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Personal Identity

Occasional Identity

(Text as at 06/07/2023 00:43:12)

Plug Note¹

• Thesis Text:
  1. Occasional identity is a response to TEs such as the fission² of an amoeba into two qualitatively identical ones. We want to say that both are numerically identical to the parent, but the logic of identity³ forbids this unless we claim that the two daughters are numerically identical to one another, though even this seemingly-impossible claim has been supported: see "Miller (Kristie) - Travelling in Time: How to Wholly Exist in Two Places at the Same Time".
  2. So, the claim is that the amoebae were once identical (and co-incident: though not in the sense supposed by Constitution⁴ or Perdurance⁵ or co-location), but now are not.
  3. This makes numerical identity⁶ into a temporary (hence “occasional”) matter.
  4. It’s important not to confuse “temporary identity” with “temporal identity”. Maybe some philosophers – even if not confused – have been careless with their terminology. Some philosophers seem to use “temporal identity” for “diachronic identity” while others use it for “occasional identity”.
  5. My preferred answer to this TE is to appeal to perdurance⁷ – the daughters were always distinct, but just shared their pre-fission stages. There are other explanations.

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  Further Remarks:
  1. The orthodox approach to the Logic of Identity⁸ is to treat it as a necessary equivalence relation. I follow this approach.
  2. However, in response to various TEs⁹, deviant forms₁₀ of Identity have been devised, and some are still popular.
  3. However, the logic of identity¹¹ is so secure that it is sensible to look for other explanations of any TE that appears to bring it in doubt.
  4. I intend to cover this topic in Chapter 4¹² along with the other deviant approaches to Identity.

References

• Relevant Works cited above:
  1. "Miller (Kristie) - Travelling in Time: How to Wholly Exist in Two Places at the Same Time", 2006, Internal PDF Link, Read = 29%
• For a page of Links¹³ to this Note, Click here.
• Works on this topic that I’ve actually read¹⁴, include the following:-
  • General:
    1. "Anscombe (G.E.M.) - Were You a Zygote?", 1982
    2. "Baker (Lynne Rudder) - Precis of 'Persons & Bodies: A Constitution View'", 2001, Write-Up Note¹⁵, Annotations, Internal PDF Link, Footnote₁₆
    3. "Baker (Lynne Rudder) - The Very Idea of Constitution", 2000, Write-Up Note¹⁷, Internal PDF Link, Footnote₁₈
    4. "Sider (Ted) - In Favour of Four-Dimensionalism, Part 2: The Best Unified Theory of the Paradoxes of Coincidence", 2003, Annotations
• A further reading list might start with:-
  • General:
    1. "Akiba (Ken) - Identity Is Simple", 2000, Internal PDF Link, Read = 20%
    2. "Gallois (Andre) - Identity Over Time", 2005-11, External Link, Internal PDF Link, Read = 4%
    3. "Gallois (Andre) - Langford and Ramachandran on Occasional Identities", 2001, Internal PDF Link
    4. "Gallois (Andre) - Occasional Identity", 1990, Internal PDF Link, Read = 6%
    5. "Gallois (Andre) - Occasions of Identity : a Study in the Metaphysics of Persistence, Change, and Sameness", 2003, Book
    6. "Langford (Simon) & Ramachandran (Murali) - Rigidity, Occasional Identity and Leibniz's Law", 2000, Internal PDF Link
    7. "Miller (Kristie) - Travelling in Time: How to Wholly Exist in Two Places at the Same Time", 2006, Internal PDF Link, Read = 29%
    8. "Sider (Ted) - Replies to Gallois, Hirsch and Markosian", 2004, External Link, Read = 17%
    9. "Sider (Ted) - Review of André Gallois, Occasions of Identity", 2001, External Link, Internal PDF Link, Read = 33%, Footnote₁₉

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• For a list of Works that have been considered, but have missed the cut for inclusion in this Section of my Thesis, see the following:-
  1. Read: No items to list.
  2. Further Reading: No items to list.
• This is mostly a place-holder²⁰.

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In-Page Footnotes:

Footnote 10:

• I’m not sure if this is the correct terminology.

Footnotes 16, 18:

• Baker claims that the Constitution View solves problems that “temporal identity”, etc, are supposed to address.

Footnote 19:

• Read and analyse this first – it may not be worth bothering with the book, unless it sheds light on the topic as a whole.

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Table of the Previous 8 Versions of this Note:

Date	Length	Title
20/09/2022 11:24:00	3703	Occasional Identity
01/05/2022 18:20:10	3322	Occasional Identity
15/02/2021 13:40:48	3144	Occasional Identity
05/12/2019 10:59:31	2789	Occasional Identity
03/09/2018 19:49:26	4874	Occasional Identity
06/07/2015 18:30:14	2239	Occasional Identity
26/11/2007 23:25:26	84	Occasional Identity
12/08/2007 10:17:46	80	Occasional Identity

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Note last updated	Reading List for this Topic	Parent Topic
06/07/2023 00:43:12	Occasional Identity	Logic of Identity

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Summary of Notes Referenced by This Note

Awaiting Attention (Personal Identity)	Baker - Persons and Bodies - Precis	Baker - The Very Idea of Constitution	Constitution	Constitution View
Fission	Logic of Identity	Note Links Explanation	Numerical Identity	Perdurantism
Plug Note Apologia	Thesis - Chapter 04 (Basic Metaphysical Issues)	Thought Experiments	Works Read - Explanation

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

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Summary of Notes Citing This Note

Baker - The Coherence Of the Idea of Material Constitution	Baker - The Very Idea of Constitution	Logic of Identity	PID Note, Book & Paper Usage, 2, 3	Thesis - Chapter 04 (Basic Metaphysical Issues), 2, 3, 4, 5
Thesis - Current Stance	Thesis - Personal Identity, 2	Website Generator Documentation - Functors, 2, 3, 4, 5, 6

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?
Akiba (Ken)	Identity Is Simple	Paper	2
Anscombe (G.E.M.)	Were You a Zygote?	Paper		Yes
Baker (Lynne Rudder)	Precis of 'Persons & Bodies: A Constitution View'	Paper		Yes
Baker (Lynne Rudder)	The Coherence Of the Idea of Material Constitution	Paper		Yes
Baker (Lynne Rudder)	The Very Idea of Constitution	Paper		Yes
Baxter (Donald L.M.)	Temporary and Contingent Instantiation as Partial Identity	Paper
Gallois (Andre)	Identity Over Time	Paper
Gallois (Andre)	Langford and Ramachandran on Occasional Identities	Paper
Gallois (Andre)	Occasional Identity	Paper
Gallois (Andre)	Occasions of Identity : a Study in the Metaphysics of Persistence, Change, and Sameness	Book
Langford (Simon) & Ramachandran (Murali)	Rigidity, Occasional Identity and Leibniz's Law	Paper	2, 3, 4, 5
Olson (Eric)	What Are We? Contents + References	Paper		Yes
Sider (Ted)	In Favour of Four-Dimensionalism, Part 2: The Best Unified Theory of the Paradoxes of Coincidence	Paper	2	Yes
Sider (Ted)	Replies to Gallois, Hirsch and Markosian	Paper
Todman (Theo)	Thesis - Chapter 04 (Basic Metaphysical Issues)	Paper	2, 3, 4, 5	Yes
Todman (Theo)	Thesis - Current Position	Paper		Yes
Todman (Theo)	Thesis - Logic of Identity	Paper		Yes
Todman (Theo)	Thesis - Personal Identity	Paper	2

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References & Reading List

Author	Title	Medium	Source	Read?
Akiba (Ken)	Identity Is Simple	Paper - Cited	American Philosophical Quarterly, Vol. 37, No. 4 (Oct., 2000), pp. 389-404	20%
Anscombe (G.E.M.)	Were You a Zygote?	Paper - Cited	Anscombe (G.E.M) - Human Life, Action and Ethics	Yes
Anscombe (G.E.M.), Geach (Mary), Gormally (Luke), Eds.	Human Life, Action and Ethics	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	10%
Baker (Lynne Rudder)	Persons and Bodies: A Constitution View	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	Yes
Baker (Lynne Rudder)	Precis of 'Persons & Bodies: A Constitution View'	Paper - Cited	Field Guide to the Philosophy of Mind, 2001, e-Symposium on "Persons & Bodies: A Constitution View"	Yes
Baker (Lynne Rudder)	The Very Idea of Constitution	Paper - Cited	Baker (Lynne) - Persons and Bodies, Chapter 2, pp. 27-58	Yes
Baker (Lynne Rudder), Etc.	E-Symposium on 'Persons & Bodies: A Constitution View'	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	Yes
Gallois (Andre)	Extending the Occasional Identity Thesis	Paper - By Subtopic	Gallois - Occasions of Identity, 1998, Chapter 5	No
Gallois (Andre)	Identity Over Time	Paper - Cited	Stanford Encyclopaedia of Philosophy, 2005-11	4%
Gallois (Andre)	Langford and Ramachandran on Occasional Identities	Paper - Cited	Philosophical Quarterly, 2001, Vol. 51 Issue 204, p378, 8p	No
Gallois (Andre)	Occasional Identities: A Preliminary Account	Paper - By Subtopic	Gallois - Occasions of Identity, 1998, Chapter 3	No
Gallois (Andre)	Occasional Identity	Paper - Cited	Philosophical Studies Vol. 58.3: March 1990, pp. 203-224	6%
Gallois (Andre)	Occasions of Identity : a Study in the Metaphysics of Persistence, Change, and Sameness	Book - Cited	Gallois (Andre) - Occasions of Identity : a Study in the Metaphysics of Persistence, Change, and Sameness	No
Gallois (Andre)	Occasions of Identity: Introduction	Paper - By Subtopic	Gallois - Occasions of Identity, 1998, Introduction	No
Gallois (Andre)	Perry and Myro on Occasional Identities	Paper - By Subtopic	Gallois - Occasions of Identity, 1998, Chapter 7	No
Gallois (Andre)	Solutions to the Puzzle Cases	Paper - By Subtopic	Gallois - Occasions of Identity, 1998, Chapter 2	No
Langford (Simon) & Ramachandran (Murali)	Rigidity, Occasional Identity and Leibniz's Law	Paper - Cited	Philosophical Quarterly, 2000, Vol. 50 Issue 201, p518, 9p	No
Miller (Kristie)	Travelling in Time: How to Wholly Exist in Two Places at the Same Time	Paper - Cited	Canadian Journal of Philosophy, Vol. 36, No. 3 (Sep., 2006), pp. 309-334	29%
Sider (Ted)	Four-dimensionalism: An Ontology of Persistence and Time	Book - Cited (via Paper Cited)	Bibliographical details to be supplied	12%
Sider (Ted)	In Favour of Four-Dimensionalism, Part 2: The Best Unified Theory of the Paradoxes of Coincidence	Paper - Cited	Sider - Four-dimensionalism, Chapter 5	Yes
Sider (Ted)	Replies to Gallois, Hirsch and Markosian	Paper - Cited	Philosophy and Phenomenological Research LXVII, No. 3, May 2004, pp. 674-687	17%
Sider (Ted)	Review of André Gallois, Occasions of Identity	Paper - By Subtopic	British Journal for the Philosophy of Science 52 (2001): 401–5	33%
Todman (Theo)	Thesis - Occasional Identity	Paper - By Subtopic		Yes

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1. Blue: Text by me; © Theo Todman, 2025

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