6 ideas
| 13768 | Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington] |
| Full Idea: If your interest in logic is confined to applications to mathematics or other a priori matters, it is fine for validity to preserve certainty, ..but if you use conditionals when arguing about contingent matters, then great caution will be required. | |
| From: Dorothy Edgington (Conditionals [2001], 17.2.1) |
| 13770 | There are many different conditional mental states, and different conditional speech acts [Edgington] |
| Full Idea: As well as conditional beliefs, there are conditional desires, hopes, fears etc. As well as conditional statements, there are conditional commands, questions, offers, promises, bets etc. | |
| From: Dorothy Edgington (Conditionals [2001], 17.3.4) |
| 13764 | Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington] |
| Full Idea: Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? Are they non-truth-functional, like 'because' or 'before'? Do the values of A and B, in some cases, leave open the value of 'If A,B'? | |
| From: Dorothy Edgington (Conditionals [2001], 17.1) | |
| A reaction: I would say they are not truth-functional, because the 'if' asserts some further dependency relation that goes beyond the truth or falsity of A and B. Logical ifs, causal ifs, psychological ifs... The material conditional ⊃ is truth-functional. |
| 13765 | 'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington] |
| Full Idea: If it were possible to have A true, B false, and If A,B true, it would be unsafe to infer B from A and If A,B: modus ponens would thus be invalid. Hence 'If A,B' must entail ¬(A & ¬B). | |
| From: Dorothy Edgington (Conditionals [2001], 17.1) | |
| A reaction: This is a firm defence of part of the truth-functional view of conditionals, and seems unassailable. The other parts of the truth table are open to question, though, if A is false, or they are both true. |
| 21932 | 'Différance' is the interwoven history of each sign [Derrida, by Glendinning] |
| Full Idea: What Derrida calls 'différance' can be understood as the movement through which every sign is 'constituted historically as a weave of differences'....This replacement for 'speech' in the 'origin' of the system is to avoid the circularity in structuralism. | |
| From: report of Jacques Derrida (Différance [1982]) by Simon Glendinning - Derrida: A Very Short Introduction 5 | |
| A reaction: [compressed] Struggling to grasp this. Some English words entirely change their meaning over time (e.g. buxom). Does the lost meaning remain part of the new meaning? If so, how? He also calls différance 'sameness which is not identical'. |
| 22395 | Moral judgements are hypothetical, because they depend on interests and desires [Foot] |
| Full Idea: Moral judgements are hypothetical imperatives in the sense that they give reasons for acting only in conjunction with interests and desires. | |
| From: Philippa Foot (Reply to Professor Frankena [1975], p.177) | |
| A reaction: This is a splendid claim, which points to a more sensibly naturalistic ethics. There seem to be occasions for moral behaviour where I have no interests or desires, such as when a stranger asks me for a favour and I'm feeling tired. |