5 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) |
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) |
19508 | Contextualism needs a semantics for knowledge sentences that are partly indexical [Schiffer,S] |
Full Idea: Contextualist semantics must capture the 'indexical' nature of knowledge claims, the fact that different utterances of a knowledge sentence with no apparent indexical terms can express different propositions. | |
From: Stephen Schiffer (Contextualist Solutions to Scepticism [1996], p.325), quoted by Keith DeRose - The Case for Contextualism 1.5 | |
A reaction: Schiffer tries to show that this is too difficult, and DeRose defends contextualism against the charge. |
19509 | The indexical aspect of contextual knowledge might be hidden, or it might be in what 'know' means [Schiffer,S] |
Full Idea: One might have a 'hidden-indexical' theory of knowledge sentences: they contain constituents that are not the semantic values of any terms; ...or 'to know' itself might be indexical, as in 'I know[easy] I have hands' or 'I know[tough] I have hands'. | |
From: Stephen Schiffer (Contextualist Solutions to Scepticism [1996], p.326-7), quoted by Keith DeRose - The Case for Contextualism 1.5 | |
A reaction: [very compressed] Given the choice, I would have thought it was in 'know', since to say 'either you know p or you don't' sounds silly to me. |
20921 | How can we state relativism of sweet and sour, if they have no determinate nature? [Theophrastus] |
Full Idea: How could what is bitter for us be sweet and sour for others, if there is not some determinate nature for them? | |
From: Theophrastus (On the Senses [c.321 BCE], 70) | |
A reaction: The remark is aimed at Democritus. This is part of the general question of how you can even talk about relativism, without attaching stable meanings to the concepts employed. |