I 14
Vague identity/Stalnaker: vague identity can at most occur with vague terms in identity-statements.
>
Vagueness.
Solution/counterpart theory/Stalnaker: if cross-wordly-relation between classes of deputies ((s) counterparts) exists and not between individuals themselves, then the relation must not be the one of identity, and this other relation may be vague.)
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Counterparts, >
Counterpart theory, >
Cross world identity, >
Possible worlds.
I 126
Contingent Identity/Stalnaker: it is of course not the case that the actualism requires contingent identity, the above examples can be explained away.
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Actualism.
One cannot simply reject the possibility on the basis of semantics and logic of identity. Necessary identity: that means, that the thesis that all identity is necessary is a metaphysical thesis.
>
Identity/Kripke.
I 131
Identity/necessary/contingent/Stalnaker: according to the modal quantifier theory all identity is necessary. We do not want this, e.g. a thing can have more counterparts in another possible world.
I 132
Solution: there are different ways of picking.
I 133
Vague identity/Stalnaker/Nathan SalmonVsVague Identity: (Salmon 1981
(1), 243) according to Salmon identity cannot be vague: e.g. suppose there is a pair of entities x and y so that it is vague if they are one and the same thing - then this pair is certainly not the same pair like the pair, in which this is definitely true that x is the same thing as itself - but it is not vague, if the two pairs are identical or differentiated.
I 134
Vague identity/identity statement/vague objects/Stalnaker: e.g. M is a specific piece of land within the indeterminate Mt Rainier. a) Mt. Rainier is an indefinite object: then it is wrong to say that M = Mt. Rainier. b ) If it is about a statement instead of an object: then it is indeterminate.
I 135f
Vague identity/Stalnaker: e.g. there are two fish restaurants called Bookbinder's. Only one can be the same as the original. Endurantism: Problem: "B0": (the original) is then an ambiguous term. Perdurantism: here it is clear.
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Perdurantism, cf. >
Endurantism.
I 138
Vague identity/SalmonVsVague identity/uncertainty/Stalnaker: Salmon's argument shows that if we manage to pick out two entities a and b that there then has to be a fact, whether the two are one thing or two different things (Stalnaker pro Salmon, Nathan). Conversely: if it is undetermined whether a = b, then it is uncertain what "a" refers to or what "b" refers to. But this does not give us a reason to suppose that facts together with terms have to decide this. Salmon just shows that when facts and terms do not decide that it is then indeterminate.
I 140
StalnakerVsSalmon: Salmon's vagueness is a vagueness of reference.
I 139
Identity/indefinite/Kripke: (1971
(2), 50-1) e.g. would the table T be the same in the actual world if in the past the constituting molecules were spread a little differently? Here, the answer can be vague.
I 148
Identity/one-digit predicates/Stalnaker: one cannot generally treat sentences as predications.
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Predication, >
Sentences.
E.g. x^(Hx u Gx)
is an instance of the form Fs, but
"(Hs and Gs)"
is not. Therefore, our identity-scheme is more limited than Leibniz' law is normally formulated.
>
Leibniz Principle.
I 154f
Definition essential identity/Stalnaker: all things x and y, which are identical, are essentially identical, i.e. identical in all possible worlds, in which this thing exists ((s) that means, the existence is made a prerequisite, not the identity for the existence.)
((s) necessary identity/Stalnaker/(s): here the situation is reversed: if x and y are necessarily identical, they must exist in all possible worlds - or if a thing does not exist in a possible world, it may, in the possible worlds in which it exists, not be necessarily identical).
Necessary identity/logical form:
x^(x = y)> N(x = y)
fails in the standard semantics and in counterpart theory, because a thing can exist contingently and include self-identity existence.
Counterpart theory.
Two different things may be identical, without being essentially identical, e.g. two possible worlds a and b, each possible for the respective other, and two distinct things have the same counterpart in b, namely 3. Then the pair satisfies the identity-relation in b, but because 1 exists in the world a and is from 2 different, the pair does not satisfy
N(Ex> x = y) in b.
>
Cross world identity.
1. Salmon, Wesley C. 1981. Rational prediction. British Journal for the Philosophy of Science 32 (2):115-125
2. Kripke, Saul S. Identity and NEcessity. In Milton Karl Munitz (ed.), Identity and Individuation. New York: New York University Press. pp. 135-164 (1971).
