25 ideas
10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
Full Idea: 'Equivocation' is when the terms do not mean the same thing in the premises and in the conclusion. | |
From: JC Beall / G Restall (Logical Consequence [2005], Intro) |
10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
Full Idea: Logic is purely formal either when it is invariant under permutation of object (Tarski), or when it has totally abstracted away from all contents, or it is the constitutive norms for thought. | |
From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
A reaction: [compressed] The third account sounds rather woolly, and the second one sounds like a tricky operation, but the first one sounds clear and decisive, so I vote for Tarski. |
10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
Full Idea: Technical work on logical consequence has either focused on proofs, where validity is the existence of a proof of the conclusions from the premises, or on models, which focus on the absence of counterexamples. | |
From: JC Beall / G Restall (Logical Consequence [2005], 3) |
10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
Full Idea: Two different views of logical consequence are necessary truth-preservation (based on modelling possible worlds; favoured by Realists), or truth-preservation based on the meanings of the logical vocabulary (differing in various models; for Anti-Realists). | |
From: JC Beall / G Restall (Logical Consequence [2005], 2) | |
A reaction: Thus Dummett prefers the second view, because the law of excluded middle is optional. My instincts are with the first one. |
10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
Full Idea: A logical step is a 'material consequence' and not a formal one, if we need the contents as well as the structure or form. | |
From: JC Beall / G Restall (Logical Consequence [2005], 2) |
10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
Full Idea: If a conclusion follows from an empty collection of premises, it is true by logic alone, and is a 'logical truth' (sometimes a 'tautology'), or, in the proof-centred approach, 'theorems'. | |
From: JC Beall / G Restall (Logical Consequence [2005], 4) | |
A reaction: These truths are written as following from the empty set Φ. They are just implications derived from the axioms and the rules. |
10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
Full Idea: Models are abstract mathematical structures that provide possible interpretations for each of the non-logical primitives in a formal language. | |
From: JC Beall / G Restall (Logical Consequence [2005], 3) |
10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
Full Idea: There are many proof-systems, the main being Hilbert proofs (with simple rules and complex axioms), or natural deduction systems (with few axioms and many rules, and the rules constitute the meaning of the connectives). | |
From: JC Beall / G Restall (Logical Consequence [2005], 3) |
19527 | We don't acquire evidence and then derive some knowledge, because evidence IS knowledge [Williamson] |
Full Idea: When we acquire new evidence in perception, we do not first acquire unknown evidence and then somehow base knowledge on it later. Rather, acquiring new is evidence IS acquiring new knowledge. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.4) | |
A reaction: This makes his point much better than Idea 19526 does. |
19528 | Knowledge is prior to believing, just as doing is prior to trying to do [Williamson] |
Full Idea: Knowing corresponds to doing, believing to trying. Just as trying is naturally understood in relation to doing, so believing is naturally understood in relation to knowing. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.4) | |
A reaction: An interesting analogy. You might infer that there can be no concept of 'belief' without the concept of 'knowledge', but we could say that it is 'truth' which is indispensible, and leave out knowledge entirely. Belief is to truth as trying is to doing? |
19529 | Belief explains justification, and knowledge explains belief, so knowledge explains justification [Williamson] |
Full Idea: If justification is the fundamental epistemic norm of belief, and a belief ought to constitute knowledge, then justification should be understood in terms of knowledge too. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.5) | |
A reaction: If we are looking for the primitive norm which motivates the whole epistemic game, then I am thinking that truth might well play that role better than knowledge. TW would have to reply that it is the 'grasped truth', rather than the 'theoretical truth'. |
19530 | A neutral state of experience, between error and knowledge, is not basic; the successful state is basic [Williamson] |
Full Idea: A neutral state covering both perceiving and misperceiving (or remembering and misrembering) is not somehow more basic than perceiving, for what unifies the case of each neutral state is their relation to the successful state. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.5-6) | |
A reaction: An alternative is Disjunctivism, which denies the existence of a single neutral state, so that there is nothing to unite the two states, and they don't have a dependence relation. Why can't there be a prior family of appearances, some of them successful? |
19536 | Knowledge-first says your total evidence IS your knowledge [Williamson] |
Full Idea: Knowledge-first equate one's total evidence with one's total knowledge. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.8) | |
A reaction: Couldn't lots of evidence which merely had a high probability be combined together to give a state we would call 'knowledge'? Many dubious witnesses confirm the truth, as long as they are independent, and agree. |
19531 | Internalism about mind is an obsolete view, and knowledge-first epistemology develops externalism [Williamson] |
Full Idea: A postulated underlying layer of narrow mental states is a myth, whose plausibility derives from a comfortingly familiar but obsolescent philosophy of mind. Knowledge-first epistemology is a further step in the development of externalism. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.6) | |
A reaction: Williamson is a real bruiser, isn't he? I don't take internalism about mind to be obsolescent at all, but now I feel so inferior for clinging to such an 'obsolescent' belief. ...But then I cling to Aristotle, who is (no doubt) an obsolete philosopher. |
19526 | Surely I am acquainted with physical objects, not with appearances? [Williamson] |
Full Idea: When I ask myself what I am acquainted with, the physical objects in front of me are far more natural candidates than their appearances. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.3) | |
A reaction: Not very impressive. The word 'acquainted' means the content of the experience, not the phenomena. Do I 'experience' the objects, or the appearances? The answer there is less obvious. If you apply it to colours, it is even less obvious. |
19513 | A contextualist coherentist will say that how strongly a justification must cohere depends on context [DeRose] |
Full Idea: If you are a coherentist and a contextualist, you'll probably want to hold that how strongly beliefs must cohere with one another in order to count as knowledge (if they are true), or to count as justified, is a contextually variable matter. | |
From: Keith DeRose (The Case for Contextualism [2009], 1.09) | |
A reaction: How exciting! He's talking about ME! Context might not only dictate the strength of the coherence, but also the range of beliefs involved. In fact all of Thagard's criteria of coherence may be subject to contextual variation. |
19514 | Classical invariantism combines fixed truth-conditions with variable assertability standards [DeRose] |
Full Idea: The great rival to contextualism is classical 'invariantism' - invariantism about the truth-conditions [for knowing], combined with variable standards for warranted assertability. | |
From: Keith DeRose (The Case for Contextualism [2009], 1.12) | |
A reaction: That is, I take it, that we might want to assert that someone 'knows' something, when the truth is that they don't. That is, either you know or you don't, but we can bend the rules as to whether we say you know. I take this view to be false. |
19515 | We can make contextualism more precise, by specifying the discrimination needed each time [DeRose] |
Full Idea: We might make the basic contextualist schema more precise ...by saying the change in content will consist in a change in the range of relevant alternatives. Higher standards would discriminate from a broader range of alternatives. | |
From: Keith DeRose (The Case for Contextualism [2009], 1.14) | |
A reaction: This would handle the 'fake barn' and 'disguised zebra' examples, by saying lower standards do not expect such discriminations. The zebra case has a lower standard than the barn case (because fake barns are the norm here). |
19510 | In some contexts there is little more to knowledge than true belief. [DeRose] |
Full Idea: I'm inclined to accept that in certain contexts the standards for knowledge are so low that little more than true belief is required. | |
From: Keith DeRose (The Case for Contextualism [2009], 1.6) | |
A reaction: DeRose emphasises that 'a little more' is needed, rather than none. The example given is where 'he knew that p' means little more than 'the information that p was available to him' (in a political scandal). |
19516 | Contextualists worry about scepticism, but they should focus on the use of 'know' in ordinary speech [DeRose] |
Full Idea: While skepticism has drawn much of the attention of contextualists, support for contextualism should also - and perhaps primarily - be looked for in how 'knows' is utilised in non-philosophical conversation. | |
From: Keith DeRose (The Case for Contextualism [2009], 1016) | |
A reaction: Contextualists say scepticism is just raising the standards absurdly high. I take it that the ordinary use of the word 'know' is obviously highly contextual, and so varied that I don't see how philosophers could 'regiment' it into invariant form. |
19511 | If contextualism is about knowledge attribution, rather than knowledge, then it is philosophy of language [DeRose] |
Full Idea: Maybe contextualism isn't a theory about knowledge at all, but about knowledge attributions. As such, it is not a piece of epistemology at all, but of philosophy of language. | |
From: Keith DeRose (The Case for Contextualism [2009], 1.7) | |
A reaction: DeRose takes this view to be wrong. At the very least this will have to include self-attributions, by the supposed knower, because I might say 'I know that p', meaning 'but only in this rather low-standard context'. |
19535 | Internalist inferentialism has trouble explaining how meaning and reference relate [Williamson] |
Full Idea: The internalist version of inferentialist semantics has particular difficulty in establishing an adequate relation between meaning and reference. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.6) | |
A reaction: I would have thought that this was a big problem for referentialist semantics too, though evidently Williamson doesn't think so. If he is saying that the meaning is in the external world, dream on. |
19533 | Inferentialist semantics relies on internal inference relations, not on external references [Williamson] |
Full Idea: On internalist inferential (or conceptual role) semantics, the inferential relations of an expression do not depend on what, if anything, it refers to, ...rather, the meaning is something like its place in a web of inferential relations. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.6) | |
A reaction: Williamson says the competition is between externalist truth-conditional referential semantics (which he favours), and this internalist inferential semantics. He is, like, an expert, of course, but I doubt whether that is the only internalist option. |
19534 | How does inferentialism distinguish the patterns of inference that are essential to meaning? [Williamson] |
Full Idea: Inferentialism faces the grave problem of separating patterns of inference that are to count as essential to the meaning of an expression from those that will count as accidental (a form of the analytic/synthetic distinction). | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.6) | |
A reaction: This sounds like a rather persuasive objection to inferentialism, though I don't personally take that as a huge objection to all internalist semantics. |
19532 | Truth-conditional referential semantics is externalist, referring to worldly items [Williamson] |
Full Idea: Truth-conditional referential semantics is an externalist programme. In a context of utterance the atomic expressions of a language refer to worldly items, from which the truth-conditions of sentences are compositionally determined. | |
From: Timothy Williamson (Knowledge First (and reply) [2014], p.6) | |
A reaction: I just don't see how a physical object can be part of the contents of a sentence. 'Dragons fly' is atomic, and meaningful, but its reference fails. 'The cat is asleep' is just words - it doesn't contain a live animal. |