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. |
| 6029 | Whoever knows future causes knows everything that will be [Cicero] |
| Full Idea: Whoever grasps the causes of future things must necessarily grasp all that will be. | |
| From: M. Tullius Cicero (On Divination ('De divinatione') [c.46 BCE], 1.127) | |
| A reaction: Laplace stated this idea in terms of Newtonian physics (Idea 3441), but the key idea is stated more simply and clearly here. God can know the future in this way, without actually seeing it happen now. I can't think why it should not be true. |
| 22235 | Feelings are not unchanging, but have a history (especially if they are noble) [Foucault] |
| Full Idea: We believe that feelings are immutable, but every sentiment, particularly the most noble and disinterested, has a history. | |
| From: Michel Foucault (Nietzsche, Genealogy, History [1971], p.86), quoted by Johanna Oksala - How to Read Foucault 5 | |
| A reaction: This is the sort of remark that makes me think Foucault is worth reading. Aristotle thought you could teach correct feelings. That implies that you can also teach incorrect feelings. |
| 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). |