Theo Todman's Web Page - Paper Abstracts

Notes

1. This paper is an entertaining amalgam of TEs¹ that Dennett admits are indebted to essays in "Rorty (Amélie Oksenberg), Ed. - The Identities of Persons", in particular to:-
   1. "Lewis (David) - Survival and Identity",
   2. "Parfit (Derek) - Lewis, Perry, and What Matters",
   3. "Perry (John) - The Importance of Being Identical", and
   4. "Shoemaker (Sydney) - Embodiment and Behavior".
2. The conceit of the paper is that Dennett is giving a talk describing various vicissitudes beloved of philosophers of personal identity that he has survived (maybe) and one of which occurs during the speech itself.
3. For dubious reasons that need not detain us, Dennett has had his brain₂ removed for safe-keeping and placed in a vat³, from where it controls his body by remote control. Pairs of radio transceivers attached to “nerve stumps in the empty cranium” and “the brain” connect up each “input and output pathway” so that – effectively – the nerves are stretched₄.
4. After the operation, Dennett initially feels a little “light headed₅”, but is otherwise fine and is taken to see his brain floating in its vat of nutrients, where it is almost covered₆ with “printed circuit chips, plastic tubules, electrodes, etc.”.
5. To prove that the BIV is Dennett’s, he’s invited to flip₇ a switch, after which he immediately₈ “slumps groggy and nauseated”, and upon which an assistant flips the switch back, allowing Dennett to “recover his equilibrium and composure”.
6. Dennett now tries to consider where he is (the title of the paper). Despite believing – as a “firm physicalist”⁹ – that “the tokening of his thoughts occurred somewhere in his brain”, he couldn’t convince himself that he – Dennett – was in the vat. Rather₁₀, he was outside where he stood.
7. Also, while he has no trouble with imagining various locations for “there”, he does not have the same flexibility for “here”.
8. To try to make things clearer, he adopts the “standard philosophical ploy” and names things: his brain “Yorick”, (the rest of) his body “Hamlet”, while he himself remains “Dennett”. So, where is he, and where is the thought “where am I?” tokened – in his brain (in the vat), or between his ears (“where it seems₁₁ to be tokened”)? Dennett claims that he has no trouble with the temporal coordinates of thought-tokens, only their spatial coordinates.
9. So where is he (Dennett)? He thinks of three possibilities:-
   1. Where Hamlet goes: Dennett rules this out immediately because of the Brain Transplant¹² intuition: we go with our brain because it’s responsible for our psychology. A brain transplant¹³ is really₁₄ a body transplant¹⁵.
   2. Where Yorick goes: Dennett says this isn’t appealing either – how can he be in a vat when he seems to be walking around? Dennett borrows from Locke the idea that personal identity is a forensic¹⁶ matter, and considers what US State he’d be tried in if Hamlet committed a crime₁₇, and considers whether Hamlet or Yorick would “do the time₁₈”, and where.
   3. Wherever Dennett thinks he is: the person is where his point of view (POV) says he is. Dennett rather confusingly₁₉ spells this out by saying that “the location of the POV (which is determined internally by the content of the POV₂₀) is the location of the person”. Dennett points out that this would make one’s location infallibly known, yet one has sometimes got lost. Worse, while lost in the woods, one could – at least in normal circumstances – confidently assert that one was in one’s body, but in these unusual circumstances Dennett wasn’t so sure.
10. Dennett continues his discussion of PoVs:
    1. PoV has something to do with location, but the content of one’s PoV isn’t the same as (or even determined by) the content of one’s beliefs or thoughts₂₁.
    2. Cinerama viewers suffer illusory shifts in points of view.
    3. Other PoV-shifts are less illusory: for instance the use of feedback-controlled mechanical arms in the nuclear industry; they can shift their PoV into the isolation chamber, but are not fooled into false beliefs, and are not transferring themselves there.
    4. There’s a final paragraph in this section where Dennett soliloquises on practice and training one’s PoV:-
       1. If I were really in the vat, I could train myself habitually to adopt that PoV – images of me floating there and beaming volitions to my body elsewhere.
       2. He suggests the ease of this task is independent of the truth of the brain’s location, and might have become second nature had he practiced before the operation – indeed the reader could try it out₂₂.
11. Dennet now helpfully explores the consequences of the TE:
    1. He repeats the suggestion about initial dizziness – again without explanation. He says this is so only “initially”, and that he soon habituates himself to his new situation, which is “well-nigh indistinguishable” from his former circumstances. However, …
    2. Due to the finite speed of light, he suffers minor coordination difficulties on account of feedback loops. He gives the example of being rendered speechless by hearing your own voice repeated, as in an echo₂₃. He’s unable to track a moving object – such as a ball – when brain and body are more than a few miles apart.
    3. An advantage – he says – is that he can drink any amount of alcohol, which now only warms his gullet, though is still corrodes his liver.
    4. However, while he can take aspirin orally for a sprain, persistent pain requires codeine to be administered to his brain in vitro₂₄.
12. Dennett now sets off on his mission, leaving his brain hundreds of miles away.
    1. On the way, Dennett decides that he has become a “scattered²⁵” person, rather than that – as he had thought unreflectively – he’d just left his brain behind.
    2. He gives a very poor analogy₂₆: his being in two places at the same time – both in the vat and outside it – is just like someone standing astride a boundary between two states.
    3. Dennett says that while this now seemed obviously true, the philosophical question to which it was supposedly the right answer now seemed less important, as occasionally happens in philosophy.
    4. Yet, the answer was not entirely satisfying. His question was neither “where are my parts” nor “what is my current PoV”; for, there was a sense in which he believed that he and not merely most of him had gone off on his mission.
13. When he gets down to work on his mission, all’s well until his transceivers start to fail, and he loses his senses (ie. in turn he goes deaf, dumb, blind and paralysed).
    1. He is now to consider himself disembodied in his vat.
    2. Dennett claims that his body is still alive – in that the heart and lungs are still working – but that it’s otherwise “as dead as the body of any heart₂₇ transplant²⁸ donor”.
    3. The shift in perspective now seemed entirely natural. He could still imagine₂₉ himself back in his body, but it was an effort now he’d lost all contact with it.
14. Dennett now has what I presume is a little joke. His alter ego pretends to have a revelation to the effect that “he has discovered the immateriality of the soul based on physicalist³⁰ principles and premises”.
    1. The “proof” is that when the last transceiver failed, “he” – or at least his massless soul or mind – travelled hundreds of miles at the speed of light to take up residence in his vat, with no increase in mass.
    2. His PoV had lagged behind somewhat, but this has already been shown to be indirectly correlated with location.
    3. He thinks a physicalist³¹ philosopher could only disagree with his “revelation” by banishing all talk of persons³², but personhood is too embedded in everyone’s worldview to be jettisoned, any more than adopting an anti-Cartesian₃₃ “non sum”.
15. He says this “revelation” tided him over as panic – and even nausea₃₄ – swept over him when he realised his “condition”.
    1. He’s then put into a “dreamless sleep”³⁵ to be awakened by music fed directly into his auditory nerve.
    2. He is assured that efforts are being made to re-embody him, and a year later he does indeed find himself “housed” in a different body.
    3. He notes that philosophers₃₆ speculate that the acquisition of a new body leaves one’s person intact.
    4. He admits there are physical changes to get used to, but any personality changes are no worse than those encountered by those undergoing plastic surgery or sex change, when no-one doubts the persistence of the person.
16. Dennett names his new body “Fortinbras” and goes₃₇ to visit Yorick, his brain in its vat.
    1. Once there, he flips the transceiver switch but – rather than “slumping” as previously – nothing happens; he notices no difference, nor when the switch is flipped back.
    2. The “explanation” is that – even before his first operation₃₈ – a “computer duplicate”³⁹ brain had been created.
    3. This “brain” – named “Hubert”, and running on a “giant computer” – reproduced both the information processing structure and computational speed of his brain (Yorick) and had been running in parallel even before his “mission”.
    4. So, the story goes that sensory input from Hamlet – his former body – was – on receipt by the transceivers – sent both to Yorick (his brain) and to the “computer’s array of inputs”. Also, while output from Yorick was sent to Hamlet, it was also stored and compared with that from Hubert.
    5. Over time, the outputs were identical and synchronous, which provided empirical evidence – if not proof – that Yorick’s functional structure had been successfully copied₄₀.
    6. It is now revealed that Hamlet had been destroyed in the course of the failed mission, but Hubert has been kept₄₁ synchronised with Yorick.
17. Now there is a second switch that is presently set to have Hubert control Fortinbras.
    1. Dennett is asked to flip the switch so that control is passed back to Yorick – he feels nothing₄₂ – and then to prove that Yorick really is now in control, is asked to flip the transceiver switch. Fortinbras immediately starts to slump, but recovers when it is flipped back.
    2. Dennett is left to fiddle with the control switch, and never notices any difference, even if it’s done in mid-sentence₄₃.
    3. So, it is suggested – Dennett now has a “spare₄₄ brain” should anything happen to Yorick.
    4. It’s noticed (in passing₄₅) that wear and tear to Fortinbras has no debilitating effect on either brain.
18. The TE moves on to the further thought about what would₄₆ happen if one of Hubert and Yorick were detached from Fortinbras and hitched up to another body – Rosencrantz, say.
    1. Then, there would be two persons each claiming to be Dennett – but which₄₇ one would be?
    2. The usual arguments are rehearsed:
       1. The Yorick-brained one has causal priority and was originally intimately connected to Hamlet. Dennett (purports to) downplay this as two legalistic for metaphysical purposes.
       2. For, imagine that Hubert had been driving Fortinbras for years, with Yorick as a “spare₄₈”. He alleges that Hubert-Fortinbras would then have “squatter’s rights” to be legally accounted the true Dennett.
    3. “Dennett” claims that his intuition is that he would survive if either₄₉ combination survived, but would “have mixed emotions about whether he should want both to survive”.
19. We now have the usual discussion of the problems of fission⁵⁰.
    1. Two Dennetts would be abhorrent (to Dennett) firstly for social reasons (shared wife, salary, …)
    2. Additionally, Dennett doesn’t like the idea of someone else knowing so much about him.
    3. However, those in the lab try to persuade him that there’s a plus side – he’d be able to do twice as much.
    4. Dennett isn’t sure he’d take up the offer₅₁, and isn’t sure it’s being offered to him₅₂ in the first place.
20. Retreating from the fission question, Dennett is more worried by the thought of one of the brains becoming detached₅₃ from Fortinbras.
    1. So, he asks for reassurance that no-one can fiddle with either the transceiver or master switch.
    2. He says this request is both₅₄ driven by self-interest and altruism.
    3. So, we are led to believe, Dennett has the master switch about his person (the local ones – controlling the environment for Yorick (and, presumably, access to the transceiver switch) and the power supply for Hubert - are “locked down”) and he checks all is well with both brains occasionally by flipping the master switch in the presence of someone who will flip it back should he flip to Yorick, and Yorick’s transceiver be set to “off”.
    4. For, in the latter case, while he’d have sensory input from Fortinbras, he’d not be able to control₅₅ his body.
    5. It is said that the master switch is unmarked, so Dennett never knows whether Yorick or Hubert is in charge of Fortinbras.
    6. If this means that Dennett₅₆ doesn’t know who he is, then
       1. This doesn’t make much of a dent in Dennett’s sense of who he is – his “essential Dennettness₅₇”, and
       2. This just shows that the question is of less interest than philosophers have claimed.
21. So, he gives the master switch another flip and there’s an explosion of complaint from Fortinbras₅₈!
    1. Two weeks ago, the two brains drifted slightly apart, and then the differences snowballed because the brains were then in a different receptive state for identical sets of input from the single body (Fortinbras).
    2. Hence, the illusion that Yorick (or Hubert) was in control of “his” body was dissipated. It was like being carried around in a cage - like being possessed – hearing himself say things he didn’t mean to say, and seeing his hands do things he’d not intended.
    3. “His brother” would scratch “our itches” – but not in the way Dennett would have, and would keep him awake
       • On reflection, I think this is a correct scenario.
       • While both Yorick and Hubert receive the same itches from Fortinbras – so neither should be surprised (or wakened) by tossing and turning on that account,
       • However, tossing and turning may be instigated by worries in “the other’s” mind, and if these worries are not shared, the tossing and turning would be inappropriate and awakening.
       with his tossing and turning. He’d been “in purgatory” – on the verge of a nervous breakdown – carried around helplessly by the other’s frantic round of activities and sustained only by the thought that eventually the other would flip the switch, and it’d be his turn for torment.
    4. So, it’s now the other’s turn – but at least he knows that “Dennett” knows he’s “in there” disconnected – which was not the case for “Dennett” himself.
22. The current problem can only be resolved by getting another body for “the other”:-
    1. Otherwise, the situation is like an expectant mother – “eating₅₉ – or at any rate tasting, smelling, seeing – for two”.
    2. Who keeps the current body (Fortinbras) is to be decided₆₀ by the flip of a coin, and the other can have a choice of bodies.
23. “Dennett” then sits down after making the final remark that – while the talk isn’t exactly what he’d have said – it’s entirely true.