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. |
| 19525 | If the only aim is to believe truths, that justifies recklessly believing what is unsupported (if it is right) [Conee/Feldman] |
| Full Idea: If it is intellectually required that one try to believe all and only truths (as Chisholm says), ...then it is possible to believe some unsubstantiated proposition in a reckless endeavour to believe a truth, and happen to be right. | |
| From: E Conee / R Feldman (Evidentialism [1985], 'Justification') | |
| A reaction: This implies doxastic voluntarism. Sorry! I meant, this implies that we can control what we believe, when actually we believe what impinges on us as facts. |
| 19524 | We don't have the capacity to know all the logical consequences of our beliefs [Conee/Feldman] |
| Full Idea: Our limited cognitive capacities lead Goldman to deny a principle instructing people to believe all the logical consequences of their beliefs, since they are unable to have the infinite number of beliefs that following such a principle would require. | |
| From: E Conee / R Feldman (Evidentialism [1985], 'Doxastic') | |
| A reaction: This doesn't sound like much of an objection to epistemic closure, which I took to be the claim that you know the 'known' entailments of your knowledge. |
| 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). |
| 7417 | God can't have silly perfections, but how do we decide which ones are 'silly'? [Joslin] |
| Full Idea: It is clear that God cannot have all conceivable perfections, because otherwise he would have absurd perfections (like being the perfect prawn sandwich), so a line must be drawn, and how are we to decide which perfections are appropriate and essential? | |
| From: Jack Joslin (talk [2006]), quoted by PG - Db (ideas) | |
| A reaction: This is an excellent question for curbing the absurdities of those who want to load God with every good thing that can possibly be conceived. Is the God who is also a perfect prawn sandwich more perfect than the one who isn't? |