12 ideas
18823 | To say there could have been people who don't exist, but deny those possible things, rejects Barcan [Stalnaker, by Rumfitt] |
Full Idea: Stalnaker holds that there could have been people who do not actually exist, but he denies that there are things that could have been those people. That is, he denies the unrestricted validity of the Barcan Formula. | |
From: report of Robert C. Stalnaker (Counterparts and Identity [1987]) by Ian Rumfitt - The Boundary Stones of Thought 6.2 | |
A reaction: And quite right too, I should have thought. As they say, Jack Kennedy and Marilyn Monroe might have had a child, but the idea that we should accept some entity which might have been that child but wasn't sounds like nonsense. Except as fiction….. |
11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation. | |
From: Ian Rumfitt ("Yes" and "No" [2000], II) | |
A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts. |
11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table. | |
From: Ian Rumfitt ("Yes" and "No" [2000]) | |
A reaction: This is the standard view which Rumfitt sets out to challenge. |
11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious. | |
From: Ian Rumfitt ("Yes" and "No" [2000], III) | |
A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value. |
16409 | Unlike Lewis, I defend an actualist version of counterpart theory [Stalnaker] |
Full Idea: I defend a version of counterpart theory that is quite different from Lewis's version, as it is tied to actualism (all that exists is part of the actual world) rather than possibilism (possible things may exist without actually existing). | |
From: Robert C. Stalnaker (Counterparts and Identity [1987], 1) | |
A reaction: This could be the theory I am after. I am sympathetic to both actualism and to counterpart theory. Off to the woodshed…. |
16411 | If possible worlds really differ, I can't be in more than one at a time [Stalnaker] |
Full Idea: Nothing can be in two places at once. If other possible worlds are really other universes, then clearly, you and I cannot be in them if we are here in this one. | |
From: Robert C. Stalnaker (Counterparts and Identity [1987], 2) | |
A reaction: This can be sensibly expressed without possible worlds. I can't embody my other possibilities while I am embodying this one (I'm too busy). Insofar as possible worlds are a good framework, they are just a precise map of common sense. |
16412 | If counterparts exist strictly in one world only, this seems to be extreme invariant essentialism [Stalnaker] |
Full Idea: Counterparts involve the thesis that domains of different possible worlds are disjoint: possible individuals exist in at most one possible world. This seems to suggest extreme essentialism, where nothing could differ from how it is. | |
From: Robert C. Stalnaker (Counterparts and Identity [1987], 2) | |
A reaction: He quotes Salmon (1981:236) as saying counterpart theory is particularly inflexible essentialism. This is a long way from my use of 'essentialism'. The problem is just the extent to which my counterpart is 'the same' as me. |
19730 | Epistemic virtues: love of knowledge, courage, caution, autonomy, practical wisdom... [Kvanvig] |
Full Idea: Virtue theorists may focus on the particular habits or virtues of successful cognizers, such as love of knowledge, firmness, courage and caution, humility, autonomy, generosity, and practical wisdom. | |
From: Jonathan Kvanvig (Virtue Epistemology [2011], III) | |
A reaction: [He cites Roberts and Wood 2007] It is interesting that most of these virtues do not merely concern cognition. How about diligence, self-criticism, flexibility...? |
19731 | If epistemic virtues are faculties or powers, that doesn't explain propositional knowledge [Kvanvig] |
Full Idea: Conceiving of the virtues in terms of faculties or powers doesn't help at all with the problem of accounting for propositional knowledge. | |
From: Jonathan Kvanvig (Virtue Epistemology [2011], IV B) | |
A reaction: It always looks as if epistemic virtues are a little peripheral to the main business of knowledge, which is getting beliefs to be correct and well-founded. Given that epistemic saints make occasional mistakes, talk of virtues can't be enough. |
19732 | The value of good means of attaining truth are swamped by the value of the truth itself [Kvanvig] |
Full Idea: The Swamping Problem is that the value of truth swamps the value of additional features of true beliefs which are only instrumentally related to them. True belief is no more valuable if one adds a feature valuable for getting one to the truth. | |
From: Jonathan Kvanvig (Virtue Epistemology [2011], IV B) | |
A reaction: His targets here are reliabilism and epistemic virtues. Kvanvig's implication is that the key to understanding the nature of knowledge is to pinpoint why we value it so much. |
16410 | Extensional semantics has individuals and sets; modal semantics has intensions, functions of world to extension [Stalnaker] |
Full Idea: Semantic values in extensional semantics are extensions, like individuals for terms, and sets for predicates. In modal semantics we have intensions, functions from worlds to appropriate extensions. | |
From: Robert C. Stalnaker (Counterparts and Identity [1987], 2) | |
A reaction: It seems obvious that the meaning of a word like 'giraffe' must include possible giraffes, as well as actual and deceased giraffes. |
11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A. | |
From: Ian Rumfitt ("Yes" and "No" [2000], IV) | |
A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role). |