display all the ideas for this combination of texts
3 ideas
| 13827 | Logical consequence isn't a black box (Tarski's approach); we should explain how arguments work [Prawitz] |
| Full Idea: Defining logical consequence in the way Tarski does is a rather meagre result, treating an argument as a black box, observing input and output, while disregarding inner structure. We should define logical consequence on the basis of valid arguments. | |
| From: Dag Prawitz (On the General Idea of Proof Theory [1974], §2) |
| 8312 | It is better if the existential quantifier refers to 'something', rather than a 'thing' which needs individuation [Lowe] |
| Full Idea: If we take the existential quantifier to mean 'there is at least one thing that' then its value must qualify as one thing, individuable in principle. ...So I propose to read it as 'there is something that', which implies nothing about individuability. | |
| From: E.J. Lowe (The Possibility of Metaphysics [1998], 11) | |
| A reaction: All sorts of doubts about the existential quantifier seem to be creeping in nowadays (e.g. Ideas 6067, 6069, 8250). Personally I am drawn to the sound of 'free logic', Idea 8250, which drops existential claims. This would reduce metaphysical confusion. |
| 13826 | Model theory looks at valid sentences and consequence, but not how we know these things [Prawitz] |
| Full Idea: In model theory, which has dominated the last decades, one concentrates on logically valid sentences, and what follows logically from what, but one disregards questions concerning how we know these things. | |
| From: Dag Prawitz (On the General Idea of Proof Theory [1974], §1) |