7 ideas
| 11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
| Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], II) | |
| A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts. |
| 11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
| Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table. | |
| From: Ian Rumfitt ("Yes" and "No" [2000]) | |
| A reaction: This is the standard view which Rumfitt sets out to challenge. |
| 11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
| Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], III) | |
| A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value. |
| 9052 | Vague predicates lack application; there are no borderline cases; vague F is not F [Unger, by Keefe/Smith] |
| Full Idea: In a slogan, Unger's thesis is that all vague predicates lack application ('nihilism', says Williamson). Classical logic can be retained in its entirety. There are no borderline cases: for vague F, everything is not F; nothing is either F or borderline F. | |
| From: report of Peter Unger (There are no ordinary things [1979]) by R Keefe / P Smith - Intro: Theories of Vagueness §1 | |
| A reaction: Vague F could be translated as 'I'm quite tempted to apply F', in which case Unger is right. This would go with Russell's view. Logic and reason need precise concepts. The only strategy with vagueness is to reason hypothetically. |
| 16070 | There are no objects with proper parts; there are only mereological simples [Unger, by Wasserman] |
| Full Idea: Eliminativism is often associated with Unger, who defends 'mereological nihilism', that there are no composite objects (objects with proper parts); there are only mereological simples (with no proper parts). The nihilist denies statues and ships. | |
| From: report of Peter Unger (There are no ordinary things [1979]) by Ryan Wasserman - Material Constitution 4 | |
| A reaction: The puzzle here is that he has a very clear notion of identity for the simples, but somehow bars combinations from having identity. So identity is simplicity? 'Complex identity' doesn't sound like an oxymoron. We're stuck if there are no simples. |
| 11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
| Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], IV) | |
| A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role). |
| 5271 | Prejudice apart, push-pin has equal value with music and poetry [Bentham] |
| Full Idea: Prejudice apart, the game of push-pin is of equal value with the arts and science of music and poetry. | |
| From: Jeremy Bentham (Constitutional Code I [1827], p.139), quoted by J.R. Dinwiddy - Bentham p.114 | |
| A reaction: Mill quoted this with implied outrage, but Bentham was attacking public subsidies to the arts when he said it. It is a basic idea in the debate on pleasure - that pleasures are only distinguished by their intensity, not some other value. |