3 ideas
| 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'. |
| 14305 | In the truth-functional account a burnt-up match was soluble because it never entered water [Carnap] |
| Full Idea: If a wooden match was completely burned up yesterday, and never placed in water at any time, is it not the case, therefore, that the match is soluble (in the truth-functional view). This follows just from the antecedent being false. | |
| From: Rudolph Carnap (Testability and Meaning [1937], I.440), quoted by Stephen Mumford - Dispositions | |
| A reaction: This, along with Edgington's nice example of the conditional command (Idea ) seems conclusive against the truth-functional account. The only defence possible is some sort of pragmatic account about implicature. |
| 8338 | A phenomenalist about objects has to be a regularity theorist about causation [Strawson,G] |
| Full Idea: If you are a phenomenalist about objects, then there is an important sense in which you ought to be a Regularity theorist about what causation is, in such objects. | |
| From: Galen Strawson (The Secret Connexion [1989], App C) | |
| A reaction: Strawson is denying that Hume is a phenomenalist. One might go a little further, and say that a phenomenalist should abandon the idea of causation (as Russell did). |