49 ideas
| 13252 | Some truths have true negations [Beall/Restall] |
| Full Idea: Dialetheism is the view that some truths have true negations. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 7.4) | |
| A reaction: The important thing to remember is that they are truths. Thus 'Are you feeling happy?' might be answered 'Yes and no'. |
| 13247 | A truthmaker is an object which entails a sentence [Beall/Restall] |
| Full Idea: The truthmaker thesis is that an object is a truthmaker for a sentence if and only if its existence entails the sentence. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.5.3) | |
| A reaction: The use of the word 'object' here is even odder than usual, and invites many questions. And the 'only if' seems peculiar, since all sorts of things can make a sentence true. 'There is someone in the house' for example. |
| 13249 | (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall] |
| Full Idea: The inference of 'distribution' (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically. It is straightforward to construct a 'stage' at which the LHS is true but the RHS is not. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 6.1.2) | |
| A reaction: This seems to parallel the iterative notion in set theory, that you must construct your hierarchy. All part of the general 'constructivist' approach to things. Is some kind of mad platonism the only alternative? |
| 13243 | Excluded middle must be true for some situation, not for all situations [Beall/Restall] |
| Full Idea: Relevant logic endorses excluded middle, ..but says instances of the law may fail. Bv¬B is true in every situation that settles the matter of B. It is necessary that there is some such situation. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.2) | |
| A reaction: See next idea for the unusual view of necessity on which this rests. It seems easier to assert something about all situations than just about 'some' situation. |
| 13242 | It's 'relevantly' valid if all those situations make it true [Beall/Restall] |
| Full Idea: The argument from P to A is 'relevantly' valid if and only if, for every situation in which each premise in P is true, so is A. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.2) | |
| A reaction: I like the idea that proper inference should have an element of relevance to it. A falsehood may allow all sorts of things, without actually implying them. 'Situations' sound promising here. |
| 13245 | Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall] |
| Full Idea: Relevant consequence says the conclusion of a relevantly invalid argument is not 'carried in' the premises - it does not follow from the premises. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.3.3) | |
| A reaction: I find this appealing. It need not invalidate classical logic. It is just a tougher criterion which is introduced when you want to do 'proper' reasoning, instead of just playing games with formal systems. |
| 13246 | Relevant logic does not abandon classical logic [Beall/Restall] |
| Full Idea: We have not abandoned classical logic in our acceptance of relevant logic. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.4) | |
| A reaction: It appears that classical logic is straightforwardly accepted, but there is a difference of opinion over when it is applicable. |
| 13254 | A doesn't imply A - that would be circular [Beall/Restall] |
| Full Idea: We could reject the inference from A to itself (on grounds of circularity). | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 8) | |
| A reaction: [Martin-Meyer System] 'It's raining today'. 'Are you implying that it is raining today?' 'No, I'm SAYING it's raining today'. Logicians don't seem to understand the word 'implication'. Logic should capture how we reason. Nice proposal. |
| 13255 | Relevant logic may reject transitivity [Beall/Restall] |
| Full Idea: Some relevant logics reject transitivity, but we defend the classical view. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 8) | |
| A reaction: [they cite Neil Tennant for this view] To reject transitivity (A?B ? B?C ? A?C) certainly seems a long way from classical logic. But in everyday inference Tennant's idea seems good. The first premise may be irrelevant to the final conclusion. |
| 13250 | Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall] |
| Full Idea: A logic is 'free' to the degree it refrains from existential import of its singular and general terms. Classical logic must have non-empty domain, and each name must denote in the domain. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 7.1) | |
| A reaction: My intuition is that logic should have no ontology at all, so I like the sound of 'free' logic. We can't say 'Pegasus does not exist', and then reason about Pegasus just like any other horse. |
| 13235 | Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall] |
| Full Idea: Nowadays we think of the consequence relation itself as the primary subject of logic, and view logical truths as degenerate instances of this relation. Logical truths follow from any set of assumptions, or from no assumptions at all. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.2) | |
| A reaction: This seems exactly right; the alternative is the study of necessities, but that may not involve logic. |
| 13238 | Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall] |
| Full Idea: According to the Peripatetics (Aristotelians), only syllogistic laws stated in variables belong to logic, and not their applications to concrete terms. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.5) | |
| A reaction: [from Lukasiewicz] Seems wrong. I take it there are logical relations between concrete things, and the variables are merely used to describe these relations. Variables lack the internal powers to drive logical necessities. Variables lack essence! |
| 13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |
| Full Idea: Through much of the 20th century the conception of logic was inherited from Frege and Russell, as knowledge of a body of logical truths, as arithmetic or geometry was a knowledge of truths. This is odd, and a historical anomaly. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.2) | |
| A reaction: Interesting. I have always taken this idea to be false. I presume logic has minimal subject matter and truths, and preferably none at all. |
| 13232 | Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall] |
| Full Idea: Logic does not study formal languages for their own sake, which is formal grammar. Logic evaluates arguments, and primarily considers formal languages as interpreted. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.1) | |
| A reaction: Hodges seems to think logic just studies formal languages. The current idea strikes me as a much more sensible view. |
| 13241 | The model theory of classical predicate logic is mathematics [Beall/Restall] |
| Full Idea: The model theory of classical predicate logic is mathematics if anything is. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 4.2.1) | |
| A reaction: This is an interesting contrast to the claim of logicism, that mathematics reduces to logic. This idea explains why students of logic are surprised to find themselves involved in mathematics. |
| 13253 | There are several different consequence relations [Beall/Restall] |
| Full Idea: We are pluralists about logical consequence because we take there to be a number of different consequence relations, each reflecting different precisifications of the pre-theoretic notion of deductive logical consequence. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 8) | |
| A reaction: I don't see how you avoid the slippery slope that leads to daft logical rules like Prior's 'tonk' (from which you can infer anything you like). I say that nature imposes logical conquence on us - but don't ask me to prove it. |
| 13240 | A sentence follows from others if they always model it [Beall/Restall] |
| Full Idea: The sentence X follows logically from the sentences of the class K if and only if every model of the class K is also a model of the sentence X. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 3.2) | |
| A reaction: This why the symbol |= is often referred to as 'models'. |
| 13236 | Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall] |
| Full Idea: If mathematical truth reduces to logical truth then it is important what counts as logically true, …but if logicism is not a going concern, then the body of purely logical truths will be less interesting. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.2) | |
| A reaction: Logicism would only be one motivation for pursuing logical truths. Maybe my new 'Necessitism' will derive the Peano Axioms from broad necessary truths, rather than from logic. |
| 13237 | Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall] |
| Full Idea: The Paradox of the Preface is an apology, that you are committed to each proposition in the book, but admit that collectively they probably contain a mistake. There is a contradiction, of affirming and denying the conjunction of propositions. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.4) | |
| A reaction: This seems similar to the Lottery Paradox - its inverse perhaps. Affirm all and then deny one, or deny all and then affirm one? |
| 17954 | Essence is a thing's necessities, but what about its possibilities (which may not be realised)? [Vetter] |
| Full Idea: Essence is, as it were, necessity rooted in things, ...but how about possibility rooted in things? ...Having the potential to Φ, unlike being essentially Φ, does not entail being actually Φ. | |
| From: Barbara Vetter (Essence and Potentiality [2010], §2) | |
| A reaction: To me this invites the question 'what is it about the entity which endows it with its rooted possibilities?' A thing has possibilities because it has a certain nature (at a given time). |
| 17953 | Real definition fits abstracta, but not individual concrete objects like Socrates [Vetter] |
| Full Idea: I can understand the notion of real definition as applying to (some) abstact entities, but I have no idea how to apply it to a concrete object such as Socrates or myself. | |
| From: Barbara Vetter (Essence and Potentiality [2010], §1) | |
| A reaction: She is objecting to Kit Fine's account of essence, which is meant to be clearer than the normal account of essences based on necessities. Aristotle implies that definitions get fuzzy when you reach the level of the individual. |
| 17952 | Modal accounts make essence less mysterious, by basing them on the clearer necessity [Vetter] |
| Full Idea: The modal account was meant, I take it, to make the notion of essence less mysterious by basing it on the supposedly better understood notion of necessity. | |
| From: Barbara Vetter (Essence and Potentiality [2010], §1) |
| 13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
| Full Idea: In relevant logic, the necessary truths are not those which are true in every situation; rather, they are those for which it is necessary that there is a situation making them true. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.2) | |
| A reaction: This seems to rest on the truthmaker view of such things, which I find quite attractive (despite Merricks's assault). Always ask what is making some truth necessary. This leads you to essences. |
| 17959 | Metaphysical necessity is even more deeply empirical than Kripke has argued [Vetter] |
| Full Idea: We support the views of metaphysical modality on which metaphysical necessity is an even more deeply empirical matter than Kripke has argued. | |
| From: Barbara Vetter (Essence and Potentiality [2010], p.2) | |
| A reaction: [co-author E. Viebahn] This seems to pinpoint the spirit of scientific essentialism. She cites Bird and Shoemaker. If it is empirical, doesn't that make it a matter of epistemology, and hence further from absolute necessity? |
| 17955 | Possible worlds allow us to talk about degrees of possibility [Vetter] |
| Full Idea: The apparatus of possible worlds affords greater expressive power than mere talk of possibility and necessity. In particular, possible worlds talk allows us to introduce degrees of possibility. | |
| From: Barbara Vetter (Essence and Potentiality [2010], §3) | |
| A reaction: A nice feature, but I'm not sure that either the proportion of possible worlds or the closeness of possible worlds captures what we actually mean by a certain degree of possibility. There is 'accidental closeness', or absence of contingency. See Vetter. |
| 17957 | Maybe possibility is constituted by potentiality [Vetter] |
| Full Idea: We should look at the claim that possibility is constituted by potentiality. | |
| From: Barbara Vetter (Essence and Potentiality [2010], §4) | |
| A reaction: A problem that comes to mind is possibilities arising from coincidence. The whole of reality must be described, to capture all the possibilities for a particular thing. So potentialities of what? Nice thought, though. |
| 17958 | The apparently metaphysically possible may only be epistemically possible [Vetter] |
| Full Idea: Some of what metaphysicians take to be metaphysically possible turns out to be only epistemically possible. | |
| From: Barbara Vetter (Essence and Potentiality [2010], §4) | |
| A reaction: A nice clear expression of the increasingly common view that conceivability may be a limited way to grasp possibility. |
| 17956 | Closeness of worlds should be determined by the intrinsic nature of relevant objects [Vetter] |
| Full Idea: The closeness of possible worlds should be determined by similarity in the intrinsic constitution of whatever object it is whose potentialities are at issue. | |
| From: Barbara Vetter (Essence and Potentiality [2010], §3) | |
| A reaction: Nice thought. This seems to be the essentialist approach to possible worlds, but it makes the natures of the objects more fundamental than the framework of the worlds. She demurs because there are also extrinsic potentialities. |
| 13239 | Judgement is always predicating a property of a subject [Beall/Restall] |
| Full Idea: All judgement, for Kant, is essentially the predication of some property to some subject. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.5) | |
| A reaction: Presumably the denial of a predicate could be a judgement, or the affirmation of ambiguous predicates? |
| 13248 | We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall] |
| Full Idea: Situation semantics is a variation of the truth-conditional approach, taking the salient unit of analysis not to be the possible world, or some complete consistent index, but rather the more modest 'situation'. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 5.5.4) | |
| A reaction: When I read Davidson (and implicitly Frege) this is what I always assumed was meant. The idea that worlds are meant has crept in to give truth conditions for modal statements. Hence situation semantics must cover modality. |
| 13233 | Propositions commit to content, and not to any way of spelling it out [Beall/Restall] |
| Full Idea: Our talk of propositions expresses commitment to the general notion of content, without a commitment to any particular way of spelling this out. | |
| From: JC Beall / G Restall (Logical Pluralism [2006], 2.1) | |
| A reaction: As a fan of propositions I like this. It leaves open the question of whether the content belongs to the mind or the language. Animals entertain propositions, say I. |
| 23928 | Good art produces exaltation and detachment [Bell,C] |
| Full Idea: The contemplation of pure form leads to a state of extraordinary exaltation and complete detachment from the concerns of life. | |
| From: Clive Bell (Art [1913], I.III) | |
| A reaction: The last part is what gets the arts a bad name with the people who do deal with the concerns of life (which won't go away, even for an artist!). However, being totally trapped in the concerns of life is probably a recipe for misery. |
| 23922 | The word 'beauty' leads to confusion, because it denotes distinct emotions [Bell,C] |
| Full Idea: The word 'beauty' connotes objects of quite distinguishable emotions, and the term would land me in confusions and misunderstandings. | |
| From: Clive Bell (Art [1913], I.I) | |
| A reaction: His main example is a comparison of beautiful women with beautiful art. Personally I don't think the word aspires to be precise, so there is no problem. Maths has beautiful solutions, golf has beautiful shots, cooking has beautiful results. Wow! |
| 23921 | Our feeling for natural beauty is different from the aesthetic emotion of art [Bell,C] |
| Full Idea: It is not what I call an aesthetic emotion that most of us feel, generally, for natural beauty. …Most people feel a very different kind of emotion for birds, flowers and butterfly wings from that we feel for pictures, pots, temples and statues. | |
| From: Clive Bell (Art [1913], I.I) | |
| A reaction: Not convinced. I think the main difference is our awareness that art is a human production, the result of choice, whereas nature is a given. Beethoven 9 and a good sunset don't seem to me far apart in our responses. |
| 23929 | We only see landscapes as artistic if we ignore their instrumental value [Bell,C] |
| Full Idea: It is only when we cease to regard the objects in a landscape as means to anything that we can feel the landscape artistically. | |
| From: Clive Bell (Art [1913], II.I) | |
| A reaction: This sounds as if only the exploitative attitude blocks the artistic view, but I would expect the scientific view (of an ecologist, for example) to do the same. |
| 23923 | Visual form can create a sublime mental state [Bell,C] |
| Full Idea: Pure visual form transports me to an infinitely sublime state of mind. | |
| From: Clive Bell (Art [1913], I.I) | |
| A reaction: Unusual for anyone to use to term 'sublime' for works of art, and I suspect that Bell was the last to do so. Bell offers a quasi-religious role for art. I accept that being struck by something exceptionally good in art is a very distinctive experience. |
| 23927 | Aestheticism invites artist to create beauty, but with no indication of how to do it [Bell,C] |
| Full Idea: The danger of aestheticism is that the artist who has got nothing to do but make something beautiful hardly knows where to begin or where to end | |
| From: Clive Bell (Art [1913], I.III) | |
| A reaction: Aestheticism strikes me as the main motivation for art nouveau artifacts, which I love. You start with beautiful lines, and then find ways to implement them. Bell has a point, though! |
| 23932 | Art is the expression of an emotion for ultimate reality [Bell,C] |
| Full Idea: My hypothesis is that art is the expression of an emotion for ultimate reality. | |
| From: Clive Bell (Art [1913], II.II) | |
| A reaction: So later in his discussion the word 'ultimate' has crept in, after a chapter about the close relation between religious and artistic attitudes. He also sees good art as deeply 'spiritual'. It seems that religious belief is essential to his theory of art. |
| 8115 | Only artists can discern significant form; other people must look to art to find it [Bell,C, by Gardner] |
| Full Idea: Bell thinks that only artists can discern significant form directly in the natural world, and that all others must look to art for significant form. | |
| From: report of Clive Bell (Art [1913]) by Sebastian Gardner - Aesthetics 3.3 | |
| A reaction: I have a horrible feeling that 'significant' form will turn out to be the sort of form that artists can see. Presumably the form spotted by geologists won't be quite so 'significant'. Not a promising theory. |
| 23924 | Maybe significant form gives us a feeling for ultimate reality [Bell,C] |
| Full Idea: When we strip things of all associations and significance, what is left is 'the thing in itself', or 'ultimate reality'. …Artists can express an emotion felt for reality through line and colour. …So through 'significant form' we sense ultimate reality. | |
| From: Clive Bell (Art [1913], I.III) | |
| A reaction: [compressed] The thing in itself is a Kantian idea. He offers this as a speculation, rather than a fact. Maybe quantum physics gets us closer to the thing in itself? Bell knows that his faith in significant form needs more justification than an emotion. |
| 23931 | Significant form is the essence of art, which I believe expresses an emotion about reality [Bell,C] |
| Full Idea: My view that the essential quality in work of art is significant form was based on experience I am sure about. Of my view that significant form is the expression of a peculiar emotion felt for reality I am far from confident. | |
| From: Clive Bell (Art [1913], II.II) | |
| A reaction: It is hard to understand the idea of 'significant' form without a clear proposal for the nature of the significance. A detective doesn't stop at the point where evidence is seen as significant. Why should a 'peculiar' emotion matter? |
| 20434 | 'Form' is visual relations, and it is 'significant' if it moves us aesthetically; art needs both [Bell,C, by Feagin] |
| Full Idea: By 'form' Bell means the relations of lines, colours and shapes. Forms are 'significant' when the relationships of lines and so on move us aesthetically. If something is art it must have, to at least a minimum extent, significant form. | |
| From: report of Clive Bell (Art [1913], p.17) by Susan Feagin - Roger Fry and Clive Bell 3 | |
| A reaction: So art has two necessary conditions - that it move us aesthetically, and that it does so by means of its form. The obvious problem is to explain which forms are 'significant' without mentioning the aesthetic feeling they have to invoke. |
| 23934 | The only expression art could have is the emotion resulting from pure form [Bell,C] |
| Full Idea: If art expresses anything, it expresses an emotion felt for pure form and that which gives pure form its extraordinary significance. | |
| From: Clive Bell (Art [1913], III.I) | |
| A reaction: I don't think 'expresses' is the right word here. Artists express, but works just transmit. I personally doubt whether anything can have 'extraordinary significance' simply because it expresses one particular emotion. Why art, but not geometry? |
| 23925 | Mere copies of pictures are not significant - unless the copies are very exact [Bell,C] |
| Full Idea: A literal copy is seldom reckoned even by its owner a work of art. Its forms are not significant. Yet if it were an absolutely exact copy, clearly it would be as moving as the original, and a photographic reproduction of a drawing often is. | |
| From: Clive Bell (Art [1913], I.III) | |
| A reaction: What if the original artist made the copy? In 1913, Bell begins to spot this modern problem. He undermines his own theory of significant form here, if the form only becomes significant once we have checked it is an original. |
| 23926 | Art is distinguished by its aesthetic emotion, which produces appropriate form [Bell,C] |
| Full Idea: The characteristic of a work of art is its power of provoking aesthetic emotion; the expression of emotion is what gives it its power. ...Rightness of form is invariably a consequence of rightness of emotion. | |
| From: Clive Bell (Art [1913], I.III) | |
| A reaction: Bell doesn't dig very deep, because the obvious next question, not really addressed, is what makes the emotion 'right'. He suggests that significant form reveals reality, but why would an emotion do that? Does each work have a distinct emotion? |
| 23933 | Aesthetic contemplation is the best and most intense mental state [Bell,C] |
| Full Idea: Art is not only a means to good states of mind, but, perhaps, the best and most potent that we possess; …there is no state of mind more excellent or more intense than the state of aesthetic contemplation. | |
| From: Clive Bell (Art [1913], II.III) | |
| A reaction: Why does intensity make it good? It is pretty intense being involved in a road accident, but that doesn't make it good. There are many states of mind we enjoy or value highly, but we need more than that to prove them objectively 'excellent'. |
| 23935 | Aesthetic experience is an exaltation which increases the possibilities of life [Bell,C] |
| Full Idea: Those who have been thrilled by the pure aesthetic significance of a work of art …carry a state of excitement and exaltation making them more sensitive to all that is going forward about them. Thus they realise …the significance and possibility of life. | |
| From: Clive Bell (Art [1913], IV.III) | |
| A reaction: This seems like a bit of an afterthought, because he struggles to explain why his 'significant form' is so important. He shifts between it being an end - an intrinsic value - or a moral state, or now an increaser of life potential. |
| 22691 | Only artistic qualities matter in art, because they also have the highest moral value [Bell,C] |
| Full Idea: The only relevant qualities in art are artistic qualities: judged as a means to good, no other qualities are worth considering; for there are no qualities of greater moral value than artistic qualities, since there is no greater means to good than art. | |
| From: Clive Bell (Art [1913], II.III) | |
| A reaction: Wishful thinking, I suspect. I can't see anyone acquiring a moral education just by looking a Cezannes. This seems to be a late manifesto for the aesthetic movement. |
| 23930 | Religion sees infinite value in some things, and irrelevance in the rest [Bell,C] |
| Full Idea: The essence of religion is a conviction that because some things are of infinite value most are profoundly unimportant. | |
| From: Clive Bell (Art [1913], II.I) | |
| A reaction: The aspect of religion which most worries atheists like Nietzsche. You can end up with a rather cool and detached view of genocide, if you really believe that worldly matters are unimportant. Do souls in heaven worry about the next life after that? |