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Single Idea 4885
[filed under theme 9. Objects / F. Identity among Objects / 1. Concept of Identity
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Full Idea
The truth of "a=b" doesn't require much of 'a' and 'b' other than that there is a single thing to which they both refer. They needn't be interdefinable, or have supervenient properties. In this sense, identity is a very weak relation.
Gist of Idea
Identity is a very weak relation, which doesn't require interdefinability, or shared properties
Source
John Perry (Knowledge, Possibility and Consciousness [2001], §1.2)
Book Ref
Perry,John: 'Knowledge, Possibility and Consciousness' [MIT 2001], p.6
A Reaction
Interesting. This is seeing the epistemological aspects of identity. Ontologically, identity must invoke Leibniz's Law, and is the ultimately powerful 'relation'. A given student, and the cause of a crop circle, may APPEAR to be quite different.
The
14 ideas
from 'Knowledge, Possibility and Consciousness'
4885
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Identity is a very weak relation, which doesn't require interdefinability, or shared properties
[Perry]
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4884
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Brain states must be in my head, and yet the pain seems to be in my hand
[Perry]
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4887
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We try to cause other things to occur by causing mental events to occur
[Perry]
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4888
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It seems plausible that many animals have experiences without knowing about them
[Perry]
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4889
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Although we may classify ideas by content, we individuate them differently, as their content can change
[Perry]
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4890
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A sharp analytic/synthetic line can rarely be drawn, but some concepts are central to thought
[Perry]
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4891
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If epiphenomenalism just says mental events are effects but not causes, it is consistent with physicalism
[Perry]
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4892
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If physicalists stick with identity (not supervenience), Martian pain will not be like ours
[Perry]
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4896
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The intension of an expression is a function from possible worlds to an appropriate extension
[Perry]
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4897
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A proposition is a set of possible worlds for which its intension delivers truth
[Perry]
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4900
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Prior to Kripke, the mind-brain identity theory usually claimed that the identity was contingent
[Perry]
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4901
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Truth has to be correspondence to facts, and a match between relations of ideas and relations in the world
[Perry]
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4899
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Possible worlds thinking has clarified the logic of modality, but is problematic in epistemology
[Perry]
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4898
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Possible worlds are indices for a language, or concrete realities, or abstract possibilities
[Perry]
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