28 ideas
| 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. |
| 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. |
| 19520 | Evidentialism is not axiomatic; the evidence itself inclines us towards evidentialism [Conee] |
| Full Idea: Evidentialism does not support beginning epistemology by taking for granted that evidentialism is true. ...Rather, what potentially justifies belief in intial epistemic data and initial procedures of inquiry is the evidence itself. | |
| From: Earl Conee (First Things First [2004], 'Getting') | |
| A reaction: This sounds good. I much prefer talk of 'evidence' to talk of 'perceptions', because evidence has been licked into shape, and its significance has been clarified. That is the first step towards the coherence we seek. |
| 19521 | If pure guesses were reliable, reliabilists would have to endorse them [Conee] |
| Full Idea: Reliabilism would count pure guesses as good reasons if guessing were properly reliable. | |
| From: Earl Conee (First Things First [2004], 'Getting') | |
| A reaction: See D.H. Lawrence's short story 'The Rocking Horse Winner'. This objection strikes me as being so devastating that it is almost conclusive. Except that pure guesses are never ever reliable, over a decent period of time. |
| 19522 | More than actual reliability is needed, since I may mistakenly doubt what is reliable [Conee] |
| Full Idea: Sheer reliability does not justify belief. ...It may be, for instance, that we have strong though misleading reason to deny the method's reliability. | |
| From: Earl Conee (First Things First [2004], 'Circles') | |
| A reaction: That is, we accept a justification if we judge the method to be reliable, not if it IS reliable. I can disbelieve all the reliable information that arrives in my mind. People do that all the time! Hatred of experts! Support for internalism? |
| 19523 | Reliabilism is poor on reflective judgements about hypothetical cases [Conee] |
| Full Idea: An unrefined reliability theory does a poor job at capturing reflective judgements about hypothetical cases | |
| From: Earl Conee (First Things First [2004], 'Stroud's') | |
| A reaction: Reliability can only be a test for tried and tested ways. No one can say whether imagining a range of possibilities is reliable or not. Is prediction a reliable route to knowledge? |
| 19555 | People begin to doubt whether they 'know' when the answer becomes more significant [Conee] |
| Full Idea: Fluent speakers typically become increasingly hesitant about 'knowledge' attributions as the practical significance of the right answer increases. | |
| From: Earl Conee (Contextualism Contested (and reply) [2005], 'Epistemic') | |
| A reaction: The standard examples of this phenomenon are in criminal investigations, and in philosophical discussions of scepticism. Simple observations I take to have maximum unshakable confidence, except in extreme global scepticism contexts. |
| 19557 | Maybe low knowledge standards are loose talk; people will deny that it is 'really and truly' knowledge [Conee] |
| Full Idea: Maybe variable knowledge ascriptions are just loose talk. This is shown when we ask whether weakly supported knowledge is 'really' or 'truly' or 'really and truly' known. Fluent speakers have a strong inclination to doubt or deny that it is. | |
| From: Earl Conee (Contextualism Contested (and reply) [2005], 'Loose') | |
| A reaction: [bit compressed] Conee is suggesting the people are tacitly invariantist about knowledge (they have a fixed standard). But it may be that someone who asks 'do you really and truly know?' is raising the contextual standard. E.g. a barrister. |
| 19556 | Maybe knowledge has fixed standards (high, but attainable), although people apply contextual standards [Conee] |
| Full Idea: It may be that all 'knowledge' attributions have the same truth conditions, but people apply contextually varying standards. The most plausible standard for truth is very high, but not unreachably high. | |
| From: Earl Conee (Contextualism Contested (and reply) [2005], 'Loose') | |
| A reaction: This is the 'invariantist' alternative to contextualism about knowledge. Is it a standard 'for truth'? Either it is or it isn't true, so there isn't a standard. I take the standard to concern the justification. |
| 12890 | That standards vary with context doesn't imply different truth-conditions for judgements [Conee] |
| Full Idea: The fact that different standards are routinely applied in making an evaluative judgement does not imply the correctness of semantic contextualism about the contents of judgements. ..We can't infer different truth conditions from differing standards. | |
| From: Earl Conee (Contextualism Contested [2005], p.51) | |
| A reaction: This is the basic objection to contextualism from the 'invariantist' camp, which says there are facts about good judgement and justification, despite contextual shifts. My sympathies are with the contextualists (on this one). |
| 12892 | Maybe there is only one context (the 'really and truly' one) for serious discussions of knowledge [Conee] |
| Full Idea: Maybe every issue about knowledge (Gettier problem, scientific knowledge, justification, scepticism) has been discussed solely in the single 'really and truly' context. | |
| From: Earl Conee (Contextualism Contested [2005], p.53) | |
| A reaction: This seems not to be true, if we contrast Descartes' desire for total certainty with Peirce's fallibilism. It seems to me that modern philosophy has deliberately relaxed the standard, in order to make some sort of knowledge possible. Cf. Idea 12894. |
| 7517 | I could take a healthy infant and train it up to be any type of specialist I choose [Watson,JB] |
| Full Idea: Give me a dozen healthy infants, and my own specified world to bring them up in, and I'll guarantee to take any one at random and train him to become any type of specialist I might select - doctor, artist, beggar, thief - regardless of his ancestry. | |
| From: J.B. Watson (Behaviorism [1924], Ch.2), quoted by Steven Pinker - The Blank Slate | |
| A reaction: This was a famous pronouncement rejecting the concept of human nature as in any way fixed - a total assertion of nurture over nature. Modern research seems to be suggesting that Watson is (alas?) wrong. |