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Personal Identity

Fission

(Text as at 18/12/2010 19:58:05)

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


The paradigm case of Fission is of two half-brain1 transplants2. It is difficult to consider these cases without slipping into the “psychological view3”. Each hemisphere seems to preserve what matters4 to the fissioned individual, and a perdurance5 account can maintain identity6 after fission. An alternative account is to claim that the two half-brains always were separate persons (and Puccetti has maintained that they are separate persons, in all of us, even prior to the commissurotomy7 in this thought-experiment8), in a way slightly different from the usual Lewis9 view of non-identical spatially-coincident10 individuals11 (because the hemispheres aren’t spatially coincident, though the shared body12 is).

We need to consider how the original person13 was unified14. We can press the realism of the thought-experiment by asking how important are the spinal chord and PNS generally to the psychological integrity of the human organism15? The case of dicephalus16 twins may be relevant – where the functions of walking and even typing seem to be carried out perfectly adequately despite the coordinated limbs being controlled by different brains.

We also need to consider whether the two half-brains continue to constitute a single scattered17 person, just parked in separate bodies. A single embodiment is important because it ensures synchronisation of experience, and external communication between the hemispheres (in the absence of the usual internal communication across the corpus callosum). Presumably, this could be achieved in other ways. We can imagine a BIV18 linked by radio transmitters/receivers to a remote body – the brain is part of the body – so a single physical thing can be spatially discontinuous. Why, if A fissions into B and C, can’t we consider B & C to be parts of the same person? They could fight / argue … but so can someone in two minds about things. What if one killed the other? They would have different perceptual experiences, but so (presumably) does a chameleon, with its eyes pointing in different directions (and sheep and other herbivores, and fish, with eyes on the sides of their heads). I need to consider in detail what is supposed to be going on in fission – ie. press the thought experiment: there needs to be segregation / redundancy prior to separation – this can happen over time (or we would have plain duplication19). At some point the person will split, with incommunicable consciousnesses20 (cf. Locke21’s day-person and night-person).



Printable Versions:



Table of the Previous 2 Versions of this Note:

Date Length Title
26/11/2007 23:25:26 2853 Fission
12/08/2007 10:17:46 2506 Fission



Note last updated Reading List for this Topic Parent Topic
18/12/2010 19:58:05 Fission Thought Experiments

Summary of Note Links from this Page

Body Brain Brains in Vats Coincidence Commissurotomy
Consciousness Dicephalus Duplication Individual Lewis
Locke Logic of Identity Organisms Perdurantism Person
Psychological View Scattered Objects Thought Experiments Transplants Unity of the Person
What Matters        

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




Summary of Note Links to this Page

Blackburn - Has Kant Refuted Parfit? Brain Criterion Cerebrum Clones Commissurotomy
Dicephalus Endurantism Fetuses Fusion Kurtz - Persistence (Introduction)
Narrative Identity Occasional Identity Olson - Immanent Causation and Life After Death Parfit Perdurantism
Psychological Continuity - Forward Psychological Criterion Reduplication Objections Replication Research - Proposal
Teletransportation Thesis - Chapter 10 (Thought Experiments) Thesis - Current Stance Thesis - Outline Time, 2
Twinning Unity of the Person, 2 Zygote    

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




Authors, Books & Papers Citing this Note

Author Title Medium Extra Links Read?
Anscombe (G.E.M.) Were You a Zygote? Paper High Quality Abstract 2 Yes
Baker (Lynne Rudder) When Do Persons Begin and End? Paper High Quality Abstract   Yes
Blackburn (Simon) Has Kant Refuted Parfit? Paper Medium Quality Abstract    
Campbell (Scott) Persons and Substances Paper Medium Quality Abstract    
Cerullo (Michael A.) Uploading and Branching Identity Paper Medium Quality Abstract    
Dennett (Daniel) Where Am I? Paper High Quality Abstract   Yes
Ehring (Douglas) Personal Identity and Time Travel Paper Medium Quality Abstract   Yes
Kurtz (Roxanne) Introduction to Persistence: What’s the Problem? Paper High Quality Abstract   Yes
Lewis (David) On the Plurality of Worlds (Selections) Paper High Quality Abstract   Yes
Liao (S. Matthew) The Organism View Defended Paper Medium Quality Abstract   Yes
Olson (Eric) Animalism and the Remnant-Person Problem Paper Medium Quality Abstract 2 Yes
Olson (Eric) Immanent Causation and Life After Death Paper High Quality Abstract   Yes
Olson (Eric) Psychology and Personal Identity Paper High Quality Abstract   Yes
Shoemaker (David) Personal Identity and Immortality Paper High Quality Abstract 2, 3 Yes
Smith (Barry C.), Broks (Paul), Kennedy (A.L.) & Evans (Jules) What Does It Mean to Be Me? Paper High Quality Abstract   Yes
Todman (Theo) Thesis - Brain Criterion Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Cerebrum Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Clones Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Commissurotomy Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Current Position Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Dicephalus Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Endurantism Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Fetuses Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Fission Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Fusion Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Narrative Identity Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Occasional Identity Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Parfit Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Perdurantism Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Psychological Continuity - Forward Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Psychological Criterion Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Reduplication Objections Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Replication Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Teletransportation Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Time Paper Medium Quality Abstract 2 Yes
Todman (Theo) Thesis - Twinning Paper Medium Quality Abstract   Yes
Todman (Theo) Thesis - Unity of the Person Paper Medium Quality Abstract 2 Yes
Todman (Theo) Thesis - Zygote Paper Medium Quality Abstract   Yes
Wilson (Jack) Beyond Horses and Oak Trees: A New Theory of Individuation for Living Entities Paper High Quality Abstract   Yes



References & Reading List

Author Title Medium Source Read?
Anderson (Robert M.) & Gonsalves (Joseph F.) Sensory Suppression and the Unity of Consciousness Paper - By Subtopic Behavioral and Brain Sciences, 4: 99-100, 1981 No
Baars (Bernard), Banks (William) & Newman (James) Essential Sources in the Scientific Study of Consciousness Book - By Subtopic (via Paper By Subtopic) Medium Quality Abstract Baars (Bernard), Banks (William) & Newman (James) - Essential Sources in the Scientific Study of Consciousness 1%
Barilan (Y. Michael) One or Two: An Examination of the Recent Case of the Conjoined Twins from Malta Paper - By Subtopic Medium Quality Abstract Journal of Medicine and Philosophy, Feb. 2003, 28.1, pp. 27-44 No
Belzer (Marvin) Parfit and Lewis on Survival of Fission and What Matters in Survival: Why Parfit won the Debate Paper - By Subtopic 2002, Draft. Personal Website. No
Bogen (James) Further discussion on split-brains and hemispheric capabilities Paper - By Subtopic British Journal for the Philosophy of Science, Vol. 28, No. 3, Sep., 1977, pp. 281-286 No
Bogen (Joseph E.) Mental Numerosity: Is One Head Better Than Two? Paper - By Subtopic Behavioral and Brain Sciences, 4: 100-101, 1981 No
Bradshaw (John L.) In Two Minds Paper - By Subtopic Behavioral and Brain Sciences, 4: 101-102, 1981 No
Braude (Stephen) Multiple Personality and the Structure of the Self Paper - By Subtopic Low Quality Abstract Kolak & Martin - Self and Identity: Contemporary Philosophical Issues No
Brown (Jason) Structural Levels and Mental Unity Paper - By Subtopic Behavioral and Brain Sciences, 4: 102-103, 1981 No
Brown (M.T.) Multiple Personality and Personal Identity Paper - By Subtopic Medium Quality Abstract Philosophical Psychology, Volume 14, Number 4, 1 December 2001, pp. 435-447(13). No
Brueckner (Anthony) Branching in the psychological approach to personal identity Paper - By Subtopic Low Quality Abstract Analysis 65, October 2005, pp. 294-301(8) No
Burke (Michael) Spatial Analogues of 'Annihilation and Re-creation' Paper - By Subtopic Medium Quality Abstract Analysis 45, 1985, 24-29 No
Churchland (Patricia) How Many Angels … ? Paper - By Subtopic Behavioral and Brain Sciences, 4: 103-104, 1981 No
Cockburn (David), Ed. Human Beings Book - By Subtopic (via Paper By Subtopic) Low Quality Abstract Cockburn (David), Ed. - Human Beings 11%
Damasio (Antonio), Ed. The 'Scientific American' Book of the Brain: The Best Writing on Consciousness Book - By Subtopic (via Paper By Subtopic) Damasio (Antonio), Ed. - The 'Scientific American' Book of the Brain: The Best Writing on Consciousness No
Davidson (Richard) Cognitive Processing Is Not Equivalent To Conscious Processing Paper - By Subtopic Behavioral and Brain Sciences, 4: 104-105, 1981 No
Gallois (Andre) Counting Amoebas Paper - By Subtopic Low Quality Abstract Gallois - Occasions of Identity, 1998, Chapter 4 No
Gallois (Andre) Occasions of Identity : a Study in the Metaphysics of Persistence, Change, and Sameness Book - By Subtopic (via Paper By Subtopic) Low Quality Abstract Gallois (Andre) - Occasions of Identity : a Study in the Metaphysics of Persistence, Change, and Sameness No
Garrett (Brian) A Further Reply to Noonan Paper - By Subtopic Analysis 47, 1987, pp. 204-207 No
Garrett (Brian) Fission Paper - By Subtopic Medium Quality Abstract Garrett - Personal Identity and Self-consciousness, 1998, Chapter 4 Yes
Garrett (Brian) Johnston on Fission Paper - By Subtopic Low Quality Abstract Sorites 15, December 2004: 87-93 No
Garrett (Brian) Personal Identity and Self-consciousness Book - By Subtopic (via Paper By Subtopic) Medium Quality Abstract Garrett (Brian) - Personal Identity and Self-consciousness Yes
Gazzaniga (Michael S.) The Split Brain Revisited Paper - By Subtopic Damasio - The "Scientific American" Book of the Brain: The Best Writing on Consciousness No
Geschwind (Norman) The Perverseness of the Right Hemisphere Paper - By Subtopic Behavioral and Brain Sciences, 4: 106-107, 1981 No
Gillett (Grant) Brain Bisection and Personal Identity Paper - By Subtopic Low Quality Abstract Mind, New Series, Vol. 95, No. 378 (Apr., 1986), pp. 224-229 No
Glover (Jonathan) I: Philosophy and Psychology of Personal Identity Book - By Subtopic (via Paper By Subtopic) Glover (Jonathan) - I: Philosophy and Psychology of Personal Identity No
Glover (Jonathan) Split Brains Paper - By Subtopic Glover - I: Philosophy and Psychology of Personal Identity No
Green (Michael) May We Forget Our Minds For a Moment? Paper - By Subtopic Behavioral and Brain Sciences, 4: 107-108, 1981 No
Hawley (Katherine) Fission, Fusion and Intrinsic Facts Paper - By Subtopic Medium Quality Abstract Philosophy and Phenomenological Research (forthcoming, issue dated November 2005) Yes
Hershenov (David) & Koch-Hershenov (Rose J.) Fission and Confusion Paper - By Subtopic Medium Quality Abstract Christian Bioethics, 12:237–254, 2006 No
Johnston (Mark) Fission and the Facts Paper - By Subtopic Medium Quality Abstract Philosophical Perspectives 3: 369-97 31%
Joynt (Robert J.) Are Two Heads Better Than One? Paper - By Subtopic Behavioral and Brain Sciences, 4: 108-109, 1981 No
Kolak (Daniel) & Martin (Raymond), Eds. Self and Identity: Contemporary Philosophical Issues Book - By Subtopic (via Paper By Subtopic) Medium Quality Abstract Kolak (Daniel) & Martin (Raymond), Eds. - Self and Identity: Contemporary Philosophical Issues No
LeDoux (Joseph E.) & Gazzaniga (Michael S.) The Brain and the Split Brain: A Duel With Duality As a Model of Mind Paper - By Subtopic Behavioral and Brain Sciences, 4: 109-111, 1981 No
Marks (Charles) Mental Duality: An Unmade Case Paper - By Subtopic Behavioral and Brain Sciences, 4: 111-112, 1981 No
Martin (Raymond) Fission Rejuvenated Paper - By Subtopic Martin & Barresi - Personal Identity, Chapter 8 No
Martin (Raymond) & Barresi (John), Eds. Personal Identity Book - By Subtopic (via Paper By Subtopic) Medium Quality Abstract Martin (Raymond) & Barresi (John), Eds. - Personal Identity 20%
Martin (Raymond), Barresi (John) & Giovannelli (Alessandro) Fission Examples in 18th and Early 19th century Personal Identity Debate Paper - By Subtopic Medium Quality Abstract History of Philosophy Quarterly, 15, 1998, pp. 323-348 No
Matthews (Gareth B.) Surviving As Paper - By Subtopic Low Quality Abstract Analysis 38, 1977, pp. 53-58 No
Mills (Eugene) Dividing Without Reducing: Bodily Fission and Personal Identity Paper - By Subtopic Medium Quality Abstract Mind 102.405, Jan. 1993, pp. 37-51 No
Moyer (Mark) A Survival Guide to Fission Paper - By Subtopic Medium Quality Abstract Philosophical Studies, Vol. 141, No. 3 (Dec., 2008), pp. 299-322 5%
Munzer (Stephen R.) Transplantation, Chemical Inheritance, and the Identity of Organs Paper - By Subtopic Medium Quality Abstract British Journal for the Philosophy of Science, Vol. 45, No. 2, Jun., 1994, pp. 555-570 No
Nagel (Thomas) Brain Bisection and the Unity of Consciousness Paper - By Subtopic High Quality Abstract Nagel (Thomas) - Mortal Questions Yes
Nagel (Thomas) Mortal Questions Book - By Subtopic (via Paper By Subtopic) Low Quality Abstract Nagel (Thomas) - Mortal Questions Yes
Noonan (Harold) Personal Identity Book - By Subtopic (via Paper By Subtopic) Low Quality Abstract Noonan (Harold) - Personal Identity Yes
Noonan (Harold) The Reduplication Problem Paper - By Subtopic Low Quality Abstract Noonan - Personal Identity, 2003, Chapter 7 Yes
Noonan (Harold) Williams on 'The Self and the Future' Paper - By Subtopic Analysis, vol. 42, 1982, pp. 158-163 No
Oderberg (David) Fission, Intermittence and the Primitiveness of Identity Paper - By Subtopic Low Quality Abstract Oderberg - The Metaphysics of Identity Over Time, 1993, Chapter 7 No
Oderberg (David) The Metaphysical Status of the Embryo: Some Arguments Revisited Paper - By Subtopic Low Quality Abstract Journal of Applied Philosophy 25 (2008): 263-76 12%
Oderberg (David) The Metaphysics of Identity Over Time Book - By Subtopic (via Paper By Subtopic) Low Quality Abstract Oderberg (David) - The Metaphysics of Identity Over Time 4%
Oderberg (David) The Origination of a Human Being - Rejoinder to Persson Paper - By Subtopic Low Quality Abstract Unpublished: obtained from Oderberg's website No
Ord (Toby) Implications of fission, fusion and teletransportation to a view of personal identity through psychological continuity Paper - By Subtopic Medium Quality Abstract Website 20%
Perry (John) Can the Self Divide? Paper - By Subtopic Low Quality Abstract Perry - Identity, Personal Identity and the Self, 2002, Chapter 3 No
Perry (John) Identity, Personal Identity and the Self Book - By Subtopic (via Paper By Subtopic) Low Quality Abstract Perry (John) - Identity, Personal Identity and the Self 4%
Prior (Arthur N.) Opposite Number Paper - By Subtopic Low Quality Abstract Review of Metaphysics, Vol. 11, No. 2 (Dec., 1957), pp. 196-201 No
Puccetti (Roland) Mind with a Double Brain Paper - By Subtopic Low Quality Abstract British Journal for the Philosophy of Science, Vol. 44, No. 4, Dec., 1993, pp. 675-691 No
Puccetti (Roland) Multiple Identity Paper - By Subtopic Medium Quality Abstract Pacific Philosophical Quarterly, 54.3, 1973, 203-215 No
Puccetti (Roland) The Case For Mental Duality: Author's Responses + References Paper - By Subtopic Behavioral and Brain Sciences, 4: 116-123, 1981 No
Puccetti (Roland) The Case For Mental Duality: Evidence From Split-Brain Data and Other Considerations Paper - By Subtopic Behavioral and Brain Sciences, 4: 93-99, 1981 No
Puccetti (Roland) The Mute Self: A Reaction to Dewitt's Alternative Account of the Split-Brain Data Paper - By Subtopic Medium Quality Abstract British Journal for the Philosophy of Science, Vol. 27, No. 1, Mar., 1976, pp. 65-73 No
Puccetti (Roland) Two Brains, Two Minds? Wigan's Theory of Mental Duality Paper - By Subtopic Medium Quality Abstract Kolak & Martin - Self and Identity: Contemporary Philosophical Issues No
Robinson (Daniel) What Sort of Persons Are Hemispheres? Another Look at 'Split-Brain' Man Paper - By Subtopic Medium Quality Abstract British Journal for the Philosophy of Science, Vol. 27, No. 1, Mar., 1976, pp. 73-78 No
Robinson (Denis) Neurometaphorology: The New Faculty Psychology Paper - By Subtopic Behavioral and Brain Sciences, 4: 112-113, 1981 No
Rovane (Carol) Branching Self-Consciousness Paper - By Subtopic Medium Quality Abstract Philosophical Review 99.3, July 1990, pp. 355-395 No
Seibt (Johanna) Fission, Sameness, and Survival: Parfit’s Branch Line Argument Revisited Paper - By Subtopic Medium Quality Abstract Metaphysica 1.2 (2000), pp. 95-134 No
Shoemaker (Sydney) Brown-Brownson Revisited Paper - By Subtopic Low Quality Abstract Monist, Oct2004, Vol. 87 Issue 4, p573-593, 21p; No
Sperry (R.W.) Hemisphere Deconnection and the Unity in Conscious Awareness Paper - By Subtopic Medium Quality Abstract Baars, Banks & Newman - Essential Sources in the Scientific Study of Consciousness 11%
Sperry (R.W.) Some Effects of Disconnecting the Cerebral Hemispheres Paper - By Subtopic Low Quality Abstract Science, New Series, Vol. 217, No. 4566 (Sep. 24, 1982), pp. 1223-1226 33%
Thornton (Mark) Double Brain, Double Person? Paper - By Subtopic British Journal for the Philosophy of Science, Vol. 45, No. 2, Jun., 1994, pp. 761-763 No
Todman (Theo) Thesis - Fission Paper - By Subtopic Medium Quality Abstract   Yes
Unger (Peter) Fission and the Focus of One's Life Paper - By Subtopic Low Quality Abstract Unger - Identity, Consciousness and Value, Chapter 8 Yes
Unger (Peter) Fission and the Focus of One's Life (Excerpt) Paper - By Subtopic Low Quality Abstract Martin & Barresi - Personal Identity, Chapter 6 Yes
Unger (Peter) Identity, Consciousness and Value Book - By Subtopic (via Paper By Subtopic) Medium Quality Abstract Unger (Peter) - Identity, Consciousness and Value Yes
Valberg (J.J.) Dream, Death, and the Self Book - By Subtopic (via Paper By Subtopic) Medium Quality Abstract Valberg (J.J.) - Dream, Death, and the Self 1%
Valberg (J.J.) My Future: The Puzzle of Division Paper - By Subtopic Low Quality Abstract Valberg (J.J.) - Dream, Death, and the Self, 2007, Chapter 23 No
van Dyke (Christina) Human Identity, Immanent Causal Relations, and the Principle of Non-Repeatability: Thomas Aquinas on the Bodily Resurrection Paper - By Subtopic Low Quality Abstract Religious Studies, Vol. 43, No. 4 (Dec., 2007), pp. 373-394 No
Von Eckardt (Barbara) Puccetti's Mental-Duality Thesis: A Case Of Bad Arguments Paper - By Subtopic Behavioral and Brain Sciences, 4: 113-114, 1981 No
Wilkes (Kathleen) Being in Two Minds Paper - By Subtopic Low Quality Abstract Wilkes - Real People: Personal Identity Without Thought Experiments, Chapter 5 Yes
Wilkes (Kathleen) Fugues, Hypnosis, and Multiple Personality Paper - By Subtopic Low Quality Abstract Wilkes - Real People: Personal Identity Without Thought Experiments, Chapter 4 Yes
Wilkes (Kathleen) How Many Selves Make Me? Paper - By Subtopic Cockburn - Human Beings No
Wilkes (Kathleen) Real People: Personal Identity Without Thought Experiments Book - By Subtopic (via Paper By Subtopic) Medium Quality Abstract Wilkes (Kathleen) - Real People: Personal Identity Without Thought Experiments Yes
Wilkes (Kathleen) Unfused Homunculi Paper - By Subtopic Behavioral and Brain Sciences, 4: 115-116, 1981 No
Wright (John) Personal Identity, Fission and Time Travel Paper - By Subtopic Medium Quality Abstract Philosophia (2006) 34: 129–142 67%
Zimmerman (Dean) & Gendler (Tamar Szabo), Eds. Monist Special Issue: Personal Identity Book - By Subtopic (via Paper By Subtopic) Zimmerman (Dean) & Gendler (Tamar Szabo), Eds. - Monist Special Issue: Personal Identity 3%



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