15 ideas
19504 | My modus ponens might be your modus tollens [Pritchard,D] |
Full Idea: One philosopher's modus ponens is another philosopher's modus tollens. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 3.§2) | |
A reaction: [Anyone know the originator of this nice thought?] You say A is true, and A proves B, so B is true. I reply that if A proves something as daft as B, then so much the worse for A. Ain't it the truth? |
7726 | Aristotelian logic dealt with inferences about concepts, and there were also proposition inferences [Weiner] |
Full Idea: Till the nineteenth century, it was a common view that Aristotelian logic could evaluate inferences whose validity was based on relations between concepts, while propositional logic could evaluate inferences based on relations between propositions. | |
From: Joan Weiner (Frege [1999], Ch.3) | |
A reaction: Venn diagrams relate closely to Aristotelian syllogisms, as each concept is represented by a circle, and shows relations between sets. Arrows seem needed to represent how to go from one proposition to another. Is one static, the other dynamic? |
19503 | An improbable lottery win can occur in a nearby possible world [Pritchard,D] |
Full Idea: Low probability events such as lottery wins can occur in nearby possible worlds. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 2.n2) | |
A reaction: This seems to ruin any chance of mapping probabilities and counterfactuals in the neat model of nested possible worlds (like an onion). [Lewis must have thought of this, surely? - postcards, please] |
19505 | Moore begs the question, or just offers another view, or uses 'know' wrongly [Pritchard,D, by PG] |
Full Idea: The three main objections to Moore's common-sense refutation of scepticism is that it either begs the question, or it just offers a rival view instead of a refutation, or it uses 'know' in a conversationally inappropriate way. | |
From: report of Duncan Pritchard (Epistemological Disjunctivism [2012], 3.§2) by PG - Db (ideas) | |
A reaction: [I deserve applause for summarising two pages of Pritchard's wordy stuff so neatly] |
19499 | We can have evidence for seeing a zebra, but no evidence for what is entailed by that [Pritchard,D] |
Full Idea: The closure principle forces us to regard Zula as knowing that what she is looking at is not a cleverly disguised mule, and yet she doesn't appear to have any supporting evidence for this knowledge. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 2.§3) | |
A reaction: [Zula observes a zebra in the zoo] Entailment is a different type of justification from perception. If we add fallibilism to the mix, then fallibility can increase as we pursue a string of entailments. But proper logic, of course, should not be fallible. |
19500 | Favouring: an entailment will give better support for the first belief than reason to deny the second [Pritchard,D] |
Full Idea: The Favouring Principle says that if S knows two things, and that the first entails the second, then S has better evidence in support of her belief in the first than she has for denying the second. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 2.§3) | |
A reaction: [his version is full of Greek letters, but who wants that stuff?] Pritchard concludes that if you believe in the closure principle then you should deny the favouring principle. |
19502 | Maybe knowledge just needs relevant discriminations among contrasting cases [Pritchard,D] |
Full Idea: According to the 'contrastivist' proposal knowledge is to be understood as essentially involving discrimination, such that knowing a proposition boils down to having the relevant discriminatory capacities. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 2.§6) | |
A reaction: Pritchard says this isn't enough, and we must also to be aware of supporting favouring evidence. I would focus on the concept of coherence, even for simple perceptual knowledge. If I see a hawk in England, that's fine. What if I 'see' a vulture? |
19498 | Epistemic internalism usually says justification must be accessible by reflection [Pritchard,D] |
Full Idea: Typically, internal epistemic conditions are characterised in terms of a reflective access requirement. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 1.§6) | |
A reaction: If your justification is straightforwardly visual, it is unclear what the difference would be between seeing the thing and having reflective access to the seeing. |
19506 | Externalism is better than internalism in dealing with radical scepticism [Pritchard,D] |
Full Idea: Standard epistemic internalism faces an uphill struggle when it comes to dealing with radical scepticism, which points in favour of epistemic externalist neo-Mooreanism. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 3.§3) | |
A reaction: I incline towards internalism. I deal with scepticism by being a fallibilist, and adding 'but you never know' to every knowledge claim, and then getting on with life. |
19496 | Disjunctivism says perceptual justification must be both factual and known by the agent [Pritchard,D] |
Full Idea: Slogan for disjunctivism: perceptual knowledge is paradigmatically constituted by a true belief whose epistemic support is both factive (i.e. it entails the truth of the propositions believed) and reflectively accessible to the agent. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], Intro) | |
A reaction: I'm not a fan of externalism, but it could be that the factive bit achieves the knowledge, and then being able to use and answer for that knowledge may just be a bonus, and not an essential ingredient. |
19497 | Metaphysical disjunctivism says normal perceptions and hallucinations are different experiences [Pritchard,D] |
Full Idea: Metaphysical disjunctivists hold that veridical perceptual experiences are not essentially the same as the experiences involved in corresponding cases involving illusion and (especially) hallucination. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 1.§4) | |
A reaction: Metaphysical disjunctivism concerns what the experiences are; epistemological justification concerns the criteria of justification. I think. I wish Pritchard would spell things out more clearly. Indeed, I wish all philosophers would. |
19495 | Epistemic externalism struggles to capture the idea of epistemic responsibility [Pritchard,D] |
Full Idea: A fundamental difficulty for epistemic externalist positions is that it is hard on this view to capture any adequate notion of epistemic responsibility. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], Intro) | |
A reaction: He never explains the 'responsibility', but I presume that would be like an expert witness in court, vouching for their knowledge. |
19501 | We assess error against background knowledge, but that is just what radical scepticism challenges [Pritchard,D] |
Full Idea: When faced with an error-possibility we can appeal to background knowledge, as long as the error-possibility does not call into question this background knowledge. The same is not true when we focus on the radical sceptical hypothesis. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 2.§5) | |
A reaction: [reworded] Doubting everything simultaneously just looks like a mad project. If you doubt linguistic meaning, you can't even express your doubts. |
3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
Full Idea: Anaxarchus said that he was not even sure that he knew nothing. | |
From: report of Anaxarchus (fragments/reports [c.340 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.10.1 |
19507 | Radical scepticism is merely raised, and is not a response to worrying evidence [Pritchard,D] |
Full Idea: Crucially, radical sceptical error-possibilities are never epistemically motivated, but are instead merely raised. | |
From: Duncan Pritchard (Epistemological Disjunctivism [2012], 3.§5) | |
A reaction: In 'The Matrix' someone sees a glitch in the software (a cat crossing a passageway), and that would have to be taken seriously. Otherwise it is a nice strategy to ask why the sceptic is raising this bizzare possibility, without evidence. |