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. |
| 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). |
| 22688 | The Aristotelian idea that choices can be perceived needs literary texts to expound it [Nussbaum] |
| Full Idea: To show forth the Aristotelian claim that 'the decision rests with perception', we need - either side by side with a philosophical outline or inside it - literary texts which display the complexity, indeterminacy, and sheer difficulty of moral choice. | |
| From: Martha Nussbaum (The Golden Bowl, and Lit as Moral Philosophy [1983], II) | |
| A reaction: Berys Gaut observes that this depends on a particularist view of moral choice (usually seen as Aristotelian), with little interest in principles. |
| 7829 | God no more has human perfections than we have animal perfections [Spinoza] |
| Full Idea: To ascribe to God those attributes which make a man perfect would be as wrong as to ascribe to a man the attributes that make perfect an elephant or an ass. | |
| From: Baruch de Spinoza (Letters to Blijenburgh [1665], 1665), quoted by Matthew Stewart - The Courtier and the Heretic Ch.10 | |
| A reaction: This would be a difficulty for Aquinas's Fourth Way (Idea 1432), and one which I think Aquinas might acknowledge, given his desire that we should be humble when trying to comprehend God (Idea 1410). It leaves us struggling to grasp the concept of God. |
| 7830 | A talking triangle would say God is triangular [Spinoza] |
| Full Idea: If a triangle could speak it would say that God is eminently triangular. | |
| From: Baruch de Spinoza (Letters to Blijenburgh [1665], 1665), quoted by Matthew Stewart - The Courtier and the Heretic Ch.10 | |
| A reaction: Spinoza had a rather appealing waspish wit. This nicely dramatises an ancient idea (Idea 407). You can, of course, if you believe in God, infer some of His characteristics from His creation. But then see Hume: Ideas 1439, 6960, 6967, 1440. |