Ruth Barcan Marcus
Logic can reason about what is possible and necessary, and a proper name is just a tag for a thing, not a hidden description of it.
Placement
Logician who in 1946, at the same time as Carnap, published one of the first systems combining quantifiers with modal operators: the “Barcan formula” and her account of proper names as mere “tags” without descriptive content anticipated later theories of reference.
Key ideas
- Quantified modal logic
- Barcan formula
- Names as tags
Influence
Influenced 1
Saul Kripke
influenced disputed
Kripke’s models for quantified modal logic (1959, 1963) took up Barcan’s systems and formula (1946); whether rigid designation derives from her ‘tags’ (1961) is disputed. R. C. Barcan, “A Functional Calculus of First Order Based on Strict Implication”, Journal of Symbolic Logic 11 (1946); R. Barcan Marcus, “Modalities and Intensional Languages”, Synthese 13 (1961); S. A. Kripke, “Semantical Considerations on Modal Logic” (1963); Naming and Necessity (lectures 1970; publ. 1972, 1980); Q. Smith and S. Soames, Synthese 104 (1995); SEP “Ruth Barcan Marcus”
Evidence: AI draft
Saul Kripke › 1940–2022
Criticism
Mutual critique 1
W. V. O. Quine ⇄ mutual
criticised
Against Quine, Barcan Marcus argued that quantified modal logic is coherent: proper names are mere ‘tags’, and identities between them hold necessarily (‘Modalities and Intensional Languages’, 1961). R. Barcan Marcus, “Modalities and Intensional Languages”, Synthese 13 (1961), 303–322, with Quine’s comments (Boston Colloquium)
Evidence: AI draft
criticised by
Quine objected that quantified modal logic, which Barcan Marcus first formalised (1946), founders on referential opacity and commits one to ‘Aristotelian essentialism’ (‘Reference and Modality’, 1953). W. V. O. Quine, “Reference and Modality”, in From a Logical Point of View (1953); “Three Grades of Modal Involvement” (1953); R. C. Barcan, Journal of Symbolic Logic 11 (1946)
Evidence: AI draft
W. V. O. Quine › 1908–2000
Works
The first published system of quantified modal logic – containing the formula later named after her.
Proper names are mere tags; identity is necessary – a defence of modal logic against Quine’s objections.
Position
Her 1946 papers gave the first systems of quantified modal logic, combining necessity and possibility with quantifiers; the “Barcan formula”, which says that if it is possible that something has a property then something possibly has it, became a standard topic. Quine argued that quantifying into modal contexts was incoherent; Marcus defended it. In “Modalities and Intensional Languages” she proposed that proper names are mere “tags” with no descriptive meaning, so that identity statements between names, if true, are necessarily true – a view close to what Kripke later made famous as rigid designation; the question of priority has been debated.
Life & context
Ruth Barcan Marcus (1921–2012) was born in New York, studied mathematics and philosophy at New York University and took her doctorate at Yale under Frederic Fitch in 1946. She taught at Roosevelt University, the University of Illinois at Chicago and Northwestern before returning to Yale in 1973. She was a founding member and chair of the National Board of the American Philosophical Association and active in international logic organisations.
Further main works
- Moral Dilemmas and Consistency (1980)
- Modalities: Philosophical Essays (1993)
Appears in
- Journey ‘From Gargi to Oluwole’ · Stop 9 of 10
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