("Modalities and Intensional Languages," in Synthése, Vol.
Marcus asserted these transpositions in what are now called the "Barcan formulas." Willard Van Orman Quine mostly ignored Lewis's modal logic, and he reacted negatively to Marcus's suggestion in 1946 that modality operators (a box '◻' for "necessarily" and a diamond '◇' for "possibly") could be transposed or interchanged with quantification operators (an inverted A '∀' for "for all" and a reversed E '∃' for "for some"), while preserving the truth values of the statements or propositions. Lewis reinvented modal logic in the 1920's and tried to add it to the symbolic logic of the great Principia Mathematica of Russell and Alfred North Whitehead. Aristotle's logic also contained the modal notions of necessity ("must") and possibility ("may"), but modality had disappeared from texts on symbolic logic since Gottlob Frege and Bertrand Russell had reduced philosophy to a "truth-functional" analysis of statements that are plain assertions - true or false.įor them and for Ludwig Wittgenstein and Rudolf Carnap, all of knowledge in general and science in particular is reducible to the collection of all true statements.Ĭ.
The original predicate logic developed by Aristotle in his Prior Analytics contained the quantifiers "for some" and "for all" - e.g., all men are mortal. She is said to have created "quantified modal logic." Ruth Barcan Marcus was a philosopher of logic who restored the "modal" concepts of necessity and possibility to the "quantified" logic that analyzes truths in terms of set membership.
Henry Quastler Adolphe Quételet Lord Rayleigh Jürgen Renn Juan Roederer Jerome Rothstein David Ruelle Tilman Sauer
0 kommentar(er)
