8 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. |
| 21846 | Bergson was a rallying point, because he emphasised becomings and multiplicities [Bergson, by Deleuze] |
| Full Idea: Bergson was a rallying point for all the opposition, …not so much because of the theme of duration, as of the theory and practice of becoming of all kinds, of coexistent multiplicities. | |
| From: report of Henri Bergson (Matter and Memory [1896]) by Gilles Deleuze - A Conversation: what is it? What is it for? I | |
| A reaction: The three heroes of Deleuze are Spinoza, Nietzsche and Bergson. All philosophers are either of Being, or of Becoming, I suggest. |
| 10990 | Conditionals are truth-functional, but unassertable in tricky cases? [Grice, by Read] |
| Full Idea: The 'conversational defence' of the truth-functional view of conditionals is that a conditional may not be assertible in difficult cases. | |
| From: report of H. Paul Grice (Presupposition and Conversational Implicature [1977]) by Stephen Read - Thinking About Logic Ch.3 |
| 21854 | Bergson showed that memory is not after the event, but coexists with it [Bergson, by Deleuze] |
| Full Idea: Bergson has shown that memory is not an actual image which forms after the object has been perceived, but a virtual image coexisting with the actual perception of the object. | |
| From: report of Henri Bergson (Matter and Memory [1896]) by Gilles Deleuze - The Actual and the Virtual p.114 | |
| A reaction: It strikes me as plausible to say that all conscious life is memory. Perceiving the present instant is only possible because it endures for a tiny moment. |
| 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). |
| 10991 | Key conversational maxims are 'quality' (assert truth) and 'quantity' (leave nothing out) [Grice, by Read] |
| Full Idea: Grice particularly identified two maxims as guiding conversation: the maxim of 'quality' (that one should assert only what one believes to be true and justified), and of 'quantity' (one should not assert less than one can). | |
| From: report of H. Paul Grice (Presupposition and Conversational Implicature [1977]) by Stephen Read - Thinking About Logic Ch.3 | |
| A reaction: I think it would be very foolish to boldly embrace the second maxim when talking to strangers. If white lies are occasionally acceptable, then what is the status of the first 'maxim'? Is it a moral maxim? |