6 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. |
| 23222 | A soul with physical extension is more likely than an immaterial soul that moves bodies [Elizabeth] |
| Full Idea: I would find it easier to concede matter and extension to the soul than to concede that an immaterial thing could move and be moved by a body. | |
| From: Elizabeth, Princess of Bohemia (Letters to Descartes [1643], p.42), quoted by Matthew Cobb - The Idea of the Brain 2 | |
| A reaction: Very nicely expressed! I'm trying to imagine a ghost which finds itself stuck with a physical body which it has to drag around like a reluctant dog. She is stating the classic interaction problem which plagues all mind-body dualism. |
| 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). |
| 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). |