43 ideas
| 9408 | Science studies phenomena, but only metaphysics tells us what exists [Mumford] |
| Full Idea: Science deals with the phenomena, ..but it is metaphysics, and only metaphysics, that tells us what ultimately exists. | |
| From: Stephen Mumford (Laws in Nature [2004], 01.2) |
| 9429 | Many forms of reasoning, such as extrapolation and analogy, are useful but deductively invalid [Mumford] |
| Full Idea: There are many forms of reasoning - extrapolation, interpolation, and other arguments from analogy - that are useful but deductively invalid. | |
| From: Stephen Mumford (Laws in Nature [2004], 04.4) | |
| A reaction: [He cites Molnar for this] |
| 10170 | While true-in-a-model seems relative, true-in-all-models seems not to be [Reck/Price] |
| Full Idea: While truth can be defined in a relative way, as truth in one particular model, a non-relative notion of truth is implied, as truth in all models. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: [The article is actually discussing arithmetic] This idea strikes me as extremely important. True-in-all-models is usually taken to be tautological, but it does seem to give a more universal notion of truth. See semantic truth, Tarski, Davidson etc etc. |
| 10166 | ZFC set theory has only 'pure' sets, without 'urelements' [Reck/Price] |
| Full Idea: In standard ZFC ('Zermelo-Fraenkel with Choice') set theory we deal merely with pure sets, not with additional urelements. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §2) | |
| A reaction: The 'urelements' would the actual objects that are members of the sets, be they physical or abstract. This idea is crucial to understanding philosophy of mathematics, and especially logicism. Must the sets exist, just as the urelements do? |
| 10175 | Three types of variable in second-order logic, for objects, functions, and predicates/sets [Reck/Price] |
| Full Idea: In second-order logic there are three kinds of variables, for objects, for functions, and for predicates or sets. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §5) | |
| A reaction: It is interesting that a predicate seems to be the same as a set, which begs rather a lot of questions. For those who dislike second-order logic, there seems nothing instrinsically wicked in having variables ranging over innumerable multi-order types. |
| 10165 | 'Analysis' is the theory of the real numbers [Reck/Price] |
| Full Idea: 'Analysis' is the theory of the real numbers. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §2) | |
| A reaction: 'Analysis' began with the infinitesimal calculus, which later built on the concept of 'limit'. A continuum of numbers seems to be required to make that work. |
| 10174 | Mereological arithmetic needs infinite objects, and function definitions [Reck/Price] |
| Full Idea: The difficulties for a nominalistic mereological approach to arithmetic is that an infinity of physical objects are needed (space-time points? strokes?), and it must define functions, such as 'successor'. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: Many ontologically austere accounts of arithmetic are faced with the problem of infinity. The obvious non-platonist response seems to be a modal or if-then approach. To postulate infinite abstract or physical entities so that we can add 3 and 2 is mad. |
| 10164 | Peano Arithmetic can have three second-order axioms, plus '1' and 'successor' [Reck/Price] |
| Full Idea: A common formulation of Peano Arithmetic uses 2nd-order logic, the constant '1', and a one-place function 's' ('successor'). Three axioms then give '1 is not a successor', 'different numbers have different successors', and induction. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §2) | |
| A reaction: This is 'second-order' Peano Arithmetic, though it is at least as common to formulate in first-order terms (only quantifying over objects, not over properties - as is done here in the induction axiom). I like the use of '1' as basic instead of '0'! |
| 10172 | Set-theory gives a unified and an explicit basis for mathematics [Reck/Price] |
| Full Idea: The merits of basing an account of mathematics on set theory are that it allows for a comprehensive unified treatment of many otherwise separate branches of mathematics, and that all assumption, including existence, are explicit in the axioms. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: I am forming the impression that set-theory provides one rather good model (maybe the best available) for mathematics, but that doesn't mean that mathematics is set-theory. The best map of a landscape isn't a landscape. |
| 10167 | Structuralism emerged from abstract algebra, axioms, and set theory and its structures [Reck/Price] |
| Full Idea: Structuralism has emerged from the development of abstract algebra (such as group theory), the creation of axiom systems, the introduction of set theory, and Bourbaki's encyclopaedic survey of set theoretic structures. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §2) | |
| A reaction: In other words, mathematics has gradually risen from one level of abstraction to the next, so that mathematical entities like points and numbers receive less and less attention, with relationships becoming more prominent. |
| 10169 | Relativist Structuralism just stipulates one successful model as its arithmetic [Reck/Price] |
| Full Idea: Relativist Structuralism simply picks one particular model of axiomatised arithmetic (i.e. one particular interpretation that satisfies the axioms), and then stipulates what the elements, functions and quantifiers refer to. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: The point is that a successful model can be offered, and it doesn't matter which one, like having any sort of aeroplane, as long as it flies. I don't find this approach congenial, though having a model is good. What is the essence of flight? |
| 10179 | There are 'particular' structures, and 'universal' structures (what the former have in common) [Reck/Price] |
| Full Idea: The term 'structure' has two uses in the literature, what can be called 'particular structures' (which are particular relational systems), but also what can be called 'universal structures' - what particular systems share, or what they instantiate. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §6) | |
| A reaction: This is a very helpful distinction, because it clarifies why (rather to my surprise) some structuralists turn out to be platonists in a new guise. Personal my interest in structuralism has been anti-platonist from the start. |
| 10181 | Pattern Structuralism studies what isomorphic arithmetic models have in common [Reck/Price] |
| Full Idea: According to 'pattern' structuralism, what we study are not the various particular isomorphic models of arithmetic, but something in addition to them: a corresponding pattern. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §7) | |
| A reaction: Put like that, we have to feel a temptation to wield Ockham's Razor. It's bad enough trying to give the structure of all the isomorphic models, without seeking an even more abstract account of underlying patterns. But patterns connect to minds.. |
| 10182 | There are Formalist, Relativist, Universalist and Pattern structuralism [Reck/Price] |
| Full Idea: There are four main variants of structuralism in the philosophy of mathematics - formalist structuralism, relativist structuralism, universalist structuralism (with modal variants), and pattern structuralism. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §9) | |
| A reaction: I'm not sure where Chihara's later book fits into this, though it is at the nominalist end of the spectrum. Shapiro and Resnik do patterns (the latter more loosely); Hellman does modal universalism; Quine does the relativist version. Dedekind? |
| 10168 | Formalist Structuralism says the ontology is vacuous, or formal, or inference relations [Reck/Price] |
| Full Idea: Formalist Structuralism endorses structural methodology in mathematics, but rejects semantic and metaphysical problems as either meaningless, or purely formal, or as inference relations. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §3) | |
| A reaction: [very compressed] I find the third option fairly congenial, certainly in preference to rather platonist accounts of structuralism. One still needs to distinguish the mathematical from the non-mathematical in the inference relations. |
| 10178 | Maybe we should talk of an infinity of 'possible' objects, to avoid arithmetic being vacuous [Reck/Price] |
| Full Idea: It is tempting to take a modal turn, and quantify over all possible objects, because if there are only a finite number of actual objects, then there are no models (of the right sort) for Peano Arithmetic, and arithmetic is vacuously true. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §5) | |
| A reaction: [compressed; Geoffrey Hellman is the chief champion of this view] The article asks whether we are not still left with the puzzle of whether infinitely many objects are possible, instead of existent. |
| 10176 | Universalist Structuralism is based on generalised if-then claims, not one particular model [Reck/Price] |
| Full Idea: Universalist Structuralism is a semantic thesis, that an arithmetical statement asserts a universal if-then statement. We build an if-then statement (using quantifiers) into the structure, and we generalise away from any one particular model. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §5) | |
| A reaction: There remains the question of what is distinctively mathematical about the highly generalised network of inferences that is being described. Presumable the axioms capture that, but why those particular axioms? Russell is cited as an originator. |
| 10177 | Universalist Structuralism eliminates the base element, as a variable, which is then quantified out [Reck/Price] |
| Full Idea: Universalist Structuralism is eliminativist about abstract objects, in a distinctive form. Instead of treating the base element (say '1') as an ambiguous referring expression (the Relativist approach), it is a variable which is quantified out. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §5) | |
| A reaction: I am a temperamental eliminativist on this front (and most others) so this is tempting. I am also in love with the concept of a 'variable', which I take to be utterly fundamental to all conceptual thought, even in animals, and not just a trick of algebra. |
| 10171 | The existence of an infinite set is assumed by Relativist Structuralism [Reck/Price] |
| Full Idea: Relativist Structuralism must first assume the existence of an infinite set, otherwise there would be no model to pick, and arithmetical terms would have no reference. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: See Idea 10169 for Relativist Structuralism. They point out that ZFC has an Axiom of Infinity. |
| 9427 | For Humeans the world is a world primarily of events [Mumford] |
| Full Idea: For Humeans the world is a world primarily of events. | |
| From: Stephen Mumford (Laws in Nature [2004], 03.6) |
| 9446 | Properties are just natural clusters of powers [Mumford] |
| Full Idea: The view of properties I find most attractive is one in which they are natural clusters of, and exhausted by, powers (plus other connections to other properties). | |
| From: Stephen Mumford (Laws in Nature [2004], 10.6) |
| 9435 | A 'porridge' nominalist thinks we just divide reality in any way that suits us [Mumford] |
| Full Idea: A 'porridge' nominalist denies natural kinds, and thinks there are no objective divisions in reality, so concepts or words can be used by a community to divide the world up in any way that suits their purposes. | |
| From: Stephen Mumford (Laws in Nature [2004], 07.3) |
| 9447 | If properties are clusters of powers, this can explain why properties resemble in degrees [Mumford] |
| Full Idea: If a cluster of ten powers exhausts property F, and property G differs in respect of just one power, this might explain why properties can resemble other properties and in different degrees. | |
| From: Stephen Mumford (Laws in Nature [2004], 10.6) | |
| A reaction: I love this. The most intractable problem about properties and universals is that of abstract reference - pink resembles red more than pink resembles green. If colours are clusters of powers, red and pink share nine out of ten of them. |
| 10173 | A nominalist might avoid abstract objects by just appealing to mereological sums [Reck/Price] |
| Full Idea: One way for a nominalist to reject appeal to all abstract objects, including sets, is to only appeal to nominalistically acceptable objects, including mereological sums. | |
| From: E Reck / M Price (Structures and Structuralism in Phil of Maths [2000], §4) | |
| A reaction: I'm suddenly thinking that this looks very interesting and might be the way to go. The issue seems to be whether mereological sums should be seen as constrained by nature, or whether they are unrestricted. See Mereology in Ontology...|Intrinsic Identity. |
| 18948 | There is an object for every set of properties (some of which exist, and others don't) [Parsons,T, by Sawyer] |
| Full Idea: According to Terence Parsons, there is an object corresponding to every set of properties. To some of those sets of properties there corresponds an object that exists, and to others there corresponds an object that does not exist (a nonexistent object). | |
| From: report of Terence Parsons (Nonexistent Objects [1980]) by Sarah Sawyer - Empty Names 5 | |
| A reaction: This I take to be the main source of the modern revival of Meinong's notorious view of objects (attacked by Russell). I always find the thought 'a round square is square' to be true, and in need of a truthmaker. But must a round square be non-triangular? |
| 12248 | How can we show that a universally possessed property is an essential property? [Mumford] |
| Full Idea: Essentialists fail to show how we ascend from being a property universally possessed, by all kind members, to the status of being an essential property. | |
| From: Stephen Mumford (Laws in Nature [2004], 07.5) | |
| A reaction: This is precisely where my proposal comes in - the essential properties, as opposed to the accidentaly universals, are those which explain the nature and behaviour of each kind of thing (and each individual thing). |
| 9430 | Singular causes, and identities, might be necessary without falling under a law [Mumford] |
| Full Idea: One might have a singularist view of causation in which a cause necessitates its effect, but they need not be subsumed under a law, ..and there are identities which are metaphysically necessary without being laws of nature. | |
| From: Stephen Mumford (Laws in Nature [2004], 04.5) |
| 9445 | We can give up the counterfactual account if we take causal language at face value [Mumford] |
| Full Idea: If we take causal language at face value and give up reducing causal concepts to non-causal, non-modal concepts, we can give up the counterfactual dependence account. | |
| From: Stephen Mumford (Laws in Nature [2004], 10.5) |
| 9443 | It is only properties which are the source of necessity in the world [Mumford] |
| Full Idea: If laws do not give the world necessity, what does? I argue the positive case for it being properties, and properties alone, that do the job (so we might call them 'modal properties'). | |
| From: Stephen Mumford (Laws in Nature [2004], 10.1) |
| 9444 | There are four candidates for the logical form of law statements [Mumford] |
| Full Idea: The contenders for the logical form of a law statement are 1) a universally quantified conditional, 2) a second-order relation between first-order universals, 3) a functional equivalence, and 4) a dispositional characteristic of a natural kind. | |
| From: Stephen Mumford (Laws in Nature [2004], 10.3) |
| 9431 | Pure regularities are rare, usually only found in idealized conditions [Mumford] |
| Full Idea: Pure regularities are not nearly as common as might have been thought, and are usually only to be found in simplified or idealized conditions. | |
| From: Stephen Mumford (Laws in Nature [2004], 05.3) | |
| A reaction: [He cites Nancy Cartwright 1999 for this view] |
| 9441 | Regularity laws don't explain, because they have no governing role [Mumford] |
| Full Idea: A regularity-law does not explain its instances, because such laws play no role in determining or governing their instances. | |
| From: Stephen Mumford (Laws in Nature [2004], 09.7) | |
| A reaction: Good. It has always seemed to me entirely vacuous to explain an event simply by saying that it falls under some law. |
| 9415 | Would it count as a regularity if the only five As were also B? [Mumford] |
| Full Idea: While it might be true that for all x, if Ax then Bx, would we really want to count it as a genuine regularity in nature if only five things were A (and all five were also B)? | |
| From: Stephen Mumford (Laws in Nature [2004], 03.3) |
| 9416 | Regularities are more likely with few instances, and guaranteed with no instances! [Mumford] |
| Full Idea: It seems that the fewer the instances, the more likely it is that there be a regularity, ..and if there are no cases at all, and no S is P, that is a regularity. | |
| From: Stephen Mumford (Laws in Nature [2004], 03.3) | |
| A reaction: [He attributes the second point to Molnar] |
| 9422 | If the best system describes a nomological system, the laws are in nature, not in the description [Mumford] |
| Full Idea: If the world really does have its own nomological structure, that a systematization merely describes, why are the laws not to be equated with the nomological structure itself, rather than with the system that describes it? | |
| From: Stephen Mumford (Laws in Nature [2004], 03.4) |
| 9421 | The best systems theory says regularities derive from laws, rather than constituting them [Mumford] |
| Full Idea: The best systems theory (of Mill-Ramsey-Lewis) says that laws are not seen as regularities but, rather, as those things from which regularities - or rather, the whole world history including the regularities and everything else - can be derived. | |
| From: Stephen Mumford (Laws in Nature [2004], 03.4) | |
| A reaction: Put this way, the theory invites questions about ontology. Regularities are just patterns in physical reality, but axioms are propositions. So are they just features of human thought, or do these axioms actuallyr reside in reality. Too weak or too strong. |
| 9432 | Laws of nature are necessary relations between universal properties, rather than about particulars [Mumford] |
| Full Idea: The core of the Dretske-Tooley-Armstrong view of the late 70s is that we have a law of nature when we have a relation of natural necessitation between universals. ..The innovation was that laws are about properties, and only indirectly about particulars. | |
| From: Stephen Mumford (Laws in Nature [2004], 06.2) | |
| A reaction: It sounds as if we should then be able to know the laws of nature a priori, since that was Russell's 1912 definition of a priori knowledge. |
| 9433 | If laws can be uninstantiated, this favours the view of them as connecting universals [Mumford] |
| Full Idea: If there are laws that are instantiated in no particulars, then this would seem to favour the theory that laws connect universals rather than particulars. | |
| From: Stephen Mumford (Laws in Nature [2004], 06.4) | |
| A reaction: There is a dispute here between the Platonic view of uninstantiated universals (Tooley) and the Aristotelian instantiated view (Armstrong). Mumford and I prefer the dispositional account. |
| 9434 | Laws of nature are just the possession of essential properties by natural kinds [Mumford] |
| Full Idea: If dispositional essentialism is granted, then there is a law of nature wherever there is an essential property of a natural kind; laws are just the havings of essential properties by natural kinds. | |
| From: Stephen Mumford (Laws in Nature [2004], 07.2) | |
| A reaction: [He is expounding Ellis's view] |
| 9437 | To distinguish accidental from essential properties, we must include possible members of kinds [Mumford] |
| Full Idea: Where properties are possessed by all kind members, we must distinguish the accidental from essential ones by considering all actual and possible kind members. | |
| From: Stephen Mumford (Laws in Nature [2004], 07.5) | |
| A reaction: This is why we must treat possibilities as features of the actual world. |
| 9439 | The Central Dilemma is how to explain an internal or external view of laws which govern [Mumford] |
| Full Idea: The Central Dilemma about laws of nature is that, if they have some governing role, then they must be internal or external to the things governed, and it is hard to give a plausible account of either view. | |
| From: Stephen Mumford (Laws in Nature [2004], 09.2) | |
| A reaction: This dilemma is the basis of Mumford's total rejection of 'laws of nature'. I think I agree. |
| 9412 | You only need laws if you (erroneously) think the world is otherwise inert [Mumford] |
| Full Idea: Laws are a solution to a problem that was misconceived. Only if you think that the world would be otherwise inactive or inanimate, do you have the need to add laws to your ontology. | |
| From: Stephen Mumford (Laws in Nature [2004], 01.5) | |
| A reaction: This is a bold and extreme view - and I agree with it. I consider laws to be quite a useful concept when discussing nature, but they are not part of the ontology, and they don't do any work. They are metaphysically hopeless. |
| 9411 | There are no laws of nature in Aristotle; they became standard with Descartes and Newton [Mumford] |
| Full Idea: Laws do not appear in Aristotle's metaphysics, and it wasn't until Descartes and Newton that laws entered the intellectual mainstream. | |
| From: Stephen Mumford (Laws in Nature [2004], 01.5) | |
| A reaction: Cf. Idea 5470. |