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Personal Identity

Brain Criterion

(Text as at 04/12/2019 23:36:58)

(For earlier versions of this Note, see the table at the end)

Plug Note¹

• There will naturally be some overlap on this topic with the topics of
  → Brains² and
  → Criteria of Identity³.
• The question is whether the brain is the be-all and end-all of the matter of personal identity for human persons⁴.
• This view seems to be presupposed by those ethicists who espouse the (whole or part) brain death⁵ criterion for death⁶. There will be some overlap between this note and that on brain death.
• It is acknowledged by most that – conceptually at least – there can be persons⁷ that are not humans (ie. not members of the species homo sapiens) – whether these persons be non-human animals, computers, God, angels, aliens or whatever. Non-animals presumably have no brains, though aliens presumably have a brain-analogue, so brains cannot be identity-criteria for personhood as such (indeed, we might argue that there are no criteria for persons as such₈). But for animal-persons (human or otherwise), the brain seems to occupy a central place, both as the seat of psychology (in the absence of an immaterial soul⁹) and as the regulator of the body.
• So, the story would go, X is the same person as Y iff₁₀ X has the same brain as Y.
• The trouble is – even if this claim is along the right lines – we can press matters further, and ask whether the whole brain is strictly necessary. If what impresses us is a brain-based psychological view, when what we imagine is “really the minimal me” is the pair of psychology-bearing cerebral hemispheres, then we might imagine (as some philosophers have) a case of fission¹¹, where – after equalising the hemispheres in psychological potency, we transplant¹² one into another body lacking both hemispheres. Or, without needing anything so radical, we sever the corpus callosum in a commissurotomy¹³, thereby (on this view) creating two persons in one body.
• However, if we are animalists¹⁴,¹⁵ wondering what the “minimal animal” is, and it’s the command-and-control functions of the brain that impress us, then the paring-down process might₁₆ be able to do without the cerebral hemispheres (or at least the psychology-bearing parts) altogether. So, brain-based views from different perspectives might come to different conclusions about the importance of the cerebral hemispheres – one view might make them essential, the other irrelevant to questions of identity (if not to “what matters¹⁷”). It is an empirical question whether the brain-stem can be divided, and hence whether a brain-based animalist approach is also subject to worries₁₈ about fission.
• Anyway, the appropriateness of the Brain criterion of personal identity depends on what we are¹⁹– in particular whether we are (most fundamentally, or in the sense of numerical identity²⁰, which is not the same thing) human animals or persons constituted by²¹ them (or various other things).
• Only if₂₂ we believe that we are (identical to) brains²³ will we adopt the brain criterion.
• For a page of Links²⁴ to this Note, Click here. Slim pickings.
• Works on this topic that I’ve actually read²⁵ include the following:-
  1. "Garrett (Brian) - Criteria of Personal Identity", Garrett
  2. "Gert (Bernard), Lizza (John), Youngner (Stuart) & Chiong (Winston) - Matters of 'Life' and 'Death'", Gert, Etc.
  3. "Johnston (Mark) - Human Beings", Johnston₂₆
  4. "Manninen (Tuomas) - Review of Alva Noe's 'Out of Our Heads: Why You Are Not Your Brain'", Manninen
  5. "Noonan (Harold) - An Initial Survey", Noonan
  6. "Parfit (Derek) - Nagel's Brain", Parfit
  7. "Snowdon (Paul) - The Self and Personal Identity", Snowdon
  8. "Thomas (Janice L.) - The bodily criterion", Thomas
• A reading list (where not covered elsewhere) might start with:-
  1. "Hershenov (David) - Who Doesn't Have a Problem of Too Many Thinkers?", Hershenov
  2. "Noe (Alva) - Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness", Noe
  3. "Olson (Eric) - What Are We? Brains", Olson
  4. "Parfit (Derek) - Persons, Bodies, and Human Beings", Parfit
• This is mostly a place-holder²⁷.

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In-Page Footnotes:

Footnote 8:

• Hasn’t someone said this? Who? Wiggins?
• This is not to be confused with there being no criteria for identity – ie. for the relation itself – which is due to Merricks (eg. in "Merricks (Trenton) - There Are No Criteria For Identity Over Time").

Footnote 10:

• And, of course, “X and Y are both persons”, to cover the case where the brain is insufficient to support the property of personhood.

Footnote 16:

• Much of this discussion has empirical aspects to it, and depends on the capabilities of real brains – though we might get into the choppy waters of more intricate TEs, and wonder what might be the case if the biology went differently – but then we would most likely not be talking about our identity criteria, but of some other being.

Footnote 18:

• These worries about fission are essentially set to rest by adopting a perdurantist account of persistence.
• But, some consider the costs (mainly semantic, I think) of adopting this approach are too great.

Footnote 22:

• But see the Note on Johnston below!

Footnote 26:

• Johnston thinks we are human beings, but – when push comes to shove – we would survive as brains, so the criteria of our identity are – for Johnston – brain based.

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Printable Versions:

• Follow (this link) for level 0 (with reading list), and
• Follow (this link) for level 0.

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Table of the Previous 4 Versions of this Note:

Date	Length	Title
14/03/2018 10:07:41	5786	Brain Criterion
03/02/2018 18:44:38	5454	Brain Criterion
14/07/2013 23:02:24	3802	Brain Criterion
25/05/2010 14:58:34	84	Brain Criterion

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Note last updated	Reading List for this Topic	Parent Topic
04/12/2019 23:36:58	Brain Criterion	Logic of Identity

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Summary of Note Links from this Page

Animalism	Animalists	Awaiting Attention (Personal Identity)	Brain	Brain Death
Brain Transplants	Commissurotomy	Constitution	Criteria of Identity	Death
Fission	Human Beings	Human Persons	Note Links Explanation	Numerical Identity
Perdurantism	Person	Plug Note Apologia	Souls	Thought Experiments
What are We?	What Matters	Wiggins	Works Read - Explanation

To access information, click on one of the links in the table above.

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Summary of Note Links to this Page

Brain

Brain Death

Mereology

Snowdon - The Self and Personal Identity

Thesis - Current Stance

To access information, click on one of the links in the table above.

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Authors, Books & Papers Citing this Note

Author	Title	Medium	Extra Links	Read?
Garrett (Brian)	Criteria of Personal Identity	Paper	2, 3	Yes
Gert (Bernard), Lizza (John), Youngner (Stuart) & Chiong (Winston)	Matters of 'Life' and 'Death'	Paper		Yes
Hershenov (David)	Who Doesn't Have a Problem of Too Many Thinkers?	Paper
Noonan (Harold)	An Initial Survey	Paper		Yes
Olson (Eric)	Animalism and the Remnant-Person Problem	Paper		Yes
Olson (Eric)	Psychology and Personal Identity	Paper		Yes
Olson (Eric)	Why We Need Not Accept the Psychological Approach	Paper		Yes
Parfit (Derek)	Persons, Bodies, and Human Beings	Paper
Potts (Michael)	A Requiem for Whole Brain Death: A Response to D. Alan Shewmon's ‘The Brain and Somatic Integration’	Paper
Snowdon (Paul)	Persons, Animals, Ourselves: Introduction	Paper		Yes
Snowdon (Paul)	The Self and Personal Identity	Paper		Yes
Thomas (Janice L.)	The bodily criterion	Paper	2, 3, 4	Yes
Todman (Theo)	Thesis - Brain	Paper		Yes
Todman (Theo)	Thesis - Brain Criterion	Paper		Yes
Todman (Theo)	Thesis - Brain Death	Paper		Yes
Todman (Theo)	Thesis - Current Position	Paper		Yes
Todman (Theo)	Thesis - Mereology	Paper		Yes

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References & Reading List

Author	Title	Medium	Source	Read?
Garrett (Brian)	Criteria of Personal Identity	Paper - Cited	Garrett - Personal Identity and Self-consciousness, 1998, Chapter 3	Yes
Garrett (Brian)	Personal Identity and Self-consciousness	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	Yes
Gert (Bernard), Lizza (John), Youngner (Stuart) & Chiong (Winston)	Matters of 'Life' and 'Death'	Paper - Cited	The Hastings Center Report, Vol. 36, No. 3 (May - Jun., 2006), pp. 4-6	Yes
Hershenov (David)	Who Doesn't Have a Problem of Too Many Thinkers?	Paper - Cited	American Philosophical Quarterly, 50:2, April 2013, 203-208	No
Johnston (Mark)	Human Beings	Paper - Cited	Journal of Philosophy, Volume 84, Issue 2 (Feb 1987), 59-83	Yes
Manninen (Tuomas)	Review of Alva Noe's 'Out of Our Heads: Why You Are Not Your Brain'	Paper - Cited	Metapsychology Online Reviews, Sep 15th 2009 (Volume 13, Issue 38)	Yes
Merricks (Trenton)	There Are No Criteria For Identity Over Time	Paper - Cited	Noûs, Vol. 32, No. 1 (Mar., 1998), pp. 106-124	No
Noe (Alva)	Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness	Book - Cited	Noe (Alva) - Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness	23%
Noonan (Harold)	An Initial Survey	Paper - Cited	Noonan - Personal Identity, 2003, Chapter 1	Yes
Noonan (Harold)	Personal Identity	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	Yes
Olson (Eric)	Psychology and Personal Identity	Paper - Referencing	The Human Animal, September 1999, Chapter 1, pp. 7-21	Yes
Olson (Eric)	The Human Animal - Personal Identity Without Psychology	Book - Referencing (via Paper Referencing)	Bibliographical details to be supplied	Yes
Olson (Eric)	What are We? A Study of Personal Ontology	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	57%
Olson (Eric)	What Are We? Brains	Paper - Cited	What Are We? A Study in Personal Ontology, Chapter 4 (November 2007: Oxford University Press.)	22%
Olson (Eric)	Why We Need Not Accept the Psychological Approach	Paper - Referencing	The Human Animal, September 1999, Chapter 3, pp. 42-72	Yes
Parfit (Derek)	Nagel's Brain	Paper - Cited	Parfit - Reasons and Persons, Appendix D	Yes
Parfit (Derek)	Persons, Bodies, and Human Beings	Paper - Cited	Sider (Ted), Hawthorne (John) & Zimmerman (Dean), Eds. - Contemporary Debates in Metaphysics	7%
Parfit (Derek)	Reasons and Persons	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	Yes
Shand (John)	Central Issues of Philosophy	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	34%
Sider (Ted), Hawthorne (John) & Zimmerman (Dean), Eds.	Contemporary Debates in Metaphysics	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	10%
Snowdon (Paul)	Persons, Animals, Ourselves	Book - Referencing (via Paper Referencing)	Bibliographical details to be supplied	21%
Snowdon (Paul)	Persons, Animals, Ourselves: Introduction	Paper - Referencing	Snowdon (Paul) - Persons, Animals, Ourselves - Introduction	Yes
Snowdon (Paul)	The Self and Personal Identity	Paper - Cited	Shand (John) - Central Issues of Philosophy, Chapter 9	Yes
Thomas (Janice L.)	Mind and Person in the Philosophy of Religion	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	Yes
Thomas (Janice L.)	The bodily criterion	Paper - Cited	Thomas (Janice L.) - Mind and Person in the Philosophy of Religion	Yes
Todman (Theo)	Thesis - Brain Criterion	Paper - By Subtopic		Yes

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