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papo   The third hypothesis
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Reduction to Open Individualism

by Iacopo Vettori - September 2016

Chapter 3: Criticism of the identity concept applied to persons

19. Personal identity, or the identity concept applied to persons, is different from the identity of objects, because it comes from our direct personal experience. The concept of identity applied to my person comes from the realization that I can directly control and feel sensations from a limited part of the outer world that I identify as “my body” or “me”. It is the existence of a mental world that allows us to assign an identity to our material counterpart, not the other way around. It is this connection that creates our experience of being discrete physical subjects, which is not reducible to a mere communication convention. (Note: Julian Jaynes in his book The Origin of Consciousness in the Breakdown of the Bicameral Mind suggests that anthropologically we gained the matching between the identity of our mind and the identity of our body during centuries of social evolution).

20. The concept of identity applied to objects derives from an arbitrary extension of the concept of identity that we apply to ourselves and then to other persons. But this view raises the question about the origin of the identity of our mental world. Have we to accept it as “given”? If personal identity cannot be anchored to the identity of something material or structural, then the identity concept in itself seems to be intrinsically dualistic. We will see that only Open Individualism can solve this question, avoiding all the problems related to dualistic theories, but for now let us suspend our judgement about the origin of personal identity, acknowledging that at the moment we have no complete theory of personal identity. Notwithstanding this, let us start examining the problems that arise when, once we accept that the identity concept comes from the direct experience of our personal identity, we continue thinking that every person has their own separate personal identity.

21. All reductionists agree that every mental phenomenon has a physical counterpart, but they have to face the fact that our direct experience of the existence of a mental world appears to be something like an unexpected and unnecessary phenomenon that arises from brain activity, which is expected to respect only physical laws. It is difficult to find a reason to deny that a fully materialist world could work the same without any mental world emerging from brain activity; we know that a mental world exists just because we have a direct experience of it, and then we assume that it is true also for other people. In fact, we infer that other people have conscious experiences based only on their behavior and, more recently, on our knowledge of the functioning of the brain. Because we can see that they act in about the same way that we do, we figure that everybody else has their own “experience of thinking” in the same way we have. Making this generalization we integrate the objective knowledge that we get from observation with the subjective experience of the mental world that we undergo in the first person. This is the main reason why Reductionism asserts that it is possible to map any mental state onto a specific physical brain state, but it does not justify the existence of the mental state. This is why reductionists have to say that mental phenomena “emerge” from the brain (whatever that may mean), and this is why the hard problem of consciousness described by David Chalmers is so hard to solve.

22. To avoid focusing the discussion on consciousness instead of personal identity, and thereby avoid the questions about various degrees and limits of consciousness, I will use the term “subjectiveness” instead of “consciousness” to refer to the experience of having a mind, a mental world that “emerges” from the brain of a living being. The term “subjectiveness” highlights that having a first-person point of view is what is missing in inanimate objects and is what is occurring in living beings, and for that reason they can be properly called “subjects” instead of “objects”. The mind, or the mental world that each of us experiences personally, can according to this terminology be called the “subjectivity phenomenon”; this term also refers to the lower levels of perception. The subjectivity phenomenon is originated by brain activity, but it does not exclude the possibility of other sources. This allows us to apply the discussion to a wider range of living beings instead of only to humans.

23. Because in a reductionist world, every mental state corresponds to some brain state, I will call the process that is able to transform a brain state into a mind state the subjectivity function”. The applying of the subjectivity function to a series of ordered brain states results in the appearance of a series of mind states that constitutes the mind or the “subjectivity phenomenon” as defined before. Each different brain, through the subjectivity function, originates an (apparently) numerically different instance of mind, which we usually identify as a subject with its own personal identity.

24. By referring to a “subjectivity function”, I do not mean that the mind is a passive result of a physical process that may be driven only by chance or necessity, but rather I just point out the strict correspondence between the brain and the mind in a reductionist sense. I do not exclude the possibility that mind may interact actively with physical world, even if this does not appear to be compatible with reductionism. This problem is related to free will and can be considered separately from the issues relating to subjectiveness and personal identity. I will discuss it in more detail at the end of this document, explaining how Open Individualism may help to manage this problem.

25. So far, we have seen how personal identity is not reducible to a mere communication convention like the identity of objects was: on the contrary, this is the basis on which we build our concept of identity. Even if we cannot imagine where to anchor our personal identities, we assume that in some way the identity of my mind is something definitely different from the identity of your mind. We are here at the same time, me and you and everybody else, so how on earth can we have the same personal identity? To see that even this trivial conviction has serious problems, we have to consider some cases that currently seem to belong only to science fiction, but actually in part are already possible and have already been discussed by many philosophers of the mind, and are summarized by Derek Parfit in Reasons and Persons. These cases are about the extreme possibilities that result from personal identity transforming, splitting and melding.

26. In Reasons and Persons, Derek Parfit describes a thought experiment called “the combined spectrum”, where the body and the brain and the psychological content of the brain of one person are gradually transformed into the body and the brain of another person. From a reductionist point of view, nothing else determines personal identity but the matter and the structure of the body and the brain (considering the psychological content as an expression of some physical structure in the brain). For this reason, he concludes that personal identity changes smoothly during the experiment, so that the person after the experiment has a completely different personal identity from the person before the experiment. He says that after a certain amount of transformation, the personal identity is not the original one, and yet it is not the final one. At some point in the spectrum, the resulting person will believe him or herself to be a different person from the original one. We may think that there is a sharp borderline between the two different personal identities, where the first one is suddenly replaced by the second one, but Parfit thinks that the change will happen smoothly, so at every intermediate step in the spectrum of the transformation, the resulting person is still the original one to some degree. But because the final person has been set to be a completely different person from the original, he excludes the possibility that anything of the original person may still survive at the far end of the spectrum, when the person has completely become the final person.

27. Parfit acknowledges that this thought experiment raises a problem. During our life, the matter that constitutes our body continuously changes, as does the structure of our body. The body and brain structure of a child are very different from the body and brain of the same individual when old, so much so that the differences are comparable to those existing between two different individuals. Parfit concludes that necessarily the personal identity of each individual changes gradually over the years. He is forced to this conclusion because he does want to keep reductionism and the personal identity concept together.

28. Here I want you to notice that Open Individualism could have already been deduced from this consideration, if we assume that the starting point and the end point of the imaginary transformation between two persons has no special role, and that therefore, they may well be considered to still be the same person, a possibility that Parfit excludes. He does not define any critical factor that necessarily determines if two people can or cannot be the same person: he just observes that one person could be smoothly transformed into another person, even a person arbitrarily chosen from among the ones already in existence, and from this fact he deduces that the original and the final person necessarily have to be two different persons. But such a critical factor may well exist: it could be a percentage of changes in the individual characteristics, and/or individual faculties, that together cause the lacking of the psychological connectedness needed to consider the personal identity to still be the original one. Open Individualism may follow even from this view, if we hypothesize that differences in psychological characteristics have no influence, and that the only psychological faculty required to maintain enough psychological connectedness to consider the personal identity to still be the same is the bare faculty of “being a subject”, and therefore “having a brain supporting the subjective phenomenon”. This would eliminate any chance of finding the personal identity concept in a reductionist way, but there would be no need to appeal to non-reductionist theories: Open Individualism can be achieved by giving up the personal identity concept, denying that any absolute “identity” may ever be defined, and therefore believing that all of our apparent personal identities should be considered undefinable. We will see later how this can be compatible with the mere fact that there exist many physically separate individuals.

29. The possibility of mind splitting by surgical brain splitting is described by Parfit and other authors, referring to the surgical separation of the two hemispheres of the brain. In the 1960s experiments with this procedure were carried out to cure some severe epilepsy cases. It turned out that people who underwent this operation behaved like they were two persons sharing the same body. Each half of the split brain seems to generate its own mind.

30. The real cases were irreversible, but it is possible to imagine that the communication between the two hemispheres was only temporarily inhibited. Parfit and other authors like Roger Penrose tried to imagine how it would be to experience such temporary mind splitting, and wondered whether it would preserve our personal identity. They agree that it would be preserved, at least when the splitting has a brief duration.

31. But reasoning about a temporary splitting of our brain into two independent hemispheres requires us to imagine that our mind becomes both the mind generated by the left hemisphere and the mind generated by the right hemisphere. This seems to require the simultaneous existence of two different personal identities, so my original personal identity seems to not be sufficient to explain the case. For this reason, some thinkers prefer to argue that actually we always live with two different personal identities, one for each hemisphere, even if we are not aware of it.

32. We also have to know that there exist some injured people who live with only half of their brain functioning. If we imagine that we could experience a temporary switching off of half of our brain, quickly followed by a switching on, nobody would question that the experiment would preserve our personal identity.

33. Moreover, we may also imagine that the two halves of the split brain may be transplanted into two different bodies. The resulting two people may live and act independently. In this scenario, it seems absolutely beyond dispute that this would imply the simultaneous existence of two different personal identities. But it is difficult to imagine what would happen to my original personal identity, considering that most of us probably think that it is possible to survive if I had half of my brain switched off, and then the functioning half transplanted into another body. It is the simultaneous existence of two legitimate candidates to being my future self that undermines my confidence in the survival of my personal identity.

34. We may imagine that the resulting two people are left to live their lives entirely without ever being re-joined in the original body, but we may also imagine again transplanting the two hemispheres back into the original body, and reconnecting them to again form the original whole brain. In this case, we may think that the original personal identity will reappear. This is called “mind melding”, and can be generalized using entire brains.

35. Mind melding represents the complementary hypothesis to mind splitting: it results from imagining that two or more brains could be connected together to form a bigger brain, with a unified brain activity, so that it will generate a single mind. There already exist some devices that allow us to detect brain activity, and there also exist some rudimentary devices that can interfere with our brain activity, so that we can perceive a signal sent directly to our brain. And actually, some experiments with mice have demonstrated that it is possible to join the brains of two or more mice so that they form a brainet behaving as though it generated a single shared mind (see the article by Dr. Karen S. Rommelfanger, Emory University, at

36. Imagine connecting your brain to a device that allows many people to directly share all the signals of their brains, so that they act like a single bigger brain. How do you think this would feel? Once our brain is connected with many others, so that the bigger-brain activity becomes a single, synchronized activity, we have to conclude that all participants will have a single shared mind, so that all the participants will have the very same personal identity. This experience would not be like to meeting some friends at a party: we have to think that the resulting mind would be unable to discern what brain it comes from. Because it would result from a single activity of all the connected brains, it would be equally generated by all of them. In the same way, after a temporary splitting of your brain hemispheres, you would not find yourself thinking “I was the left-hemisphere-generated-mind that now has been reconnected with the right-hemisphere-generated-mind to re-form my entire mind”. You would simply think, with some relief, that finally your mind is once again being generated by both the hemispheres of your brain. And similarly, once the melded mind decides to dissociate the brain that you previously considered to be “your brain”, you will find yourself again alone with your body, brain and mind, but certainly shocked by the experience you underwent, and perhaps doubting whether your personal identity is really the very same one you had before.

37. The disconcert regarding these imaginary experiences comes from our need to think that both mind splitting and mind melding have to instantly create and destroy one or more personal identities. But our need to imagine that many personal identities are involved in these processes is dictated by our inability to accept that two or more coexisting minds may have the same personal identity. And actually, if we were to accept this hypothesis, we would not need to postulate any personal identity at all: it would become a concept that refers only to something illusory. But we have to figure out what it might mean that two or more minds may have the same personal identity, especially when they exist simultaneously.

Continue on the next page "Chapter 4: External time and Subjective times".


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