49 ideas
| 17774 | Definitions make our intuitions mathematically useful [Mayberry] |
| Full Idea: Definition provides us with the means for converting our intuitions into mathematically usable concepts. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-1) |
| 17773 | Proof shows that it is true, but also why it must be true [Mayberry] |
| Full Idea: When you have proved something you know not only that it is true, but why it must be true. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-2) | |
| A reaction: Note the word 'must'. Presumably both the grounding and the necessitation of the truth are revealed. |
| 17795 | Set theory can't be axiomatic, because it is needed to express the very notion of axiomatisation [Mayberry] |
| Full Idea: Set theory cannot be an axiomatic theory, because the very notion of an axiomatic theory makes no sense without it. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.413-2) | |
| A reaction: This will come as a surprise to Penelope Maddy, who battles with ways to accept the set theory axioms as the foundation of mathematics. Mayberry says that the basic set theory required is much more simple and intuitive. |
| 17796 | There is a semi-categorical axiomatisation of set-theory [Mayberry] |
| Full Idea: We can give a semi-categorical axiomatisation of set-theory (all that remains undetermined is the size of the set of urelements and the length of the sequence of ordinals). The system is second-order in formalisation. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.413-2) | |
| A reaction: I gather this means the models may not be isomorphic to one another (because they differ in size), but can be shown to isomorphic to some third ingredient. I think. Mayberry says this shows there is no such thing as non-Cantorian set theory. |
| 17800 | The misnamed Axiom of Infinity says the natural numbers are finite in size [Mayberry] |
| Full Idea: The (misnamed!) Axiom of Infinity expresses Cantor's fundamental assumption that the species of natural numbers is finite in size. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.414-2) |
| 17801 | The set hierarchy doesn't rely on the dubious notion of 'generating' them [Mayberry] |
| Full Idea: The idea of 'generating' sets is only a metaphor - the existence of the hierarchy is established without appealing to such dubious notions. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.414-2) | |
| A reaction: Presumably there can be a 'dependence' or 'determination' relation which does not involve actual generation. |
| 17803 | Limitation of size is part of the very conception of a set [Mayberry] |
| Full Idea: Our very notion of a set is that of an extensional plurality limited in size. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.415-2) |
| 17786 | The mainstream of modern logic sees it as a branch of mathematics [Mayberry] |
| Full Idea: In the mainstream tradition of modern logic, beginning with Boole, Peirce and Schröder, descending through Löwenheim and Skolem to reach maturity with Tarski and his school ...saw logic as a branch of mathematics. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.410-1) | |
| A reaction: [The lesser tradition, of Frege and Russell, says mathematics is a branch of logic]. Mayberry says the Fregean tradition 'has almost died out'. |
| 17788 | First-order logic only has its main theorems because it is so weak [Mayberry] |
| Full Idea: First-order logic is very weak, but therein lies its strength. Its principle tools (Compactness, Completeness, Löwenheim-Skolem Theorems) can be established only because it is too weak to axiomatize either arithmetic or analysis. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.411-2) | |
| A reaction: He adds the proviso that this is 'unless we are dealing with structures on whose size we have placed an explicit, finite bound' (p.412-1). |
| 17791 | Only second-order logic can capture mathematical structure up to isomorphism [Mayberry] |
| Full Idea: Second-order logic is a powerful tool of definition: by means of it alone we can capture mathematical structure up to isomorphism using simple axiom systems. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1) |
| 17787 | Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry] |
| Full Idea: The 'logica magna' [of the Fregean tradition] has quantifiers ranging over a fixed domain, namely everything there is. In the Boolean tradition the domains differ from interpretation to interpretation. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.410-2) | |
| A reaction: Modal logic displays both approaches, with different systems for global and local domains. |
| 17790 | No Löwenheim-Skolem logic can axiomatise real analysis [Mayberry] |
| Full Idea: No logic which can axiomatize real analysis can have the Löwenheim-Skolem property. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1) |
| 17779 | 'Classificatory' axioms aim at revealing similarity in morphology of structures [Mayberry] |
| Full Idea: The purpose of a 'classificatory' axiomatic theory is to single out an otherwise disparate species of structures by fixing certain features of morphology. ...The aim is to single out common features. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.406-2) |
| 17778 | Axiomatiation relies on isomorphic structures being essentially the same [Mayberry] |
| Full Idea: The central dogma of the axiomatic method is this: isomorphic structures are mathematically indistinguishable in their essential properties. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.406-2) | |
| A reaction: Hence it is not that we have to settle for the success of a system 'up to isomorphism', since that was the original aim. The structures must differ in their non-essential properties, or they would be the same system. |
| 17780 | 'Eliminatory' axioms get rid of traditional ideal and abstract objects [Mayberry] |
| Full Idea: The purpose of what I am calling 'eliminatory' axiomatic theories is precisely to eliminate from mathematics those peculiar ideal and abstract objects that, on the traditional view, constitute its subject matter. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.407-1) | |
| A reaction: A very interesting idea. I have a natural antipathy to 'abstract objects', because they really mess up what could otherwise be a very tidy ontology. What he describes might be better called 'ignoring' axioms. The objects may 'exist', but who cares? |
| 17789 | No logic which can axiomatise arithmetic can be compact or complete [Mayberry] |
| Full Idea: No logic which can axiomatise arithmetic can be compact or complete. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1) | |
| A reaction: I take this to be because there are new truths in the transfinite level (as well as the problem of incompleteness). |
| 17784 | Real numbers can be eliminated, by axiom systems for complete ordered fields [Mayberry] |
| Full Idea: We eliminate the real numbers by giving an axiomatic definition of the species of complete ordered fields. These axioms are categorical (mutually isomorphic), and thus are mathematically indistinguishable. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.408-2) | |
| A reaction: Hence my clever mathematical friend says that it is a terrible misunderstanding to think that mathematics is about numbers. Mayberry says the reals are one ordered field, but mathematics now studies all ordered fields together. |
| 17782 | Greek quantities were concrete, and ratio and proportion were their science [Mayberry] |
| Full Idea: Quantities for Greeks were concrete things - lines, surfaces, solids, times, weights. At the centre of their science of quantity was the beautiful theory of ratio and proportion (...in which the notion of number does not appear!). | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.407-2) | |
| A reaction: [He credits Eudoxus, and cites Book V of Euclid] |
| 17781 | Real numbers were invented, as objects, to simplify and generalise 'quantity' [Mayberry] |
| Full Idea: The abstract objects of modern mathematics, the real numbers, were invented by the mathematicians of the seventeenth century in order to simplify and to generalize the Greek science of quantity. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.407-2) |
| 17799 | Cantor's infinite is an absolute, of all the sets or all the ordinal numbers [Mayberry] |
| Full Idea: In Cantor's new vision, the infinite, the genuine infinite, does not disappear, but presents itself in the guise of the absolute, as manifested in the species of all sets or the species of all ordinal numbers. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.414-2) |
| 17797 | Cantor extended the finite (rather than 'taming the infinite') [Mayberry] |
| Full Idea: We may describe Cantor's achievement by saying, not that he tamed the infinite, but that he extended the finite. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.414-2) |
| 17775 | If proof and definition are central, then mathematics needs and possesses foundations [Mayberry] |
| Full Idea: If we grant, as surely we must, the central importance of proof and definition, then we must also grant that mathematics not only needs, but in fact has, foundations. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-1) |
| 17776 | The ultimate principles and concepts of mathematics are presumed, or grasped directly [Mayberry] |
| Full Idea: The ultimate principles upon which mathematics rests are those to which mathematicians appeal without proof; and the primitive concepts of mathematics ...themselves are grasped directly, if grasped at all, without the mediation of definition. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-1) | |
| A reaction: This begs the question of whether the 'grasping' is purely a priori, or whether it derives from experience. I defend the latter, and Jenkins puts the case well. |
| 17777 | Foundations need concepts, definition rules, premises, and proof rules [Mayberry] |
| Full Idea: An account of the foundations of mathematics must specify four things: the primitive concepts for use in definitions, the rules governing definitions, the ultimate premises of proofs, and rules allowing advance from premises to conclusions. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-2) |
| 17804 | Axiom theories can't give foundations for mathematics - that's using axioms to explain axioms [Mayberry] |
| Full Idea: No axiomatic theory, formal or informal, of first or of higher order can logically play a foundational role in mathematics. ...It is obvious that you cannot use the axiomatic method to explain what the axiomatic method is. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.415-2) |
| 17792 | 1st-order PA is only interesting because of results which use 2nd-order PA [Mayberry] |
| Full Idea: The sole theoretical interest of first-order Peano arithmetic derives from the fact that it is a first-order reduct of a categorical second-order theory. Its axioms can be proved incomplete only because the second-order theory is categorical. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1) |
| 17793 | It is only 2nd-order isomorphism which suggested first-order PA completeness [Mayberry] |
| Full Idea: If we did not know that the second-order axioms characterise the natural numbers up to isomorphism, we should have no reason to suppose, a priori, that first-order Peano Arithmetic should be complete. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1) |
| 17794 | Set theory is not just first-order ZF, because that is inadequate for mathematics [Mayberry] |
| Full Idea: The idea that set theory must simply be identified with first-order Zermelo-Fraenkel is surprisingly widespread. ...The first-order axiomatic theory of sets is clearly inadequate as a foundation of mathematics. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-2) | |
| A reaction: [He is agreeing with a quotation from Skolem]. |
| 17802 | We don't translate mathematics into set theory, because it comes embodied in that way [Mayberry] |
| Full Idea: One does not have to translate 'ordinary' mathematics into the Zermelo-Fraenkel system: ordinary mathematics comes embodied in that system. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.415-1) | |
| A reaction: Mayberry seems to be a particular fan of set theory as spelling out the underlying facts of mathematics, though it has to be second-order. |
| 17805 | Set theory is not just another axiomatised part of mathematics [Mayberry] |
| Full Idea: The fons et origo of all confusion is the view that set theory is just another axiomatic theory and the universe of sets just another mathematical structure. ...The universe of sets ...is the world that all mathematical structures inhabit. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.416-1) |
| 20339 | Classes rarely share properties with their members - unlike universals and types [Wollheim] |
| Full Idea: Classes can share properties with their members (e.g. the class of big things is big), but this is very rare. ....In the case of both universals and types, there will be shared properties. Red things can be exhilarating, and so can redness. | |
| From: Richard Wollheim (Art and Its Objects [1968], 92) | |
| A reaction: 'Exhilarating' is an extrinsic property, so not the best illustration. This is interesting, but would need checking with a wide range of examples. (Too busy for that right now) |
| 17785 | Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry] |
| Full Idea: The abstractness of the old fashioned real numbers has been replaced by generality in the modern theory of complete ordered fields. | |
| From: John Mayberry (What Required for Foundation for Maths? [1994], p.408-2) | |
| A reaction: In philosophy, I'm increasingly thinking that we should talk much more of 'generality', and a great deal less about 'universals'. (By which I don't mean that redness is just the set of red things). |
| 20338 | We often treat a type as if it were a sort of token [Wollheim] |
| Full Idea: Much of the time we think and talk of a type as though it were itself a kind of token. | |
| From: Richard Wollheim (Art and Its Objects [1968], 35) | |
| A reaction: A helpful way of connecting what I call 'objectification' to the more conventional modern philosophical vocabulary. Thus I might claim that beauty is superior to truth, as if they were two tokens. |
| 20342 | Interpretation is performance for some arts, and critical for all arts [Wollheim] |
| Full Idea: Performative interpretation occurs only with certain arts, but critical intepretation pertains to all. | |
| From: Richard Wollheim (Art and Its Objects [1968], 38) | |
| A reaction: Fairly obvious, but this is the first point to make about the concept of 'interpretation'. Does the word in fact have two meanings? Or do I perform a painting when I look carefully at it? |
| 20343 | A love of nature must precede a love of art [Wollheim] |
| Full Idea: We could not have a feeling for the beauties of art unless we had been correspondingly moved in front of nature. | |
| From: Richard Wollheim (Art and Its Objects [1968], 43) | |
| A reaction: Wollheim offers this in defence of Kant's view, without necessarily agreeing. Similarly one could hardly care for fictional characters, but not for real people. So the aesthetic attitude may arise from life, rather than from art. Is art hence unimportant? |
| 20348 | A criterion of identity for works of art would be easier than a definition [Wollheim] |
| Full Idea: Maybe, rather than defining art, it would be more fruitful, and more realistic, to seek a general method of identifying works of art. | |
| From: Richard Wollheim (Art and Its Objects [1968], 60) | |
| A reaction: The whole enterprise is ruined by Marcel Duchamp! I'm more interested in identifying or defining good art. |
| 20347 | If beauty needs organisation, then totally simple things can't be beautiful [Wollheim] |
| Full Idea: It is said that beauty cannot consist in organisation because, if it did, we would not be able to predicate beauty of totally simple objects. | |
| From: Richard Wollheim (Art and Its Objects [1968], 59) | |
| A reaction: [He says this idea originates in Plotinus] I'm struggling to think of an example of something which is 'totally' simple and beautiful. Maybe a patch of colour like the breast of a bullfinch? |
| 20345 | Some say art must have verbalisable expression, and others say the opposite! [Wollheim] |
| Full Idea: The view that a work of art expresses nothing if it can't be put into other words ...is reduced by the view that a work of art has no value if what it expresses or says can be put into (other) words. | |
| From: Richard Wollheim (Art and Its Objects [1968], 49) | |
| A reaction: I prefer the second view. Poetry is what is lost in translation. Good art actually seems to evoke emotions which one virtually never feels in ordinary life. But how could that be possible? What are those emotions doing there? |
| 20331 | It is claimed that the expressive properties of artworks are non-physical [Wollheim] |
| Full Idea: The argument that works of art have properties that physical objects could not have characteristically concentrates on the expressive properties of works of art. | |
| From: Richard Wollheim (Art and Its Objects [1968], 10) | |
| A reaction: Since the idea of an object having non-physical properties strikes me as ridiculous, this gets off to a bad start. If artworks are abstract objects, then all of their properties are non-physical. |
| 20336 | Style can't be seen directly within a work, but appreciation needs a grasp of style [Wollheim] |
| Full Idea: 'Style' would seem to be a concept that cannot be applied to a work solely on the basis of what is represented and yet it is also essential to a proper understanding or appreciation of a work. | |
| From: Richard Wollheim (Art and Its Objects [1968], 32) | |
| A reaction: Sounds right. One long held musical note creates an expectation which depends on the presumed style of the piece of music. A single bar from a piece may well not exhibit its characteristic style. |
| 20337 | The traditional view is that knowledge of its genre to essential to appreciating literature [Wollheim] |
| Full Idea: From Aristotle onwards it has been a tenet of the traditional rhetoric that the proper understanding of a literary work involves the location of it in the correct genre, that is, as drama, epic or lyric. | |
| From: Richard Wollheim (Art and Its Objects [1968], 32) | |
| A reaction: Walton argues this persuasively. I've seen the climax of a Jacobean tragedy ruined by laughter from the audience. Genre dictates appropriate responses, so it is a communal concept. |
| 20333 | If artworks are not physical objects, they are either ideal entities, or collections of phenomena [Wollheim] |
| Full Idea: In denying that works of art are physical objects, one theory (the 'ideal') withdraws them altogether from experience, and a second theory ('phenomenal') pins them too it inescapably and at all points. | |
| From: Richard Wollheim (Art and Its Objects [1968], 21) | |
| A reaction: I incline towards them being transient ideals, created by human minds. As with so much, we idealise and objectify them as 'works', and abstract their image from the instance(s) we encounter. |
| 20334 | The ideal theory says art is an intuition, shaped by a particular process, and presented in public [Wollheim] |
| Full Idea: The ideal theory of Croce and Collingwood says art is first an inner intuition or expression of the artist, resulting from a particular process of organisation and unification, which can be externalised in public form. | |
| From: Richard Wollheim (Art and Its Objects [1968], 22) | |
| A reaction: [compressed] As stated this doesn't sound very controversial or 'ideal'. I take it the theory is intended to be more platonist than this expression of it suggests. I think the idea that it is an 'expression' of the artist is wrong. |
| 20335 | The ideal theory of art neglects both the audience and the medium employed [Wollheim] |
| Full Idea: Because the ideal theory makes a work of art inner or mental, the link between the artist and the audience has been severed .....and it also totally ignores the significance of the medium. | |
| From: Richard Wollheim (Art and Its Objects [1968], 23) | |
| A reaction: Emily Dickinson had virtually no audience for her poetry. The medium used to perform Bach's 'Art of Fugue' seems unimportant. For paintings of painterly painters paint matters. For some visual art many different media will suffice. |
| 20340 | A musical performance has virtually the same features as the piece of music [Wollheim] |
| Full Idea: With the usual reservations, there is nothing that can be predicated of a performance of a piece of music that could not also be predicated of that piece of music itself. | |
| From: Richard Wollheim (Art and Its Objects [1968], 37) | |
| A reaction: He offers this as evidence that it fits the performance being a token, and music (and all other art) being a type. There are quite a few 'reservations'. Music too difficult to perform. Great music always badly performed. |
| 20341 | An interpretation adds further properties to the generic piece of music [Wollheim] |
| Full Idea: Interpretation may be regarded as the production of a token that has properties in excess of those of the type. | |
| From: Richard Wollheim (Art and Its Objects [1968], 37) | |
| A reaction: I suppose so. If you play accurately everything that is written in the score, then anything else has to be an addition. If you play less than the score, you aren't quite playing that piece of music. |
| 20332 | A drawing only represents Napoleon if the artist intended it to [Wollheim] |
| Full Idea: It is necessary, if a drawing is to represent Napoleon, that the draughtsman should intend it to be Napoleon. | |
| From: Richard Wollheim (Art and Its Objects [1968], 13) | |
| A reaction: Does a perfect and intended representation of a person also count as a representation of the person's identical twin? The families of both might well order copies. |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |