3 ideas
15130 | If a property is possible, there is something which can have it [Williamson] |
Full Idea: Barcan's axiom says if there can be something that has a certain property, then there is something that can have that property. It and its converse are not obviously correct or incorrect. They claim that it is non-contingent what individuals there are. | |
From: Timothy Williamson (Laudatio: Prof Ruth Barcan Marcus [2011], p.1) | |
A reaction: Williamson defends the two Barcan formulas, but the more I understand them the less plausible they sound to me. |
10792 | The substitutional quantifier is not in competition with the standard interpretation [Kripke, by Marcus (Barcan)] |
Full Idea: Kripke proposes that the substitutional quantifier is not a replacement for, or in competition with, the standard interpretation. | |
From: report of Saul A. Kripke (A Problem about Substitutional Quantification? [1976]) by Ruth Barcan Marcus - Nominalism and Substitutional Quantifiers p.165 |
13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
Full Idea: Archimedes gave a sort of definition of 'straight line' when he said it is the shortest line between two points. | |
From: report of Archimedes (fragments/reports [c.240 BCE]) by Gottfried Leibniz - New Essays on Human Understanding 4.13 | |
A reaction: Commentators observe that this reduces the purity of the original Euclidean axioms, because it involves distance and measurement, which are absent from the purest geometry. |