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Single Idea 19057

[filed under theme 5. Theory of Logic / G. Quantification / 1. Quantification ]

Full Idea

Classical quantification represents an infinite conjunction or disjunction, and the truth-value is determined by the infinite sum or product of the instances ....but this presupposes that all the instances already possess determinate truth-values.

Gist of Idea

Classical quantification is an infinite conjunction or disjunction - but you may not know all the instances

Source

Michael Dummett (The philosophical basis of intuitionist logic [1973], p.246)

Book Ref

Dummett,Michael: 'Truth and Other Enigmas' [Duckworth 1978], p.246


A Reaction

In the case of the universal quantifier, Dummett is doing no more than citing the classic empiricism objection to induction - that you can't make the universal claim if you don't know all the instances. The claim is still meaningful, though.


The 23 ideas with the same theme [general ideas about expressing quantities of objects]:

Affirming/denying sentences are universal, particular, or indeterminate [Aristotle]
The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham]
A quantifier is a second-level predicate (which explains how it contributes to truth-conditions) [Frege, by George/Velleman]
'Any' is better than 'all' where infinite classes are concerned [Russell]
Wittgenstein tried unsuccessfully to reduce quantifiers to conjunctions and disjunctions [Wittgenstein, by Jacquette]
Objects are the values of variables, so a referentially opaque context cannot be quantified into [Quine]
Universal quantification is widespread, but it is definable in terms of existential quantification [Quine]
Quantifying into referentially opaque contexts often produces nonsense [Quine]
No sense can be made of quantification into opaque contexts [Quine, by Hale]
Finite quantification can be eliminated in favour of disjunction and conjunction [Quine, by Dummett]
Nominalists should quantify existentially at first-order, and substitutionally when higher [Marcus (Barcan)]
Traditional quantifiers combine ordinary language generality and ontology assumptions [Harré]
Classical quantification is an infinite conjunction or disjunction - but you may not know all the instances [Dummett]
'Prenex normal form' is all quantifiers at the beginning, out of the scope of truth-functors [Bostock]
The quantifier is overrated as an analytical tool [McGinn]
Existential quantifiers just express the quantity of things, leaving existence to the predicate 'exists' [McGinn]
Quantifiers turn an open sentence into one to which a truth-value can be assigned [Mautner]
Not all quantification is either objectual or substitutional [Williamson]
Quantifiers are second-order predicates [Read]
Traditionally, universal sentences had existential import, but were later treated as conditional claims [Orenstein]
The quantifier in logic is not like the ordinary English one (which has empty names, non-denoting terms etc) [Hofweber]
The inferential quantifier focuses on truth; the domain quantifier focuses on reality [Hofweber]
Conjunctive and disjunctive quantifiers are too specific, and are confined to the finite [Morris,M]