8 ideas
| 15716 | If axioms and their implications have no contradictions, they pass my criterion of truth and existence [Hilbert] |
| Full Idea: If the arbitrarily given axioms do not contradict each other with all their consequences, then they are true and the things defined by the axioms exist. For me this is the criterion of truth and existence. | |
| From: David Hilbert (Letter to Frege 29.12.1899 [1899]), quoted by R Kaplan / E Kaplan - The Art of the Infinite 2 'Mind' | |
| A reaction: If an axiom says something equivalent to 'fairies exist, but they are totally undetectable', this would seem to avoid contradiction with anything, and hence be true. Hilbert's idea sounds crazy to me. He developed full Formalism later. |
| 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). |
| 20887 | A rape disregards the status of being a person - but so does all assault [Foa] |
| Full Idea: In a rape a person is used without proper regard for her personhood - but this is true of every kind of assault. | |
| From: Pamela Foa (What's Wrong with Rape? [1977], 1) | |
| A reaction: This is a good step towards her attempt to pin down what is specifically wrong with rape, which strikes me as an extremely important question, and not merely in order to justify punishments. |
| 20888 | Rape of children is dreadful, but no one thinks children should have a right of consent [Foa] |
| Full Idea: Rape of children is at least as heinous as rape of adults, though few believe that children have or ought to have the same large domain of consent adults (male and female) ought to have. | |
| From: Pamela Foa (What's Wrong with Rape? [1977], 1) | |
| A reaction: A powerful point. She is not quite spelling out the crux, which is that no one thinks children should have a right to consent to sexual intercourse, which means that consent is irrelevant in such a case of rape. So it can't be the key to adult rape? |
| 20889 | If men should lust and women shouldn't, that makes rape the prevalent sexual model [Foa] |
| Full Idea: We are taught that sexual desires are desires women ought not to have and men must have. This is the model which makes necessary an eternal battle of the sexes. It explains why rape is the prevalent model of sexuality. | |
| From: Pamela Foa (What's Wrong with Rape? [1977], 3) | |
| A reaction: A striking thought. See 'The Origins of Sex' by F.Dabhoiwala, which claims that women used to be seen as the sexual predators, and the balance shifted in the 18thC. Are women obliged to exhibit lust, in order to defuse rapacious desires? |