35 ideas
| 19306 | It is a principle of reasoning not to clutter your mind with trivialities [Harman] |
| Full Idea: I am assuming the following principle: Clutter Avoidance - in reasoning, one should not clutter one's mind with trivialities. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 2) | |
| A reaction: I like Harman's interest in the psychology of reasoning. In the world of Frege, it is taboo to talk about psychology. |
| 19304 | The rules of reasoning are not the rules of logic [Harman] |
| Full Idea: Rules of deduction are rules of deductive argument; they are not rules of inference or reasoning. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 1) | |
| A reaction: And I have often noticed that good philosophing reasoners and good logicians are frequently not the same people. |
| 19307 | If there is a great cost to avoiding inconsistency, we learn to reason our way around it [Harman] |
| Full Idea: We sometimes discover our views are inconsistent and do not know how to revise them in order to avoid inconsistency without great cost. The best response may be to keep the inconsistency and try to avoid inferences that exploit it. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 2) | |
| A reaction: Any decent philosopher should face this dilemma regularly. I assume non-philosophers don't compare the different compartments of their beliefs very much. Students of non-monotonic logics are trying to formalise such thinking. |
| 19309 | Logic has little relevance to reasoning, except when logical conclusions are immediate [Harman] |
| Full Idea: Although logic does not seem specially relevant to reasoning, immediate implication and immediate inconsistency do seem important for reasoning. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 2) | |
| A reaction: Ordinary thinkers can't possibly track complex logical implications, so we have obviously developed strategies for coping. I assume formal logic is contructed from the basic ingredients of the immediate and obvious implications, such as modus ponens. |
| 19303 | Implication just accumulates conclusions, but inference may also revise our views [Harman] |
| Full Idea: Implication is cumulative, in a way that inference may not be. In argument one accumulates conclusions; things are always added, never subtracted. Reasoned revision, however, can subtract from one's view as well as add. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 1) | |
| A reaction: This has caught Harman's attention, I think (?), because he is looking for non-monotonic reasoning (i.e. revisable reasoning) within a classical framework. If revision is responding to evidence, the logic can remain conventional. |
| 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. |
| 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'. |
| 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'? |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 19305 | The Gambler's Fallacy (ten blacks, so red is due) overemphasises the early part of a sequence [Harman] |
| Full Idea: The Gambler's Fallacy says if black has come up ten times in a row, red must be highly probable next time. It overlooks how the impact of an initial run of one color can become more and more insignificant as the sequence gets longer. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 1) | |
| A reaction: At what point do you decide that the roulette wheel is fixed, rather than that you have fallen for the Gambler's Fallacy? Interestingly, standard induction points to the opposite conclusion. But then you have prior knowledge of the wheel. |
| 19310 | High probability premises need not imply high probability conclusions [Harman] |
| Full Idea: Propositions that are individually highly probable can have an immediate implication that is not. The fact that one can assign a high probability to P and also to 'if P then Q' is not sufficient reason to assign high probability to Q. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 3) | |
| A reaction: He cites Kyburg's Lottery Paradox. It is probable that there is a winning ticket, and that this ticket is not it. Thus it is NOT probable that I will win. |
| 19308 | We strongly desire to believe what is true, even though logic does not require it [Harman] |
| Full Idea: Moore's Paradox: one is strongly disposed not to believe both P and that one does not believe that P, while realising that these propositions are perfectly consistent with one another. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 2) | |
| A reaction: [Where in Moore?] A very nice example of a powerful principle of reasoning which can never be captured in logic. |
| 19311 | In revision of belief, we need to keep track of justifications for foundations, but not for coherence [Harman] |
| Full Idea: The key issue in belief revision is whether one needs to keep track of one's original justifications for beliefs. What I am calling the 'foundations' theory says yes; what I am calling the 'coherence' theory says no. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 4) | |
| A reaction: I favour coherence in all things epistemological, and this idea seems to match real life, where I am very confident of many beliefs of which I have forgotten the justification. Harman says coherentists need the justification only when they doubt a belief. |
| 19312 | Coherence is intelligible connections, especially one element explaining another [Harman] |
| Full Idea: Coherence in a view consists in connections of intelligibility among the elements of the view. Among other things these included explanatory connections, which hold when part of one's view makes it intelligible why some other part should be true. | |
| From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 7) | |
| A reaction: Music to my ears. I call myself an 'explanatory empiricist', and embrace a coherence theory of justification. This is the framework within which philosophy should be practised. Harman is our founder, and Paul Thagard our guru. |
| 6613 | The natural kinds are objects, processes and properties/relations [Ellis] |
| Full Idea: There are three hierarchies of natural kinds: objects or substances (substantive universals), events or processes (dynamic universals), and properties or relations (tropic universals). | |
| From: Brian Ellis (Katzav on limitations of dispositions [2005], 91) | |
| A reaction: Most interesting here is the identifying of natural kinds with universals, making universals into the families of nature. Universals are high-level sets of natural kinds. To grasp universals you must see patterns, and infer the underlying order. |
| 6616 | Least action is not a causal law, but a 'global law', describing a global essence [Ellis] |
| Full Idea: The principle of least action is not a causal law, but is what I call a 'global law', which describes the essence of the global kind, which every object in the universe necessarily instantiates. | |
| From: Brian Ellis (Katzav on limitations of dispositions [2005]) | |
| A reaction: As a fan of essentialism I find this persuasive. If I inherit part of my essence from being a mammal, I inherit other parts of my essence from being an object, and all objects would share that essence, so it would look like a 'law' for all objects. |
| 6615 | A species requires a genus, and its essence includes the essence of the genus [Ellis] |
| Full Idea: A specific universal can exist only if the generic universal of which it is a species exists, but generic universals don't depend on species; …the essence of any genus is included in its species, but not conversely. | |
| From: Brian Ellis (Katzav on limitations of dispositions [2005], 91) | |
| A reaction: Thus the species 'electron' would be part of the genus 'lepton', or 'human' part of 'mammal'. The point of all this is to show how individual items connect up with the rest of the universe, giving rise to universal laws, such as Least Action. |
| 6614 | A hierarchy of natural kinds is elaborate ontology, but needed to explain natural laws [Ellis] |
| Full Idea: The hierarchy of natural kinds proposed by essentialism may be more elaborate than is strictly required for purposes of ontology, but it is necessary to explain the necessity of the laws of nature, and the universal applicability of global principles. | |
| From: Brian Ellis (Katzav on limitations of dispositions [2005], 91) | |
| A reaction: I am all in favour of elaborating ontology in the name of best explanation. There seem, though, to be some remaining ontological questions at the point where the explanations of essentialism run out. |
| 6612 | Without general principles, we couldn't predict the behaviour of dispositional properties [Ellis] |
| Full Idea: It is objected to dispositionalism that without the principle of least action, or some general principle of equal power, the specific dispositional properties of things could tell us very little about how these things would be disposed to behave. | |
| From: Brian Ellis (Katzav on limitations of dispositions [2005], 90) | |
| A reaction: Ellis attempts to meet this criticism, by placing dispositional properties within a hierarchy of broader properties. There remains a nagging doubt about how essentialism can account for space, time, order, and the existence of essences. |