3 ideas
9879 | NF has no models, but just blocks the comprehension axiom, to avoid contradictions [Quine, by Dummett] |
Full Idea: Quine's New Foundations system of set theory, devised with no model in mind, but on the basis of a hunch that a purely formal restriction on the comprehension axiom would block all contradictions. | |
From: report of Willard Quine (New Foundations for Mathematical Logic [1937]) by Michael Dummett - Frege philosophy of mathematics Ch.18 | |
A reaction: The point is that Quine (who had an ontological preference for 'desert landscapes') attempted to do without an ontological commitment to objects (and their subsequent models), with a purely formal system. Quine's NF is not now highly regarded. |
12185 | Logical necessity is epistemic necessity, which is the old notion of a priori [Edgington, by McFetridge] |
Full Idea: Edgington's position is that logical necessity is an epistemic notion: epistemic necessity which, she claims, is the old notion of the a priori. Like Kripke, she thinks this is two-way independent of metaphysical necessity. | |
From: report of Dorothy Edgington (Epistemic and Metaphysical Possibility [1985]) by Ian McFetridge - Logical Necessity: Some Issues §1 | |
A reaction: [her paper was unpublished] She hence thinks an argument can be logically valid, while metaphysically its conclusion may not follow. Dubious, though I think I favour the view that logical necessity is underwritten by metaphysical necessity. |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |