44 ideas
| 14415 | A ground must be about its truth, and not just necessitate it [Merricks] |
| Full Idea: A ground does not merely necessitate its truth. A ground is also what its truth is appropriately about. | |
| From: Trenton Merricks (Truth and Ontology [2007], 7.II) |
| 14408 | Truthmaker needs truths to be 'about' something, and that is often unclear [Merricks] |
| Full Idea: It is not always obvious what (if anything) a truth is about, in the sense of 'about' relevant to Truthmaker and truth-supervenient-on-being. Prior says 'Queen Anne is dead' is not about Queen Anne, and may be about the Earth. | |
| From: Trenton Merricks (Truth and Ontology [2007], 6.III) | |
| A reaction: A very nice and rather subtle objection to the Truthmaker thesis. Specifying the truthmaker for a given truth looks like a doddle in simple cases, but clearly it can become extremely elusive in other cases. |
| 14395 | If a ball changes from red to white, Truthmaker says some thing must make the change true [Merricks] |
| Full Idea: If a single ball goes from being red to being white, Truthmaker implies that something exists which makes it true that the second thing follows the first. | |
| From: Trenton Merricks (Truth and Ontology [2007], 3.V) |
| 14398 | Truthmaker says if an entity is removed, some nonexistence truthmaker must replace it [Merricks] |
| Full Idea: Truthmaker makes it impossible simply to remove an entity. One must always replace it with something else; namely, a truthmaker for the claim that that entity does not exist. | |
| From: Trenton Merricks (Truth and Ontology [2007], 4.I-3) | |
| A reaction: This is a particularly strong and persuasive argument from Merricks against the truthmaker view. Clearly the truthmaker for non-existence can't be there when it exists, and the destruction bringing the negative truthmaker into existence sounds odd. |
| 14403 | If Truthmaker says each truth is made by the existence of something, the theory had de re modality at is core [Merricks] |
| Full Idea: Truthmaker says that, for each truth, there is something that, by its mere existence, makes that truth true, …so Truthmaker has de re modality at its core. | |
| From: Trenton Merricks (Truth and Ontology [2007], 5.III) | |
| A reaction: I have no problem with de re modality, so this doesn't bother me. Merricks brings out nicely the baggage which you must carry if you are a Truthmaker. |
| 14397 | Truthmaker demands not just a predication, but an existing state of affairs with essential ingredients [Merricks] |
| Full Idea: The claim 'that Fido is brown' seems to demand only a brown Fido, but Truthmaker demands more. It demands both that a state of affairs along the lines of 'Fido's being brown' exists, and also that this state has its constituents essentially. | |
| From: Trenton Merricks (Truth and Ontology [2007], 4.I) | |
| A reaction: One would need to reread Merricks to get this clear, but my instinct is that the two scenarios are not very different. 'A brown Fido' would require Fido to be necessarily brown to do the job. |
| 14396 | If 'truth supervenes on being', worlds with the same entities, properties and relations have the same truths [Merricks] |
| Full Idea: 'Truth supervenes on being' says that any two possible worlds alike with respect to what entities exist and which properties (and relations) each of those entities exemplifies are thereby alike with respect to what is true. | |
| From: Trenton Merricks (Truth and Ontology [2007], 4) | |
| A reaction: Merricks says this view is found in early Wittgenstein, as well as in David Lewis. He suggests that this is a weaker and more plausible thesis than the full commitment to truthmakers. It still allows some truths to lack truthmakers. Sounds plausible. |
| 14400 | If truth supervenes on being, that won't explain why truth depends on being [Merricks] |
| Full Idea: If 'truth supervenes on being' aims to articulate the idea that truth depends on being, it must say more than that truth supervenes on being. | |
| From: Trenton Merricks (Truth and Ontology [2007], 4.VI) | |
| A reaction: This is a perennial problem with supervenience accounts, such as the supervenience of beauty on the object, or of mind on brain. |
| 14394 | It is implausible that claims about non-existence are about existing things [Merricks] |
| Full Idea: It is implausible that a claim asserting that a thing fails to exist is made true by - and so is appropriately about - some other, existing thing. | |
| From: Trenton Merricks (Truth and Ontology [2007], 3.V) |
| 14390 | Truthmaker isn't the correspondence theory, because it offers no analysis of truth [Merricks] |
| Full Idea: Because Truthmaker offers no analysis of being true, Truthmaker is not the correspondence theory of truth. | |
| From: Trenton Merricks (Truth and Ontology [2007], 1.IV) | |
| A reaction: I'm not convinced that the correspondence theory offers an 'analysis' of truth. It doesn't seem to do much more than offer a word which suggests an analogy with some relation in the world. |
| 14412 | Speculations about non-existent things are not about existent things, so Truthmaker is false [Merricks] |
| Full Idea: That 'there might have been a dozen more fundamental particles' is true, but not appropriately about any existing entities or their properties. Since Truthmaker says that all truths are about existing entities, it must be false. | |
| From: Trenton Merricks (Truth and Ontology [2007], 6.VI) | |
| A reaction: Since I don't necessarily agree that 'there might have been a dozen more fundamental particles' (see Scientific Essentialism), and I take the disagreement to have some basis, I doubt this idea. What stops 'there could be circular squares' from being true? |
| 14414 | I am a truthmaker for 'that a human exists', but is it about me? [Merricks] |
| Full Idea: I am a truthmaker for 'that a human exists', but it is not obvious that that proposition is thus about me. | |
| From: Trenton Merricks (Truth and Ontology [2007], 7.I) | |
| A reaction: This is part of the general rather good objection that it is often unclear what a truth is 'about' (Idea 14408). The original Gettier examples about justification illustrate this problem. They make things true, in a surprising way. |
| 14391 | If the correspondence theory is right, then necessary truths must correspond to something [Merricks] |
| Full Idea: Suppose for the sake of argument that the correspondence theory is correct. Then it is analytic that each necessary truth, in virtue of being true, corresponds to something. | |
| From: Trenton Merricks (Truth and Ontology [2007], 2.II) | |
| A reaction: The sort of nice simple observation for which I admire Merricks. You don't have to give up on the correspondence theory at this point, but you will have to go through with some substantial metaphysics to keep it afloat. |
| 14418 | Being true is not a relation, it is a primitive monadic property [Merricks] |
| Full Idea: Being true is not a relation. …Being true is a monadic property. …Being true is a primitive property. | |
| From: Trenton Merricks (Truth and Ontology [2007], 8.IV) | |
| A reaction: Even after reading Merricks on this, I am not sure I understand it. If a single sentence floats in the void, it is hard to see how the 'monadic' property of truth could accrue to it. |
| 14419 | Deflationism just says there is no property of being truth [Merricks] |
| Full Idea: I take 'deflationism' to be nothing other than the claim that there is no property of being true. | |
| From: Trenton Merricks (Truth and Ontology [2007], 8.V) |
| 10775 | The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp] |
| Full Idea: The main objection to the axiom of choice was that it had to be given by some law or definition, but since sets are arbitrary this seems irrelevant. Formalists consider it meaningless, but set-theorists consider it as true, and practically obvious. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §3) |
| 10766 | Logic is either for demonstration, or for characterizing structures [Tharp] |
| Full Idea: One can distinguish at least two quite different senses of logic: as an instrument of demonstration, and perhaps as an instrument for the characterization of structures. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
| A reaction: This is trying to capture the proof-theory and semantic aspects, but merely 'characterizing' something sounds like a rather feeble aspiration for the semantic side of things. Isn't it to do with truth, rather than just rule-following? |
| 10767 | Elementary logic is complete, but cannot capture mathematics [Tharp] |
| Full Idea: Elementary logic cannot characterize the usual mathematical structures, but seems to be distinguished by its completeness. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10769 | Second-order logic isn't provable, but will express set-theory and classic problems [Tharp] |
| Full Idea: The expressive power of second-order logic is too great to admit a proof procedure, but is adequate to express set-theoretical statements, and open questions such as the continuum hypothesis or the existence of big cardinals are easily stated. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10762 | In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp] |
| Full Idea: In sentential logic there is a simple proof that all truth functions, of any number of arguments, are definable from (say) 'not' and 'and'. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §0) | |
| A reaction: The point of 'say' is that it can be got down to two connectives, and these are just the usual preferred pair. |
| 10776 | The main quantifiers extend 'and' and 'or' to infinite domains [Tharp] |
| Full Idea: The symbols ∀ and ∃ may, to start with, be regarded as extrapolations of the truth functional connectives ∧ ('and') and ∨ ('or') to infinite domains. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §5) |
| 10774 | There are at least five unorthodox quantifiers that could be used [Tharp] |
| Full Idea: One might add to one's logic an 'uncountable quantifier', or a 'Chang quantifier', or a 'two-argument quantifier', or 'Shelah's quantifier', or 'branching quantifiers'. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §3) | |
| A reaction: [compressed - just listed for reference, if you collect quantifiers, like collecting butterflies] |
| 10773 | The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp] |
| Full Idea: The Löwenheim-Skolem property seems to be undesirable, in that it states a limitation concerning the distinctions the logic is capable of making, such as saying there are uncountably many reals ('Skolem's Paradox'). | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10777 | Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp] |
| Full Idea: Skolem deduced from the Löwenheim-Skolem theorem that 'the absolutist conceptions of Cantor's theory' are 'illusory'. I think it is clear that this conclusion would not follow even if elementary logic were in some sense the true logic, as Skolem assumed. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §7) | |
| A reaction: [Tharp cites Skolem 1962 p.47] Kit Fine refers to accepters of this scepticism about the arithmetic of infinities as 'Skolemites'. |
| 10765 | Soundness would seem to be an essential requirement of a proof procedure [Tharp] |
| Full Idea: Soundness would seem to be an essential requirement of a proof procedure, since there is little point in proving formulas which may turn out to be false under some interpretation. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10763 | Completeness and compactness together give axiomatizability [Tharp] |
| Full Idea: Putting completeness and compactness together, one has axiomatizability. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §1) |
| 10770 | If completeness fails there is no algorithm to list the valid formulas [Tharp] |
| Full Idea: In general, if completeness fails there is no algorithm to list the valid formulas. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
| A reaction: I.e. the theory is not effectively enumerable. |
| 10771 | Compactness is important for major theories which have infinitely many axioms [Tharp] |
| Full Idea: It is strange that compactness is often ignored in discussions of philosophy of logic, since the most important theories have infinitely many axioms. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
| A reaction: An example of infinite axioms is the induction schema in first-order Peano Arithmetic. |
| 10772 | Compactness blocks infinite expansion, and admits non-standard models [Tharp] |
| Full Idea: The compactness condition seems to state some weakness of the logic (as if it were futile to add infinitely many hypotheses). To look at it another way, formalizations of (say) arithmetic will admit of non-standard models. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10764 | A complete logic has an effective enumeration of the valid formulas [Tharp] |
| Full Idea: A complete logic has an effective enumeration of the valid formulas. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) |
| 10768 | Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp] |
| Full Idea: Despite completeness, the mere existence of an effective enumeration of the valid formulas will not, by itself, provide knowledge. For example, one might be able to prove that there is an effective enumeration, without being able to specify one. | |
| From: Leslie H. Tharp (Which Logic is the Right Logic? [1975], §2) | |
| A reaction: The point is that completeness is supposed to ensure knowledge (of what is valid but unprovable), and completeness entails effective enumerability, but more than the latter is needed to do the key job. |
| 14393 | The totality state is the most plausible truthmaker for negative existential truths [Merricks] |
| Full Idea: The claim that the totality state is the sole truthmaker for negative existential truths emerges as the best position for a truthmaker theorist. | |
| From: Trenton Merricks (Truth and Ontology [2007], 3.III) |
| 14413 | Some properties seem to be primitive, but others can be analysed [Merricks] |
| Full Idea: Some properties (perhaps negative charge, or the relation of identity) admit of no analysis, and so are primitive. But others are analysable, and so not primitive | |
| From: Trenton Merricks (Truth and Ontology [2007], 7.I) |
| 14416 | An object can have a disposition when the revelant conditional is false [Merricks] |
| Full Idea: It is possible for an object to have a disposition even though the relevant conditional is false. | |
| From: Trenton Merricks (Truth and Ontology [2007], 7.III) | |
| A reaction: This is the now standard observation that finks (killing the disposition) and antidotes (blocking the effect of the disposition) can intervene, as in safety mechanisms in electrical gadgets. There may be replies available here. |
| 14392 | Fregeans say 'hobbits do not exist' is just 'being a hobbit' is not exemplified [Merricks] |
| Full Idea: A Fregean about existence claims would say that 'that hobbits do not exist' is nothing other than the claim that 'being a hobbit' is not exemplified. | |
| From: Trenton Merricks (Truth and Ontology [2007], 3.II) | |
| A reaction: 'My passport has ceased to exist' seems to be a bit more dramatic than a relationship with a concept. |
| 14410 | You believe you existed last year, but your segment doesn't, so they have different beliefs [Merricks] |
| Full Idea: Your belief that you existed in the year 2000 is true; the belief of a segment of you that it then existed is false; so, by the indiscernibility of identicals, there must be two beliefs here. | |
| From: Trenton Merricks (Truth and Ontology [2007], 6.IV n20) | |
| A reaction: Merricks may be begging the question here. But in the segment view there is nothing which can truly believe it existed a year ago, so therefore nothing here has continued existence, so the segments cannot be part of a single thing. |
| 14417 | Counterfactuals aren't about actuality, so they lack truthmakers or a supervenience base [Merricks] |
| Full Idea: A counterfactual is not appropriately about the way anything is, …but about how something would be, had other things differed from how they actually are. As a result, true counterfactuals have neither truthmakers nor a superveniece base. | |
| From: Trenton Merricks (Truth and Ontology [2007], 7.IV) | |
| A reaction: Might not the truthmakers for counterfactuals reside in the dispositional facts about actuality? We assess the truth of counterfactuals in degrees, so something must determine our views. |
| 14402 | If 'Fido is possibly black' depends on Fido's counterparts, then it has no actual truthmaker [Merricks] |
| Full Idea: If Fido's being possibly black reduces (in Lewis's account) to the existence of black counterparts of Fido, then 'Fido is possibly black' is actually true, but it has no actually existing truthmaker. | |
| From: Trenton Merricks (Truth and Ontology [2007], 5.I) | |
| A reaction: This problem is increasingly the target of my views about dispositions and powers. Fido is not possibly a prize-winning novelist, but is possibly dead or in good health, because of the actual nature and dispositions of Fido. |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| Full Idea: Archelaus was the first person to say that the universe is boundless. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
| 14406 | Presentists say that things have existed and will exist, not that they are instantaneous [Merricks] |
| Full Idea: Presentists deny that everything is instantaneous; they think that many objects not only exist, but also have existed and will exist. | |
| From: Trenton Merricks (Truth and Ontology [2007], 6.I) | |
| A reaction: The second half is because presentists are committed to the truth of tensed existence claims (despite a lack of any theory as to how they work). Does anyone hold a theory of Instantaneousism? |
| 14407 | Presentist should deny there is a present time, and just say that things 'exist' [Merricks] |
| Full Idea: I think presentists should deny that there is anything at all that is the present time, just as they should deny that there are past times or future times. They should say that existing at the present time is just 'existing'. | |
| From: Trenton Merricks (Truth and Ontology [2007], 6.I) | |
| A reaction: The whole context is needed to understand Merrick's interesting claim. If there is no present, when can events happen? |
| 14411 | Maybe only presentism allows change, by now having a property, and then lacking it [Merricks] |
| Full Idea: Maybe presentism alone allows for genuine change, by permitting the direct having of a property by something and then, later, the absolute lacking of that property by that same thing. | |
| From: Trenton Merricks (Truth and Ontology [2007], 6.IV n23) | |
| A reaction: Four-dimensionalism (perdurantism) is the view which is most often charged with not explaining change, and that tends to be associated with eternalism. Are there just two coherent packages of views here? |
| 14405 | How can a presentist explain an object's having existed? [Merricks] |
| Full Idea: I am not sure what account presentists should give of an object's having existed. | |
| From: Trenton Merricks (Truth and Ontology [2007], 6.I) | |
| A reaction: Personally I am pretty puzzled by the eternalist and growing-block accounts of an object having existed, so we are all up a gum tree here. The best bet is to pull truth and existence apart, but heaven knows what that implies. See Idea 14399. |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
| Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
| A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |