the same matter and of 25% different matter; these are the only genuine facts in the case; the question of numerical identity can be decided in any convenient fashion, or left unresolved. There will thus be a penumbra of counterfactual cases where the question of whether two things would be the same is not a matter of fact.
Let us now apply this thought to conscious subjects. Suppose that a given human individual had had origins different from those which he in fact had such that whether that difference affectedwho he was was not obvious to intuition. What would count as such a case might be a matter of controversy, but there must be one. Perhaps it is unclear whether, if there had been a counterpart to Jones' body from the same egg but a different though genetically identical sperm from the same father, the person there embodied would have been Jones. Some philosophers might regard it as obvious that sameness of sperm is essential to the identity of a human body and to personal identity. In that case imagine a counterpart sperm in which some of the molecules in the sperm are different; would that be the same sperm? If one pursues the matter far enough there will be indeterminacy which will infect that of the resulting body. There must therefore be some difference such that neither natural language nor intuition tells us whether the difference alters the identity of the human body; a point, that is, where the question of whether we have the same body is not a matter of fact.
How one is to describe these cases is, in some respects, a matter of controversy. Some philosophers think one can talk of vague identity or partial identity. Others think that such expressions are nonsensical. There is no space to discuss this issue here. It is enough to assume, however, that questions of how one is allowed to use the concept of identity effect only the care with which one should characterize these cases, not any substantive matter of fact. There are cases of substantial overlap of constitution in which that fact is the only bedrock fact in the case: there is no further fact about whether they are ‘really’ the same object. If there were, then there would have to be a haecceitas or thisness belonging to and individuating each complex physical object, and this I am assuming to be implausible if not unintelligible. (More about the conditions under which haecceitas can make sense will be found below.)
One might plausibly claim that no similar overlap of constitution can be applied to the counterfactual identity of minds. In Geoffrey Madell's (1981) words:

اقتباس :: But while my present body can thus have its partial counterpart in some possible world, my present consciousness cannot. Any present state of consciousness that I can imagine either is or is not mine. There is no question of degree here. (91)

Why is this so? Imagine the case where we are not sure whether it would have been Jones' body—and, hence, Jones—that would have been created by the slightly modified sperm and the same egg. Can we say, as we would for an object with no consciousness, that the story something the same, something different is the whole story: that overlap of constitution is all there is to it? For the Jones body as such, this approach would do as well as for any other physical object. But suppose Jones, in reflective mood, asks himself ‘if that had happened, would I have existed?’ There are at least three answers he might give to himself. (i) I either would or would not, but I cannot tell. (ii) There is no fact of the matter whether I would or would not have existed: it is just a mis-posed question. (iii) In some ways, or to some degree, I would have, and in some ways, or to some degree, I would not. The creature who would have existed would have had a kind of overlap of psychic constitution with me.
The third answer parallels the response we would give in the case of bodies. But as an account of the subjective situation, it is arguable that this makes no sense. Call the creature that would have emerged from the slightly modified sperm, ‘Jones2’. Is the overlap suggestion that, just as, say 85% of Jones2's original body would have been identical with Jones', about 85% of his psychic life would have been Jones'? That it would have been like Jones'—indeed that Jones2 might have had a psychic life 100% like Jones'—makes perfect sense, but that he might have been to that degree, the same psyche—that Jones ‘85% existed’ —arguably makes no sense. Take the case in which Jones and Jones2 have exactly similar lives throughout: which 85% of the 100% similar mental events do they share? Nor does it make sense to suggest that Jones might have participated in the whole of Jones2's psychic life, but in a rather ghostly only 85% there manner. Clearly, the notion of overlap of numerically identical psychic parts cannot be applied in the way that overlap of actual bodily part constitution quite unproblematically can.
This might make one try the second answer. We can apply the ‘overlap’ answer to the Jones body, but the question of whether the minds or subjects would have been the same, has no clear sense. It is difficult to see why it does not. Suppose Jones found out that he had originally been one of twins, in the sense that the zygote from which he developed had divided, but that the other half had died soon afterwards. He can entertain the thought that if it had been his half that had died, he would never have existed as a conscious being, though someone would whose life, both inner and outer, might have been very similar to his. He might feel rather guiltily grateful that it was the other half that died. It would be strange to think that Jones is wrong to think that there is a matter of fact about this. And how is one to ‘manage’ the transition from the case where there is a matter of fact to the case where there is not?
If the reasoning above is correct, one is left with only the first option. If so, there has to be an absolute matter of fact from the subjective point of view. But the physical examples we have considered show that when something is essentially complex, this cannot be the case. When there is constitution, degree and overlap of constitution are inevitably possible. So the mind must be simple, and this is possible only if it is something like a Cartesian substance.

From property dualism to substance dualism