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. |
| 13858 | The truth-functional account of conditionals is right, if the antecedent is really acceptable [Jackson, by Edgington] |
| Full Idea: Jackson defends the truth-functional account by saying that for a conditional to be assertable, it must not only be believed that its truth-conditions are satisfied, but the belief must be robust or resilient with respect to the antecedent. | |
| From: report of Frank Jackson (Conditionals and Possibilia [1981]) by Dorothy Edgington - Do Conditionals Have Truth Conditions? 4 | |
| A reaction: ..That is, one would not abandon the conditional if one believed the antecedent to be true. |
| 4741 | A very powerful computer might have its operations restricted by the addition of consciousness [Clark,T] |
| Full Idea: It seems possible that if a powerful multi-tasking computer was then given consciousness, this might restrict its operations instead of enhancing them. | |
| From: Tom Clark (talk [2003]), quoted by PG - Db (ideas) | |
| A reaction: A nice thought, because it challenges the usual view - that consciousness brings huge intellectual liberty to a mind, and that a mind without it is necessarily restricted. Maybe consciousness is a bottleneck. |
| 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). |