3 ideas
21461 | I tried to be unsystematic and piecemeal, but failed; my papers presuppose my other views [Lewis] |
Full Idea: I should have like to be a piecemeal, unsystematic philosopher, offering independent proposals on a variety of topics. It was not be. I succumbed too often to the temptation to presuppose my views on one topic when writing on another. | |
From: David Lewis (Introduction to Philosophical Papers I [1983], p.1) | |
A reaction: He particularly mentions his possible worlds realism as a doctrine which coloured all his other work. A charming insight into the mind of a systematic thinker (called by someone 'the most systematic metaphysician since Leibniz'). |
13547 | Limitation of Size is weak (Fs only collect is something the same size does) or strong (fewer Fs than objects) [Boolos, by Potter] |
Full Idea: Weak Limitation of Size: If there are no more Fs than Gs and the Gs form a collection, then Fs form a collection. Strong Limitation of Size: A property F fails to be collectivising iff there are as many Fs as there are objects. | |
From: report of George Boolos (Iteration Again [1989]) by Michael Potter - Set Theory and Its Philosophy 13.5 |
17743 | De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki] |
Full Idea: In 1846 De Morgan introduced the enormously influential notion of a possibly arbitrary and stipulated 'universe of discourse'. It replaced Boole's original - and metaphysically a bit suspect - universe of 'all things'. | |
From: report of Augustus De Morgan (works [1846]) by Michal Walicki - Introduction to Mathematical Logic History D.1.1 | |
A reaction: This not only brings formal logic under control, but also reflects normal talk, because there is always an explicit or implicit domain of discourse when we talk. Of virtually any conversation, you can say what it is 'about'. |