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Single Idea 5745

[filed under theme 4. Formal Logic / D. Modal Logic ML / 1. Modal Logic ]

Full Idea

Quine charges quantified modal systems of logic with giving rise to unintended sense or nonsense, committing us to an incomprehensible ontology, and entailing an implausible or unsustainable Aristotelian essentialism.

Clarification

'Quantified modal systems' use quantifiers in possible worlds instead of necessity/possibility

Gist of Idea

Quine says quantified modal logic creates nonsense, bad ontology, and false essentialism

Source

comment on Willard Quine (Existence and Quantification [1966]) by Joseph Melia - Modality Ch.3

Book Ref

Melia,Joseph: 'Modality' [Acumen 2003], p.63


A Reaction

A nice summary. Personally I like essentialism in accounts of science (see Nature|Laws of Nature|Essentialism), so would like to save it in metaphysics. Possible worlds ontology may be very surprising, rather than 'incomprehensible'.


The 18 ideas with the same theme [general ideas about the nature of modal logic]:

Modal Square 1: □P and ¬◊¬P are 'contraries' of □¬P and ¬◊P [Aristotle, by Fitting/Mendelsohn]
Modal Square 2: ¬□¬P and ◊P are 'subcontraries' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn]
Modal Square 3: □P and ¬◊¬P are 'contradictories' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn]
Modal Square 4: □¬P and ¬◊P are 'contradictories' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn]
Modal Square 5: □P and ¬◊¬P are 'subalternatives' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn]
Modal Square 6: □¬P and ¬◊P are 'subalternatives' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn]
Quine says quantified modal logic creates nonsense, bad ontology, and false essentialism [Melia on Quine]
Quantified modal logic collapses if essence is withdrawn [Quine]
Maybe we can quantify modally if the objects are intensional, but it seems unlikely [Quine]
It was realised that possible worlds covered all modal logics, if they had a structure [Dummett]
Propositional modal logic has been proved to be complete [Kripke, by Feferman/Feferman]
Kripke's modal semantics presupposes certain facts about possible worlds [Kripke, by Zalta]
Possible worlds allowed the application of set-theoretic models to modal logic [Kripke]
The interest of quantified modal logic is its metaphysical necessity and essentialism [Soames]
Modal operators are usually treated as quantifiers [Shapiro]
Modal logic gives an account of metalogical possibility, not metaphysical possibility [Burgess/Rosen]
First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia]
Simple Quantified Modal Logc doesn't work, because the Converse Barcan is a theorem [Merricks]