Theo Todman's Web Page - Notes Pages
Personal Identity
Similarity
(Text as at 06/07/2023 00:43:12)
Plug Note1
- Thesis Text:
- The logic of similarity, like the logic of identity2, is a prerequisite for understanding continuity3 and change4.
- It is important to distinguish identity from exact similarity, as in the case of "identical" twins" which are not identical in the strict logical sense.
- Some initial thoughts:-
- “Exact Similarity” is an equivalence relation in that it is reflexive, symmetric and transitive.
- “Similarity” is less obviously an equivalence relation – however it is defined – because the transitivity relation may be deemed to fail.
- “Identical twins” – despite the suggestion above – are not even “exactly similar” in the strict sense, as it’s only genetically that they are exactly similar. In principle, each set of chromosomes in either twin is exactly similar to any other. And, I suppose, we could say that as their genomes are abstract objects, they are numerically identical. But the bodies and minds of identical twins – while “similar”, barring accidents, are not “exactly similar”, other than immediately after birth (and then only if we’re lucky).
- “Exactly similar” individuals would seem to have all non-relational properties in common. To make the term useful in practical life, we might have to allow some latitude. If I want my television replaced by an “exactly similar” one, I want one that’s how the one I bought ought to have been without whatever defects are inducing me to return it. Nor may I care for trivial differences in weight, surface marks and the like.
- “Similarity” applies to particular properties of things (“wearing similar ties”) or to individuals in their entirety (as “identical twins”).
References
- Relevant Works cited above: No items to list.
- For a Page of Links5 to this Note, Click here. A huge list, so no possibility of an updating run, but very useful to cherry-pick from.
- Works on this topic that I’ve actually read6, include7 the following:-
- Aeon:
- "Suchow (Jordan) - Haven’t we met before? On doppelgängers and perception", 2018, External Link, Internal PDF Link
- General:
- "Hirsch (Eli) - A Sense of Unity", 1982
- "Hirsch (Eli) - Natural Kinds and Natural Units", 1982
- "Kagan (Shelly) - What matters (continued); The nature of death, Part I", 2007, External Link
- "Olson (Eric) - The Human Animal: Introduction", 1999
- "Parfit (Derek) - What We Believe Ourselves To Be", 1986, Write-Up Note8
- "Shoemaker (David) - Personal Identity and Immortality", 2009
- A further reading list might start with:-
- General:
- "Brennan (Andrew) - Similarity and Affordance", 1988
- "Deutsch (Harry) - Identity and General Similarity", 1998, Internal PDF Link
- "Fodor (Jerry) - Similarity", 1998, No Abstract
- "Gratton-Guiness (I.) - Structural Similarity or Structuralism? Comments on Priest's Analysis of the Paradoxes of Self-Reference", 1998
- "Heil (John) - Imperfect Similarity", 2003
- "Hirsch (Eli) - Projectibility and Strange Languages", 1993
- "Hirsch (Eli) - Similarity and Natural Properties", 1993
- "Koslicki (Kathrin) - Constitution and Similarity", 2004, External Link, Internal PDF Link, Read = 6%
- "Martin (C.B.) - Identity and Exact Similarity", 1958, Internal PDF Link
- "Maurin (Anna-Sofia) - Same But Different", 2005, Internal PDF Link
- "Morreau (Michael) - It Simply Does Not Add Up: Trouble With Overall Similarity", 2010, Internal PDF Link
- "Nerlich (G.C.) - Sameness, Difference and Continuity", 1958, Internal PDF Link
- "Shoemaker (Sydney) - Phenomenal Similarity", 2003, No Abstract
- "Taylor (Barry) - Transworld Similarity and Transworld Belief", 2004, No Abstract
- "Vander Laan (David) - Counterpossibles and Similarity", 2004, No Abstract
- 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:-
- Read: No items to list.
- Further Reading: No items to list.
- This is mostly a place-holder9.
In-Page Footnotes:
Footnote 7:
- Most of these references touch on the topic of Similarity somewhat tangentially.
Table of the Previous 10 Versions of this Note:
Summary of Notes Referenced by This Note
To access information, click on one of the links in the table above.
Summary of Notes Citing This Note
Duplication |
Personality |
PID Note, Book & Paper Usage, 2, 3, 4, 5, 6, 7 |
Psychological Continuity - Forward |
Teletransportation, 2 |
Thesis - Chapter 03 (What is a Person?) |
Thesis - Chapter 04 (Basic Metaphysical Issues), 2, 3, 4, 5 |
Thesis - Chapter 10 (Thought Experiments), 2, 3 |
Thesis - Current Stance |
Website Generator Documentation - Functors, 2, 3, 4, 5, 6 |
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? |
Baker (Lynne Rudder) |
N/A |
Author |
|
|
Brennan (Andrew) |
Similarity and Affordance |
Paper  |
|
|
Deutsch (Harry) |
Identity and General Similarity |
Paper  |
2, 3, 4, 5 |
|
Doyle (Robert O.) |
N/A |
Author  |
|
|
Hirsch (Eli) |
A Sense of Unity |
Paper  |
|
Yes |
Hirsch (Eli) |
Natural Kinds and Natural Units |
Paper  |
|
Yes |
Hirsch (Eli) |
Projectibility and Strange Languages |
Paper  |
2, 3, 4, 5 |
|
Hirsch (Eli) |
Similarity and Natural Properties |
Paper  |
|
|
Honderich (Ted) |
N/A |
Author  |
|
|
Kagan (Shelly) |
What matters (continued); The nature of death, Part I |
Paper  |
|
Yes |
Olson (Eric) |
The Human Animal: Introduction |
Paper  |
2 |
Yes |
Parfit (Derek) |
What We Believe Ourselves To Be |
Paper  |
|
Yes |
Shoemaker (David) |
Personal Identity and Ethics - Introduction |
Paper  |
|
Yes |
Shoemaker (David) |
Personal Identity and Immortality |
Paper  |
2, 3, 4, 5, 6 |
Yes |
Suchow (Jordan) |
Haven’t we met before? On doppelgängers and perception |
Paper  |
2, 3, 4, 5, 6 |
Yes |
Tammet (Daniel) |
N/A |
Author  |
2, 3 |
|
Todman (Theo) |
Thesis - Chapter 03 (What is a Person?) |
Paper  |
|
Yes |
Todman (Theo) |
Thesis - Chapter 04 (Basic Metaphysical Issues) |
Paper  |
2, 3, 4, 5 |
Yes |
Todman (Theo) |
Thesis - Chapter 10 (Thought Experiments) |
Paper  |
2, 3 |
Yes |
Todman (Theo) |
Thesis - Current Position |
Paper  |
|
Yes |
Todman (Theo) |
Thesis - Duplication |
Paper  |
|
Yes |
Todman (Theo) |
Thesis - Personality |
Paper  |
|
Yes |
Todman (Theo) |
Thesis - Psychological Continuity - Forward |
Paper  |
|
Yes |
Todman (Theo) |
Thesis - Teletransportation |
Paper  |
2 |
Yes |
References & Reading List
Author |
Title |
Medium |
Source |
Read? |
Barbour (Ian) |
Religion in an Age of Science |
Book - By Subtopic (via Paper By Subtopic) |
Barbour (Ian) - Religion in an Age of Science |
No |
Barbour (Ian) |
Similarities and Differences |
Paper - By Subtopic |
Barbour - Religion in an Age of Science, 1990 |
No |
Brennan (Andrew) |
Conditions of Identity |
Book - Cited (via Paper Cited)  |
Bibliographical details to be supplied |
0% |
Brennan (Andrew) |
Similarity and Affordance |
Paper - Cited  |
Brennan - Conditions of Identity, 1988, Chapter 7 |
No |
Churchland (Paul) |
Conceptual Similarity across Sensory and Neural Diversity: The Fodor-Lepore Challenge Answered |
Paper - By Subtopic  |
Churchland & Churchland - On the Contrary: Critical Essays, 1987 - 1997 |
No |
Churchland (Paul) & Churchland (Patricia) |
On the Contrary: Critical Essays, 1987 - 1997 |
Book - By Subtopic (via Paper By Subtopic) |
Churchland (Paul) & Churchland (Patricia) - On the Contrary: Critical Essays, 1987 - 1997 |
No |
Fodor (Jerry) |
Concepts - Where Cognitive Science Went Wrong |
Book - By Subtopic (via Paper By Subtopic)  |
Fodor (Jerry) - Concepts - Where Cognitive Science Went Wrong |
No |
Fodor (Jerry) |
Similarity |
Paper - By Subtopic |
Fodor - Concepts - Where Cognitive Science Went Wrong, Appendix 6A |
No |
Hains (Brigid) & Hains (Paul) |
Aeon: Q-S |
Book - Cited (via Paper Cited)  |
Bibliographical details to be supplied |
30% |
Heil (John) |
Imperfect Similarity |
Paper - By Subtopic  |
Heil - From an Ontological Point of View, 2003, Chapter 14 |
No |
Jackson (Frank) & Priest (Graham), Eds. |
Lewisian Themes: The Philosophy of David K. Lewis |
Book - By Subtopic (via Paper By Subtopic)  |
Jackson (Frank) & Priest (Graham), Eds. - Lewisian Themes: The Philosophy of David K. Lewis |
5% |
Koslicki (Kathrin) |
Constitution and Similarity |
Paper - By Subtopic  |
Philosophical Studies, Vol. 117, No. 3 (Feb., 2004), pp. 327-364 |
6% |
Maurin (Anna-Sofia) |
Same But Different |
Paper - By Subtopic  |
Metaphysica 6.1 (2005), pp. 129-148 |
No |
Morreau (Michael) |
It Simply Does Not Add Up: Trouble With Overall Similarity |
Paper - By Subtopic  |
The Journal of Philosophy, Vol. 107, No. 9 (Sept. 2010), pp. 469-490 |
No |
Shoemaker (David) |
Personal Identity and Ethics - Introduction |
Paper - Referencing  |
Shoemaker (David) - Personal Identity and Ethics: A Brief Introduction, 2009, Introduction |
Yes |
Shoemaker (David) |
Personal Identity and Ethics: A Brief Introduction |
Book - Referencing (via Paper Referencing)  |
Bibliographical details to be supplied |
Yes |
Shoemaker (Sydney) |
Identity, Cause and Mind |
Book - By Subtopic (via Paper By Subtopic)  |
Shoemaker (Sydney) - Identity, Cause and Mind |
5% |
Shoemaker (Sydney) |
Phenomenal Similarity |
Paper - By Subtopic |
Shoemaker - Identity, Cause and Mind |
No |
Suchow (Jordan) |
Haven’t we met before? On doppelgängers and perception |
Paper - Cited  |
Aeon, 09 May, 2018 |
Yes |
Todman (Theo) |
Thesis - Similarity |
Paper - By Subtopic  |
|
Yes |
Vander Laan (David) |
Counterpossibles and Similarity |
Paper - By Subtopic |
Jackson - Lewisian Themes: The Philosophy of David K. Lewis, Chapter 20 |
No |
Text Colour Conventions
- Blue: Text by me; © Theo Todman, 2023