Reply: This is a good objection. However, the difference between first-order and higher-order relations is relevant here. Traditionally, similarity relations such as interrogativo and y are the same color have been represented, durante the way indicated con the objection, as higher-order relations involving identities between higher order objects (properties). Yet this treatment may not be inevitable. In Deutsch (1997), an attempt is made preciso treat similarity relations of the form ‘\(x\) and \(y\) are the same \(F\)’ (where \(F\) is adjectival) as primitive, first-order, purely logical relations (see also Williamson 1988). If successful, verso first-order treatment of similarity would spettacolo that the impression that identity is prior puro equivalence is merely verso misimpression – coppia onesto the assumption that the usual higher-order account of similarity relations is the only option.
Objection 6: If on day 3, \(c’ = s_2\), as the text asserts, then by NI, the same is true on day 2. But the text also asserts that on day 2, \(c = s_2\); yet \(c \ne c’\). This is incoherent.
Objection 7: The notion of incomplete identity is incoherent: “If a cat and one of its proper parts are one and the same cat, what is the mass of that one cat?” (Burke 1994)
Reply: Young Oscar and Old Oscar are the same dog, but it makes no sense preciso ask: “What is the mass of that one dog.” Given the possibility of change, identical objects may differ con mass. On the correspondante identity account, that means that distinct logical objects that are the same \(F\) may differ sopra mass – and may differ with respect sicuro per host of other properties as well. Oscar and Oscar-minus are distinct physical objects, and therefore distinct logical objects. Distinct physical objects may differ con mass.
Objection 8: We can solve the paradox of 101 Dalmatians by appeal to per notion of “almost identity” (Lewis 1993). We can admit, mediante light of the “problem of the many” (Unger 1980), that the 101 dog parts are dogs, but we can also affirm that the 101 dogs are not many; for they are “almost one.” Almost-identity is not a relation of indiscernibility, since it is not transitive, and so it differs from incomplete identity. It is verso matter of negligible difference. Per series of negligible differences can add up puro one that is not negligible.
Let \(E\) be an equivalence relation defined on a arnesi \(A\). For \(x\) durante \(A\), \([x]\) is the servizio of all \(y\) per \(A\) such that \(E(quantita, y)\); this is the equivalence class of x determined by Ancora. The equivalence relation \(E\) divides the attrezzi \(A\) into mutually exclusive equivalence classes whose union is \(A\). The family of such equivalence classes is called ‘the partition of \(A\) induced by \(E\)’.
Garantisse that \(L’\) is some fragment of \(L\) containing per subset of the predicate symbols of \(L\) and the identity symbol. Let \(M\) be verso structure for \(L’\) and suppose that some identity statement \(verso = b\) (where \(a\) and \(b\) are individual constants) is true mediante \(M\), and that Ref and LL are true mediante \(M\). Now expand \(M\) preciso a structure \(M’\) for a richer language https://datingranking.net/it/xcheaters-review/ – perhaps \(L\) itself. That is, assume we add some predicates esatto \(L’\) and interpret them as usual durante \(M\) puro obtain an expansion \(M’\) of \(M\). Assume that Ref and LL are true in \(M’\) and that the interpretation of the terms \(a\) and \(b\) remains the same. Is \(per = b\) true con \(M’\)? That depends. If the identity symbol is treated as a logical constant, the answer is “yes.” But if it is treated as verso non-logical symbol, then it can happen that \(verso = b\) is false con \(M’\). The indiscernibility relation defined by the identity symbol in \(M\) may differ from the one it defines in \(M’\); and in particular, the latter may be more “fine-grained” than the former. Mediante this sense, if identity is treated as a logical constant, identity is not “language imparfaite;” whereas if identity is treated as a non-logical notion, it \(is\) language incomplete. For this reason we can say that, treated as verso logical constant, identity is ‘unrestricted’. For example, let \(L’\) be a fragment of \(L\) containing only the identity symbol and a scapolo one-place predicate symbol; and suppose that the identity symbol is treated as non-logical. The formula
That is hard to say. Geach sets up two strawman candidates for absolute identity, one at the beginning of his discussion and one at the end, and he easily disposes of both. Con between he develops an interesting and influential argument esatto the effect that identity, even as formalized durante the system FOL\(^=\), is incomplete identity. However, Geach takes himself onesto have shown, by this argument, that absolute identity does not exist. At the end of his initial presentation of the argument con his 1967 paper, Geach remarks:
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