17 ideas
| 12204 | The logic of metaphysical necessity is S5 [Rumfitt] |
| Full Idea: It is a widely accepted thesis that the logic of metaphysical necessity is S5. | |
| From: Ian Rumfitt (Logical Necessity [2010], §5) | |
| A reaction: Rumfitt goes on to defend this standard view (against Dummett's defence of S4). The point, I take it, is that one can only assert that something is 'true in all possible worlds' only when the worlds are all accessible to one another. |
| 12195 | Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt] |
| Full Idea: Our ordinary standards for deeming arguments to be sound vary greatly from context to context. Even the package tourist's syllogism ('It's Tuesday, so this is Belgium') may meet the operative standards for soundness. | |
| From: Ian Rumfitt (Logical Necessity [2010], Intro) | |
| A reaction: No doubt one could spell out the preconceptions of package tourist reasoning, and arrive at the logical form of the implication which is being offered. |
| 12199 | There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt] |
| Full Idea: There is a modal element in consequence, in its applicability to assessing reasoning from suppositions. | |
| From: Ian Rumfitt (Logical Necessity [2010], §2) |
| 12201 | We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt] |
| Full Idea: A rule is to be rejected if it enables us to deduce from some premisses a purported conclusion that does not follow from them in the broad sense. The idea that deductions answer to consequence is incomprehensible if consequence consists in deducibility. | |
| From: Ian Rumfitt (Logical Necessity [2010], §2) |
| 12194 | Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt] |
| Full Idea: Overt contradictions include formal contradictions of form 'B and not B', but I also take them to include 'This is red all over and green all over' and 'This is red and not coloured'. | |
| From: Ian Rumfitt (Logical Necessity [2010], Intro) |
| 12198 | Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt] |
| Full Idea: The geometrical style of formalization of logic is now little more than a quaint anachronism, largely because it fails to show logical truths for what they are: simply by-products of rules of inference that are applicable to suppositions. | |
| From: Ian Rumfitt (Logical Necessity [2010], §1) | |
| A reaction: This is the rejection of Russell-style axiom systems in favour of Gentzen-style natural deduction systems (starting from rules). Rumfitt quotes Dummett in support. |
| 14532 | A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A] |
| Full Idea: Rumfitt argues that there is a distinctive notion of necessity implicated in the notion of logical consequence. | |
| From: report of Ian Rumfitt (Logical Necessity [2010]) by Bob Hale/ Aviv Hoffmann - Introduction to 'Modality' 2 |
| 12193 | Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt] |
| Full Idea: By the notion of 'logical necessity' I mean that there is a sense of 'necessary' for which 'It is necessary that A' implies and is implied by 'It is logically contradictory that not A'. ...From this, logical necessity is implicated in logical consequence. | |
| From: Ian Rumfitt (Logical Necessity [2010], Intro) | |
| A reaction: Rumfitt expresses a commitment to classical logic at this point. We will need to be quite sure what we mean by 'contradiction', which will need a clear notion of 'truth'.... |
| 12200 | A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt] |
| Full Idea: There is no reason to suppose that any statement that is logically necessary (in the present sense) is knowable a priori. ..If a statement is logically necessary, its negation will yield a contradiction, but that does not imply that someone could know it. | |
| From: Ian Rumfitt (Logical Necessity [2010], §2) | |
| A reaction: This remark is aimed at Dorothy Edgington, who holds the opposite view. Rumfitt largely defends McFetridge's view (q.v.). |
| 12202 | Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt] |
| Full Idea: While Fine suggests defining a narrow notion of logical necessity in terms of metaphysical necessity by 'restriction' (to logical truths that can be defined in non-modal terms), this seems unpromising for broad logical necessity, which is modal. | |
| From: Ian Rumfitt (Logical Necessity [2010], §2) | |
| A reaction: [compressed] He cites Kit Fine 2002. Rumfitt glosses the non-modal definitions as purely formal. The metaphysics lurks somewhere in the proof. |
| 12203 | If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt] |
| Full Idea: A world is usually taken to be a fully determinate way that things could have been; but then one might seriously wonder whether anyone is capable of 'considering' such a thing at all. | |
| From: Ian Rumfitt (Logical Necessity [2010], §4) | |
| A reaction: This has always worried me. If I say 'maybe my coat is in the car', I would hate to think that I had to be contemplating some entire possible world (including all the implications of my coat not being on the hat stand). |
| 12163 | Literary meaning emerges in comparisons, and tradition shows which comparisons are relevant [Scruton] |
| Full Idea: We must discover the meanings that emerge when works of literature are experience in relation to each other. ...The importance of tradition is that it denotes - ideally, at least - the class of relevant comparisons. | |
| From: Roger Scruton (Public Text and Common Reader [1982], p.27) | |
| A reaction: This is a nice attempt to explain why we all agree that a thorough education in an art is an essential prerequisite for good taste. Some people (e.g. among the young) seem to have natural good taste. How does that happen? |
| 12162 | In literature, word replacement changes literary meaning [Scruton] |
| Full Idea: In literary contexts semantically equivalent words cannot replace each other without loss of literary meaning. | |
| From: Roger Scruton (Public Text and Common Reader [1982], p.25) | |
| A reaction: The notion of 'literary meaning' is not a standard one, and is questionable whether 'meaning' is the right word, given that a shift in word in a poem is as much to do with sound as with connotations. |
| 12159 | Without intentions we can't perceive sculpture, but that is not the whole story [Scruton] |
| Full Idea: A person for whom it made no difference whether a sculpture was carved by wind and rain or by human hand would be unable to interpret or perceive sculptures - even though the interpretation of sculpture is not the reading of an intention. | |
| From: Roger Scruton (Public Text and Common Reader [1982], p.15) | |
| A reaction: Scruton compares it to the role of intention in language, where there is objective meaning, even though intention is basic to speech. |
| 12160 | In aesthetic interest, even what is true is treated as though it were not [Scruton] |
| Full Idea: In aesthetic interest, even what is true is treated as though it were not. | |
| From: Roger Scruton (Public Text and Common Reader [1982], p.18) | |
| A reaction: A nice aphorism. I always feel uncomfortable reading novels about real people, although the historical Macbeth doesn't bother me much. Novels are too close to reality. Macbeth didn't speak blank verse. |
| 12161 | We can be objective about conventions, but love of art is needed to understand its traditions [Scruton] |
| Full Idea: An historian can elucidate convention while having no feeling for the art that exploits it; whereas an understanding of tradition is reserved for those with the critical insight which comes from the love of art, both past and present. | |
| From: Roger Scruton (Public Text and Common Reader [1982], p.24) | |
| A reaction: This aesthetic observation is obviously close to Scruton's well-known conservatism in politics. I am doubtful whether the notion of 'tradition' can stand up to close examination, though we all know roughly what he means. |
| 20713 | God must be fit for worship, but worship abandons morally autonomy, but there is no God [Rachels, by Davies,B] |
| Full Idea: Rachels argues 1) If any being is God, he must be a fitting object of worship, 2) No being could be a fitting object of worship, since worship requires the abandonment of one's role as an autonomous moral agent, so 3) There cannot be a being who is God. | |
| From: report of James Rachels (God and Human Attributes [1971], 7 p.334) by Brian Davies - Introduction to the Philosophy of Religion 9 'd morality' | |
| A reaction: Presumably Lionel Messi can be a fitting object of worship without being God. Since the problem is with being worshipful, rather than with being God, should I infer that Messi doesn't exist? |