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. |
6019 | If someone squashed a horse to make a dog, something new would now exist [Mnesarchus] |
Full Idea: If, for the sake of argument, someone were to mould a horse, squash it, then make a dog, it would be reasonable for us on seeing this to say that this previously did not exist but now does exist. | |
From: Mnesarchus (fragments/reports [c.120 BCE]), quoted by John Stobaeus - Anthology 179.11 | |
A reaction: Locke would say it is new, because the substance is the same, but a new life now exists. A sword could cease to exist and become a new ploughshare, I would think. Apply this to the Ship of Theseus. Is form more important than substance? |
20523 | Property is theft! [Proudhon] |
Full Idea: Property is theft! | |
From: Pierre-Joseph Proudhon (What is Property? [1840]), quoted by Jonathan Wolff - An Introduction to Political Philosophy (Rev) | |
A reaction: [Context in Proudhon's book?] This may not be the essence of property rights today, but it is almost undeniable as a historical fact. William the Conqueror kills the opposition in battle, and then gives English land to his friends. |