37 ideas
18486 | We might define truth as arising from the truth-maker relation [MacBride] |
Full Idea: We might define truth using the truth-maker relation, albeit in a roundabout way, according to the pattern of saying 'S is true' is equivalent to 'there is something which makes S true'. | |
From: Fraser MacBride (Truthmakers [2013], 3.3) | |
A reaction: [MacBride gives it more algebraically, but I prefer English!] You would need to explain 'truth-making' without reference to truth. Horwich objects, reasonably, that ordinary people grasp 'truth' much more clearly than 'truth-making'. Bad idea, I think. |
18484 | Phenomenalists, behaviourists and presentists can't supply credible truth-makers [MacBride] |
Full Idea: For Martin the fatal error of phenomenalists was their inability to supply credible truth-makers for truths about unobserved objects; the same error afflicted Ryle's behaviourism, ...and Prior's Presentism (for past-tensed and future-tensed truths). | |
From: Fraser MacBride (Truthmakers [2013], 3.1) | |
A reaction: This seems to be the original motivation for the modern rise of the truthmaker idea. Personally I find 'Napoleon won at Austerlitz' is a perfectly good past-tensed truthmaker which is compatible with presentism. Truth-making is an excellent challenge. |
18466 | If truthmaking is classical entailment, then anything whatsoever makes a necessary truth [MacBride] |
Full Idea: If a truthmaker entails its truth, this threatens to over-generate truth-makers for necessary truths - at least if the entailment is classical. It's a feature of this notion that anything whatsoever entails a given necessary truth. | |
From: Fraser MacBride (Truthmakers [2013], 1.1) | |
A reaction: This is a good reason to think that the truth-making relation does not consist of logical entailment. |
18473 | 'Maximalism' says every truth has an actual truthmaker [MacBride] |
Full Idea: The principle of 'maximalism' is that for every truth, then there must be something in the world that makes it true. | |
From: Fraser MacBride (Truthmakers [2013], 2.1) | |
A reaction: That seems to mean that no truths can be uttered about anything which is not in the world. If I say 'pigs might have flown', that isn't about the modal profile of actual pigs, it is about what might have resulted from that profile. |
18481 | Maximalism follows Russell, and optimalism (no negative or universal truthmakers) follows Wittgenstein [MacBride] |
Full Idea: If maximalism is intellectual heir to Russell's logical atomism, then 'optimalism' (the denial that universal and negative statements need truth-makers) is heir to Wittgenstein's version, where only atomic propositions represent states of affairs. | |
From: Fraser MacBride (Truthmakers [2013], 2.2) | |
A reaction: Wittgenstein's idea is that you can use the logical connectives to construct all the other universal and negative facts. 'Optimalism' restricts truthmaking to atomic statements. |
18483 | The main idea of truth-making is that what a proposition is about is what matters [MacBride] |
Full Idea: According the Lewis, the kernel of truth in truth-making is the idea that propositions have a subject matter. They are about things, so whether they are true or false depends on how those things stand. | |
From: Fraser MacBride (Truthmakers [2013], 2.4.1) | |
A reaction: [Lewis 'Things Qua Truth-makers' 2003] That sounds like the first step in the story, rather than the 'kernel' of the truth-making approach. |
18477 | There aren't enough positive states out there to support all the negative truths [MacBride] |
Full Idea: It's not obvious that there are enough positive states out there to underwrite all the negative truths. Even though it may be true that this liquid is odourless this needn't be because there's something further about it that excludes its being odourless. | |
From: Fraser MacBride (Truthmakers [2013], 2.1.4.1) | |
A reaction: What is the ontological status of all these hypothetical truths? What is the truthmaker for 'a trillion trillion negative truths exist'? What is the status of 'this is not not-red'? |
18479 | There are different types of truthmakers for different types of negative truth [MacBride] |
Full Idea: We recognise that what makes it true that there is no oil in this engine is different from what makes it true that there are no dodos left. | |
From: Fraser MacBride (Truthmakers [2013], 2.1.4.1) | |
A reaction: This looks like a local particular negation up against a universal negation. I'm not sure there is a big difference between 'my dodo's gone missing' (like my oil), and 'all the dodos have gone permanently missing'. |
18482 | Optimalists say that negative and universal are true 'by default' from the positive truths [MacBride] |
Full Idea: Optimalists say that negative truths are 'true by default' (having the opposite truth value of p), and universal truths are too. Universal truths are equivalent to negative existential truths, which are true by default. | |
From: Fraser MacBride (Truthmakers [2013], 2.2) | |
A reaction: The background idea is Wittgenstein's, that if p is false, then not-p is true by default, without anyone having to assert the negation. This strikes me as a very promising approach to truthmaking. See Simons 2008. |
18485 | Even idealists could accept truthmakers, as mind-dependent [MacBride] |
Full Idea: Even an idealist could accept that there are truth-makers whilst thinking of them as mind-dependent entities. | |
From: Fraser MacBride (Truthmakers [2013], 3.1) | |
A reaction: This undercuts anyone (me, perhaps?) who was hoping to prop up their robust realism with an angry demand to be shown the truthmakers. |
18474 | Does 'this sentence has no truth-maker' have a truth-maker? Reductio suggests it can't have [MacBride] |
Full Idea: If the sentence 'This sentence has no truth-maker' has a truth-maker, then it must be true. But then what it says must be the case, so it has no truth-maker. Hence by reductio the sentence has no truth-maker. | |
From: Fraser MacBride (Truthmakers [2013], 2.1.1) | |
A reaction: [Argument proposed by Peter Milne 2005] Rodriguez-Pereyra replies that the sentence is meaningless, so that it can't possibly be true. The Liar sentence is also said to be meaningless. The argument opposes Maximalism. |
18490 | Maybe 'makes true' is not an active verb, but just a formal connective like 'because'? [MacBride] |
Full Idea: Maybe the truth-maker panegyrists have misconstrued the logical form of 'makes true'. They have taken it to be a verb like 'x hits y', when really it is akin to the connective '→' or 'because'. | |
From: Fraser MacBride (Truthmakers [2013], 3.7) | |
A reaction: [He cites Melia 2005] This isn't any sort of refutation of truth-making, but an offer of how to think of the phenomenon if you reject the big principle. I like truth-making, but resist the 'makes' that brings unthought propositions into existence. |
18493 | Truthmaker talk of 'something' making sentences true, which presupposes objectual quantification [MacBride] |
Full Idea: When supporters of truth-making talk of 'something' which makes a sentence true, they make the assumption that it is an objectual quantifier in name position. | |
From: Fraser MacBride (Truthmakers [2013], 3.8) | |
A reaction: We might say, more concisely, that they are 'reifying' the something. This makes it sound as if Armstrong and Bigelow have made a mistake, but that are simply asserting that this particular quantification is indeed objectual. |
12452 | Our dislike of contradiction in logic is a matter of psychology, not mathematics [Brouwer] |
Full Idea: Not to the mathematician, but to the psychologist, belongs the task of explaining why ...we are averse to so-called contradictory systems in which the negative as well as the positive of certain propositions are valid. | |
From: Luitzen E.J. Brouwer (Intuitionism and Formalism [1912], p.79) | |
A reaction: Was the turning point of Graham Priest's life the day he read this sentence? I don't agree. I take the principle of non-contradiction to be a highly generalised observation of how the world works (and Russell agrees with me). |
15941 | For intuitionists excluded middle is an outdated historical convention [Brouwer] |
Full Idea: From the intuitionist standpoint the dogma of the universal validity of the principle of excluded third in mathematics can only be considered as a phenomenon of history of civilization, like the rationality of pi or rotation of the sky about the earth. | |
From: Luitzen E.J. Brouwer (works [1930]), quoted by Shaughan Lavine - Understanding the Infinite VI.2 | |
A reaction: [Brouwer 1952:510-11] |
18489 | Connectives link sentences without linking their meanings [MacBride] |
Full Idea: The 'connectives' are expressions that link sentences but without expressing a relation that holds between the states of affairs, facts or tropes that these sentences denote. | |
From: Fraser MacBride (Truthmakers [2013], 3.7) | |
A reaction: MacBride notes that these contrast with ordinary verbs, which do express meaningful relations. |
18476 | 'A is F' may not be positive ('is dead'), and 'A is not-F' may not be negative ('is not blind') [MacBride] |
Full Idea: Statements of the form 'a is F' aren't invariably positive ('a is dead'), and nor are statements of the form 'a isn't F' ('a isn't blind') always negative. | |
From: Fraser MacBride (Truthmakers [2013], 2.1.4) | |
A reaction: The point is that the negation may be implicit in the predicate. There are many ways to affirm or deny something, other than by use of the standard syntax. |
18119 | Mathematics is a mental activity which does not use language [Brouwer, by Bostock] |
Full Idea: Brouwer made the rather extraordinary claim that mathematics is a mental activity which uses no language. | |
From: report of Luitzen E.J. Brouwer (Mathematics, Science and Language [1928]) by David Bostock - Philosophy of Mathematics 7.1 | |
A reaction: Since I take language to have far less of a role in thought than is commonly believed, I don't think this idea is absurd. I would say that we don't use language much when we are talking! |
8923 | Numbers are identified by their main properties and relations, involving the successor function [MacBride] |
Full Idea: The mathematically significant properties and relations of natural numbers arise from the successor function that orders them; the natural numbers are identified simply as the objects that answer to this basic function. | |
From: Fraser MacBride (Structuralism Reconsidered [2007], §1) | |
A reaction: So Julius Caesar would be a number if he was the successor of Pompey the Great? I would have thought that counting should be mentioned - cardinality as well as ordinality. Presumably Peano's Axioms are being referred to. |
18247 | Brouwer saw reals as potential, not actual, and produced by a rule, or a choice [Brouwer, by Shapiro] |
Full Idea: In his early writing, Brouwer took a real number to be a Cauchy sequence determined by a rule. Later he augmented rule-governed sequences with free-choice sequences, but even then the attitude is that Cauchy sequences are potential, not actual infinities. | |
From: report of Luitzen E.J. Brouwer (works [1930]) by Stewart Shapiro - Philosophy of Mathematics 6.6 | |
A reaction: This is the 'constructivist' view of numbers, as espoused by intuitionists like Brouwer. |
12451 | Scientific laws largely rest on the results of counting and measuring [Brouwer] |
Full Idea: A large part of the natural laws introduced by science treat only of the mutual relations between the results of counting and measuring. | |
From: Luitzen E.J. Brouwer (Intuitionism and Formalism [1912], p.77) | |
A reaction: His point, I take it, is that the higher reaches of numbers have lost touch with the original point of the system. I now see the whole issue as just depending on conventions about the agreed extension of the word 'number'. |
18118 | Brouwer regards the application of mathematics to the world as somehow 'wicked' [Brouwer, by Bostock] |
Full Idea: Brouwer regards as somehow 'wicked' the idea that mathematics can be applied to a non-mental subject matter, the physical world, and that it might develop in response to the needs which that application reveals. | |
From: report of Luitzen E.J. Brouwer (Mathematics, Science and Language [1928]) by David Bostock - Philosophy of Mathematics 7.1 | |
A reaction: The idea is that mathematics only concerns creations of the human mind. It presumably has no more application than, say, noughts-and-crosses. |
8926 | For mathematical objects to be positions, positions themselves must exist first [MacBride] |
Full Idea: The identification of mathematical objects with positions in structures rests upon the prior credibility of the thesis that positions are objects in their own right. | |
From: Fraser MacBride (Structuralism Reconsidered [2007], §3) | |
A reaction: Sounds devastating, but something has to get the whole thing off the ground. This is why Resnik's word 'patterns' is so appealing. Patterns stare you in the face, and they don't change if all the objects making it up are replaced by others. |
12454 | Intuitionists only accept denumerable sets [Brouwer] |
Full Idea: The intuitionist recognises only the existence of denumerable sets. | |
From: Luitzen E.J. Brouwer (Intuitionism and Formalism [1912], p.80) | |
A reaction: That takes you up to omega, but not beyond, presumably because it then loses sight of the original intuition of 'bare two-oneness' (Idea 12453). I sympathise, but the word 'number' has shifted its meaning a lot these days. |
12453 | Neo-intuitionism abstracts from the reuniting of moments, to intuit bare two-oneness [Brouwer] |
Full Idea: Neo-intuitionism sees the falling apart of moments, reunited while remaining separated in time, as the fundamental phenomenon of human intellect, passing by abstracting to mathematical thinking, the intuition of bare two-oneness. | |
From: Luitzen E.J. Brouwer (Intuitionism and Formalism [1912], p.80) | |
A reaction: [compressed] A famous and somewhat obscure idea. He goes on to say that this creates one and two, and all the finite ordinals. |
8728 | Intuitionist mathematics deduces by introspective construction, and rejects unknown truths [Brouwer] |
Full Idea: Mathematics rigorously treated from the point of view of deducing theorems exclusively by means of introspective construction, is called intuitionistic mathematics. It deviates from classical mathematics, which believes in unknown truths. | |
From: Luitzen E.J. Brouwer (Consciousness, Philosophy and Mathematics [1948]), quoted by Stewart Shapiro - Thinking About Mathematics 1.2 | |
A reaction: Clearly intuitionist mathematics is a close cousin of logical positivism and the verification principle. This view would be anathema to Frege, because it is psychological. Personally I believe in the existence of unknown truths, big time! |
18480 | Maybe it only exists if it is a truthmaker (rather than the value of a variable)? [MacBride] |
Full Idea: 'To be is to be a truth-maker' has been proposed as a replacement the standard conception of ontological commitment, that to be is to be the value of a variable. | |
From: Fraser MacBride (Truthmakers [2013], 2.1.4.2) | |
A reaction: [He cites Ross Cameron 2008] Unconvincing. What does it mean to say that some remote unexperienced bit of the universe 'makes truths'? How many truths? Where do these truths reside when they aren't doing anything useful? |
18471 | Different types of 'grounding' seem to have no more than a family resemblance relation [MacBride] |
Full Idea: The concept of 'grounding' appears to cry out for treatment as a family resemblance concept, a concept whose instances have no more in common than different games do. | |
From: Fraser MacBride (Truthmakers [2013], 1.6) | |
A reaction: I like the word 'determinations', though MacBride's point my also apply to that. I take causation to be one species of determination, and truth-making to be another. They form a real family, with no adoptees. |
18472 | Which has priority - 'grounding' or 'truth-making'? [MacBride] |
Full Idea: Some philosophers define 'grounding' in terms of 'truth-making', rather than the other way around. | |
From: Fraser MacBride (Truthmakers [2013], 1.6) | |
A reaction: [Cameron exemplifies the first, and Schaffer the second] I would have thought that grounding was in the world, but truth-making required the introduction of propositions about the world by minds, so grounding is prior. Schaffer is right. |
18475 | Russell allows some complex facts, but Wittgenstein only allows atomic facts [MacBride] |
Full Idea: The logical atomism of Russell admitted some logically complex facts but not others - in contrast to Wittgenstein's version which admitted only atomic facts. | |
From: Fraser MacBride (Truthmakers [2013], 2.1.3) | |
A reaction: For truthmakers, it looks as if the Wittgenstein version might do a better job (e.g. with negative truths). I quite like the Russell approach, where complex facts underwrite the logical connectives. Disjunctive, negative, conjunctive, hypothetical facts. |
21354 | It may be that internal relations like proportion exist, because we directly perceive it [MacBride] |
Full Idea: Some philosophers maintain that we literally perceive proportions and other internal relations. These relations must exist, otherwise we couldn't perceive them. | |
From: Fraser MacBride (Relations [2016], 3) | |
A reaction: [He cites Mulligan 1991, and Hochberg 2013:232] This seems a rather good point. You can't perceive the differing heights of two people, yet fail to perceive that one is taller. You also perceive 'below', which is external. |
21353 | Internal relations are fixed by existences, or characters, or supervenience on characters [MacBride] |
Full Idea: Internal relations are determined either by the mere existence of the things they relate, or by their intrinsic characters, or they supervene on the intrinsic characters of the things they relate. | |
From: Fraser MacBride (Relations [2016], 3) | |
A reaction: Suggesting that they 'supervene' doesn't explain anything (and supervenience never explains anything). I vote for the middle one - the intrinsic character. It has to be something about the existence, and not the mere fact of existence. |
21352 | 'Multigrade' relations are those lacking a fixed number of relata [MacBride] |
Full Idea: A 'unigrade' relation R has a definite degree or adicity: R is binary, or ternary....or n-ary (for some unique n). By contrast a relation is 'multigrade' if it fails to be unigrade. Causation appears to be multigrade. | |
From: Fraser MacBride (Relations [2016], 1) | |
A reaction: He also cites entailment, which may have any number of premises. |
18435 | Resemblance Nominalists say that resemblance explains properties (not the other way round) [Rodriquez-Pereyra] |
Full Idea: Resemblance Nominalists cannot explain the resemblance between particulars in terms of their properties, because they explain particulars' properties in terms of their resemblances. | |
From: Gonzalo Rodriguez-Pereyra (Resemblance Nominalism and Russell's Regress [2001], p.397), quoted by Douglas Edwards - Properties 5.5.1 | |
A reaction: While resemblance does seem to be a primitive fact of experience, and it points us towards the properties, to say that resemblance explains properties is obviously (as so often...) getting things the wrong way round. Properties ARE resemblances?? |
18436 | Entities are truthmakers for their resemblances, so no extra entities or 'resemblances' are needed [Rodriquez-Pereyra] |
Full Idea: A and B are the sole truthmakers for 'A and B resemble each other'. There is no need to postulate extra entities - the resembling entities suffice to account for them. There is no regress of resemblances, ...since there are no resemblances at all. | |
From: Gonzalo Rodriguez-Pereyra (Resemblance Nominalism: a solution to universals [2002], p.115), quoted by Douglas Edwards - Properties 5.5.2 | |
A reaction: This seems to flatly reject the ordinary conversational move of asking in what 'respect' the two things resemble, which may be a genuine puzzle which gets an illuminating answer. We can't fully explain resemblance, but we can do better than this! |
18478 | Wittgenstein's plan to show there is only logical necessity failed, because of colours [MacBride] |
Full Idea: It is almost universally acknowledged that Wittgenstein's plan to show all necessity is logical necessity ended in failure - indeed foundered upon the very problem of explaining colour incompatibilities. | |
From: Fraser MacBride (Truthmakers [2013], 2.1.4.1) | |
A reaction: I'm not sure whether you can 'show' that colour incompatibility is some sort of necessity, though intuitively it seems so. I'm thinking that 'necessity' is a unitary concept, with a wide variety of sources generating it. |
10117 | Intuitonists in mathematics worried about unjustified assertion, as well as contradiction [Brouwer, by George/Velleman] |
Full Idea: The concern of mathematical intuitionists was that the use of certain forms of inference generates, not contradiction, but unjustified assertions. | |
From: report of Luitzen E.J. Brouwer (Intuitionism and Formalism [1912]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.6 | |
A reaction: This seems to be the real origin of the verificationist idea in the theory of meaning. It is a hugely revolutionary idea - that ideas are not only ruled out of court by contradiction, but that there are other criteria which should also be met. |