Oxford Scholarship Online
- Most arguments for the Psychological Approach are based on the conviction that anyone who got your psychological features would be you.
- The possibility of fission proves this conviction false.
- Those who think that identity has no practical importance will find it even more difficult to argue for the Psychological Approach.
Sections
- The Transplant1 Intuition
- Whole-Brain Transplants2
- Fission and Hemispherectomy
- Prudential Concern
- Moral Responsibility
- The Treatment Argument
- The Same Person
- Practical Consequences of the Biological Approach
Annotations3
- The Transplant4 Intuition
- Olson wants to give the arguments in favour of the PV5 for two reasons:-
- If there are compelling arguments for a theory, difficulties are merely opportunities for further research. So, Olson must show that the arguments for the PV6 are unpersuasive.
- It would be “gratifying” to find what has led astray “the great many thoughtful and intelligent philosophers” who have accepted the PV7.
- Olson will attempt both – by arguing that the PV8 rests on practical considerations that:-
- Do not provide clear support for the PV9, and
- May well be compatible with the BV10.
- Olson rehearses a variant of the sort of story that – he says – most arguments for the PV11 are based on:-
- The story is a variant of Locke’s “Prince and Cobbler”, but in this case Prince’s psychology is transferred to Cobbler’s head by means of a cerebrum12 transplant13, Cobbler’s cerebrum being destroyed14.
- Two human beings15 result from this – Brainy and Brainless.
- Brainy: Has Cobbler’s body – so looks like him, but has Prince’s memories and character, but remembers nothing of Cobbler’s past.
- Brainless: has Cobbler’s body, is alive, but has no psychology – he’s effectively in a PVS16.
- So, what has happened to Prince?
- Many “intuit” that he goes with his organ of cognition. Despite physical appearances to the contrary, Brainy is Prince, and believes – indeed – himself so to be.
- The first thing Brainy will want to know when he wakes up17 is why his new body is strange to him, and what happened to his old one.
- And what has happened to Cobbler?
- Olson doesn’t – at this point – discuss this.
- But – since Prince occupies Cobbler’s body – we may presume Cobbler is no more – he ceased to exist when his cerebrum was destroyed18.
- Who is Brainless?
- Brainless looks like Prince, but has little of what made Prince “Prince”. Indeed, he’s not a person at all if personhood requires certain mental powers.
- If Prince’s cerebrum19 had not been transplanted20 but simply destroyed, that would have been the end of Prince – who would be just like Brainless in our story.
- So, Olson constructs an argument for the PV21 as follows:-
- Prince – in the transplant22 story – is Brainy.
- So, one survives over time iff one’s mental contents and capacities are preserved (perhaps with further constraints23).
- Olson calls the inclination – the hunch or pull to say that Prince survives as Brainy the Transplant24 Intuition (hereafter TI).
- One could also argue for the PV25 from the intuition that Prince does not survive as Brainless – the Vegetable Intuition.
- However, Olson will focus on the TI because it has received more attention26 – and if we can resist this intuition, the other will be easy pickings.
- Olson rejects the PV27 despite feeling the pull of the TI:-
- Because he accepts the BV, he is committed to rejecting the premise of the TI – you do not “go with your cerebrum”28, but simply lose your organ of thought as you would your liver. Prince is not Brainy but Brainless.
- He rejects the intuition because he believes – for other theoretical reasons to be laid out in later chapters – that Prince is a living organism, and that no living organism was once Prince and later Brainy.
- In addition, supporters of the PV29 have to defend their intuition against counter-intuitive consequences.
- Olson now provides – in summary – some excellent arguments as to why the TI has a “pull”. It relies on some principles that may well be true, but which the BV can also accommodate:-
- Prince should be providentially concerned about what happens to Brainy rather than Brainless.
- Brainy is morally responsible for Prince’s actions, but not for Cobbler’s.
- Everyone would feel compelled to treat Brainy as Prince.
- All these practical concerns are perfectly valid, but don’t require numerical identity30. Olson will postpone their discussion until Section IV.
- He will now proceed to:-
- Section II: Discuss why the version of the TI just presented differs from that usually offered, and then
- Section III: Argue that the conclusion of the TI argument for the PV31 doesn’t follow from its premise.
- Whole-Brain Transplants32
- Why has Olson used a cerebrum transplant33 rather than a WBT34 as his TE? We’re referred to "Van Inwagen (Peter) - Brain Transplants".
- His reason – of course – is that a cerebrum transplant35 differentiates supporters of the PV36 from those of the BV.
- When the cerebrum37 is removed, the relict is clearly a living animal, but this is not so when the whole brain38 – including the brain-stem – is removed. The whole brain is not “just another organ” – because of its regulatory function. Without it, the animal is dead – a corpse39.
- This has led to some to argue that the whole brain is – once removed – a maximally-mutilated animal40 – still alive, initially at least.
- So, the Whole Brain Transplant41 Intuition – that “you would go with your brain” might be consistent with Animalism42.
- However, this intuition is commonly held for the wrong reason. We don’t “go with our brain” because it is the bearer of our psychology, and the recipient of my brain is psychologically continuous with me, but because it is a pared-down animal.
- Because of this confusion – and because anyone who holds the Whole Brain Transplant43 Intuition for psychological reasons will also hold the (Cerebrum)44 Transplant45 Intuition to the same degree, Olson is right to focus on the latter.
- Fission and Hemispherectomy
- The TE in the previous section is varied so that the two hemispheres46 are transplanted47 into different skulls – resulting in Lefty and Righty.
- Since both Lefty and Righty are psychologically and physically continuous with the donor, they are both perfect candidates for being that person.
- However, as they are not identical to one another, the transitivity of identity says that they cannot both be identical to the donor.
- There seems to be no principled reason why you should be one rather than the other.
- So, you are neither, contrary to the transplant48 intuition, unless there is some brute fact that says you are one rather than the other.
- Some claim there is such a fact:-
- The suggestion is that the two hemispheres aren’t equipollent, but are differently specialized, so that one might be more closely psychologically continuous with the donor than the other, who might persist as the closest continuer49.
- Olson’s response is that the division of labour between the hemispheres is an accidental feature50 of the case, and is differently marked in some people than others. Some might be equipollent.
- Another response is that – while agreeing that Lefty and Righty are indeed distinct individuals – we should insist that both existed before the operation.
- We are referred to:-
→ "Perry (John) - Can the Self Divide?"
→ "Lewis (David) - Survival and Identity"
→ "Noonan (Harold) - Personal Identity", p. 153f51
→ "Robinson (John) - Personal Identity and Survival"
- Olson thinks that this view – that there “always two of you” – whatever it’s theoretical merits – undermines some of our most fundamental beliefs about ourselves.
- He claims that – if you are to fission in the future – then there was never “you” but only Lefty and Righty all along – two people who were exactly like you52. He claims that – on John Perry’s view – there were always three individuals, one of which becomes a scattered object53 after the fission.
- Olson claims that before the fission, the reference of “I” is both Lefty and Righty, so that any future claim where Lefty and Righty’s actions differ is false54.
-
- Prudential Concern
- Moral Responsibility
- The Treatment Argument
- The Same Person
- Practical Consequences of the Biological Approach
In-Page Footnotes
Footnote 3:
- In these Notes, I’ve not been especially careful to distinguish Olson’s points from my own, nor even Olson’s points here from those he makes elsewhere.
- See also the general disclaimer.
- This write-up is logged as a Paper Abstract rather than a Write-up Note. This is contrary to my current standard, and I will make the appropriate adjustment when I’ve completed annotating the whole book.
Footnote 14:
- The transplant intuition would be strengthened were Cobbler’s cerebrum removed to a vat of nutrients so that his mental life continues. We’d then be even less insistent that Brainy is Cobbler.
- Olson follows the standard usage of referring to both cerebral hemispheres as “the cerebrum”.
- Transplanting single hemispheres raised the possibility of fission, but that comes later! See Section III.
Footnote 15: Footnote 17:
- Since we’re in the realms of Sci-Fi, and operations on the cerebrum are usually undertaken using only local anaesthetic, might we not imagine that Prince remains conscious throughout?
- Would this strengthen the intuition?
- Of course, Prince would not see or hear – and therefore not really know – what has been going on in the operation – but would remain fully conscious throughout, and therefore would not be so easily persuaded that he is not who he thinks he is when the lights come on in Cobbler’s body.
Footnote 18: See the earlier footnote.
Footnote 21:
- It’s a bit quick, and Olson will attack it in Section III.
- So, it may not be the best effort for the PV.
Footnote 23:
- These will include non-branching conditions, the logic of which prohibit identity-preservation.
- Modal considerations along these lines make some insist on some physical continuity as well.
Footnote 26:
- OK – but it has received more attention because it is the stronger intuition - we're certain that we'd go with our cerebrum.
- However, we’re less certain that we’d cease to exist as Brainless – especially were it to come to being switched off.
- Olson also says that we could argue for the PV based on the intuition that Cobbler does not survive as Brainy: but this is even less secure – see "Williams (Bernard) - The Self and the Future", though this uses a BST rather than a cerebrum transplant.
Footnote 40: There’s lots that could be said here, but I’ve covered it – or will have soon – in my various brain-related Notes:- Footnote 46:
- I had added “and the corpus callosum is cut”, not in Olson’s text, but this is not necessary.
- It does appear in examples where – it is claimed – fission can be achieved by having two persons resident in the same skull without the need for practically unachievable transplants.
- This relies on equipollency considerations as in Olson’s TE.
- See Commissurotomy.
Footnote 50:
- I agree – in this case.
- However, we have to keep our TEs a little under control – as we’re dealing with our identity – what we are – not identity and persistence in general.
- When tinkering with the case, we have to ensure that the individual(s) under consideration remains one of us.
Footnote 51: Most likely, as he’s referring to the first edition, Chapter 7 ("Noonan (Harold) - The Reduplication Problem").
Footnote 52: This is based on the equipollency supposition.
Footnote 54:
Text Colour Conventions (see disclaimer)
- Blue: Text by me; © Theo Todman, 2026
- Mauve: Text by correspondent(s) or other author(s); © the author(s)