49 ideas
| 18390 | All metaphysical discussion should be guided by a quest for truthmakers [Armstrong] |
| Full Idea: My plea, whatever conclusions are drawn, is to control the metaphysical discussion by continual reference to suggested truthmakers. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 08.7) | |
| A reaction: ...And my plea is to control metaethical discussion by continual reference to value-makers. In general, this is the approach which will deliver a unified account of the world. Truthmakers are the ideal restraint on extravagant metaphysics. |
| 5831 | The new view is that "water" is a name, and has no definition [Schwartz,SP] |
| Full Idea: Perhaps the modern view is best expressed as saying that "water" has no definition at all, at least in the traditional sense, and is a proper name of a specific substance. | |
| From: Stephen P. Schwartz (Intro to Naming,Necessity and Natural Kinds [1977], §III) | |
| A reaction: This assumes that proper names have no definitions, though I am not clear how we can grasp the name 'Aristotle' without some association of properties (human, for example) to go with it. We need a definition of 'definition'. |
| 18467 | Truth-making can't be entailment, because truthmakers are portions of reality [Armstrong] |
| Full Idea: Truth-making cannot be any form of entailment. Both terms of an entailment relation must be propositions, but the truth-making term of the truth-making relation is a portion of reality, and, in general at least, portions of reality are not propositions. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 02.3) | |
| A reaction: Along with Idea 18466, that seems to firmly demolish the idea that truth-making is a logical entailment. |
| 18468 | Armstrong says truthmakers necessitate their truth, where 'necessitate' is a primitive relation [Armstrong, by MacBride] |
| Full Idea: In a bold manouevre Armstrong posited a metaphysically primitive relation of necessitation, and then defined truth-makers in terms of this bridging relation, as a thing that necessitates something being true. | |
| From: report of David M. Armstrong (Truth and Truthmakers [2004], 02.3) by Fraser MacBride - Truthmakers 1.2 | |
| A reaction: [Not sure of page reference] Spelled out so clearly by MacBride, this sounds dubious. How many truths are necessitated by the City of London? Do truthmakers necessitate the existence of their truths? MacBride says it's a circular theory. |
| 18377 | Negative truths have as truthmakers all states of affairs relevant to the truth [Armstrong] |
| Full Idea: Postulate a higher-order state of affairs, of all the states of affairs in which Theaetetus is involved. Is this not a good candidate for a truthmaker for the negative truth that 'Theaetetus is not flying'? | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 05.2) | |
| A reaction: It certainly seems extravagant to need the whole universe to make true 'there are no lions in this room'. But for 'there are no unicorns' it is not clear which states of affairs unicorns are involved. (Armstrong is aware of this). |
| 18382 | The nature of arctic animals is truthmaker for the absence of penguins there [Armstrong] |
| Full Idea: Each of the arctic animals is by its nature different from a penguin, so this general state of affairs seems truthmaker enough for this negative existential. Similarly, the totality of all birds eliminates the phoenix. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 06.2) | |
| A reaction: Why is it 'animals' in one case, and 'birds' in the other? What if there was no life in arctic? Would the snow then do the job? This doesn't seem to work. |
| 18394 | In mathematics, truthmakers are possible instantiations of structures [Armstrong] |
| Full Idea: A mathematical entity exists if and only if it is possible that there be instantiations of that structure. This transforms the question of truthmakers for the existence of mathematical entities into a question of truthmakers for certain possibilities. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 09.3) | |
| A reaction: This modal approach to structuralism [for which he endorses Hellman 1989] opens up a modal approach to other truthmakers, which places dispositions at the centre of physical truthmaking. No sets of Meinongian objects? |
| 18386 | What is the truthmaker for 'it is possible that there could have been nothing'? [Armstrong] |
| Full Idea: It is possible that there could have been nothing. ...What would be its truthmaker? | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 07.4) | |
| A reaction: I suppose the truthmaker here is the whole of reality, with its dispositions and contingencies. But that won't do for 'possibly there might never have been anything'. In such a case there wouldn't be any truths. |
| 18384 | One truthmaker will do for a contingent truth and for its contradictory [Armstrong] |
| Full Idea: It seems reasonable to say that a truthmaker for a contingent truth is also a truthmaker for the truth that the contradictory of that truth is possible. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 07.2) | |
| A reaction: The truthmaker will have to be not only some fact, but also the additional fact that it is contingent, in order to generate the possibility of the contradictory. |
| 18387 | The truthmakers for possible unicorns are the elements in their combination [Armstrong] |
| Full Idea: The obvious minimal truthmaker for the truth that 'it is possible that a unicorn exists' is combinatorial. The elements of the combination are all that is needed. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 07.5) | |
| A reaction: This seems to imply that there are no possibilities which are not combinations of what currently exists. |
| 18381 | Necessitating general truthmakers must also specify their limits [Armstrong] |
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Full Idea:
The mereological sum of what happens to be all the men does not necessitate that it is all the men. So if truthmaking involves necessitation, then this object cannot be the complete truthmaker for |
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| From: David M. Armstrong (Truth and Truthmakers [2004], 06.1) | |
| A reaction: [He invokes Russell has his source] His point is that the truthmaker needs a further fact, beyond the men, which specifies that this is all of them. But only if truthmakers necessitate their truths (as Armstrong claims). I'm sympathetic to both claims. |
| 18396 | The set theory brackets { } assert that the member is a unit [Armstrong] |
| Full Idea: The idea is that braces { } attribute to an entity the place-holding, or perhaps determinable, property of unithood. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 09.5) | |
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A reaction:
I like this. There is Socrates himself, then there is my concept |
| 10702 | Set theory's three roles: taming the infinite, subject-matter of mathematics, and modes of reasoning [Potter] |
| Full Idea: Set theory has three roles: as a means of taming the infinite, as a supplier of the subject-matter of mathematics, and as a source of its modes of reasoning. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], Intro 1) | |
| A reaction: These all seem to be connected with mathematics, but there is also ontological interest in set theory. Potter emphasises that his second role does not entail a commitment to sets 'being' numbers. |
| 18393 | For 'there is a class with no members' we don't need the null set as truthmaker [Armstrong] |
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Full Idea:
The null class is useful in formal set theory, but I hope that does not require that there be a thing called the null class which is truthmaker for the strange proposition |
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| From: David M. Armstrong (Truth and Truthmakers [2004], 09.1) | |
| A reaction: It is not quite clear why it doesn't, but then it is not quite clear to philosophers what the status of the null set is, in comparison with sets that have members. |
| 10713 | Usually the only reason given for accepting the empty set is convenience [Potter] |
| Full Idea: It is rare to find any direct reason given for believing that the empty set exists, except for variants of Dedekind's argument from convenience. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 04.3) |
| 13044 | Infinity: There is at least one limit level [Potter] |
| Full Idea: Axiom of Infinity: There is at least one limit level. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 04.9) | |
| A reaction: A 'limit ordinal' is one which has successors, but no predecessors. The axiom just says there is at least one infinity. |
| 10708 | Nowadays we derive our conception of collections from the dependence between them [Potter] |
| Full Idea: It is only quite recently that the idea has emerged of deriving our conception of collections from a relation of dependence between them. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 03.2) | |
| A reaction: This is the 'iterative' view of sets, which he traces back to Gödel's 'What is Cantor's Continuum Problem?' |
| 13546 | The 'limitation of size' principles say whether properties collectivise depends on the number of objects [Potter] |
| Full Idea: We group under the heading 'limitation of size' those principles which classify properties as collectivizing or not according to how many objects there are with the property. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 13.5) | |
| A reaction: The idea was floated by Cantor, toyed with by Russell (1906), and advocated by von Neumann. The thought is simply that paradoxes start to appear when sets become enormous. |
| 10707 | Mereology elides the distinction between the cards in a pack and the suits [Potter] |
| Full Idea: Mereology tends to elide the distinction between the cards in a pack and the suits. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 02.1) | |
| A reaction: The example is a favourite of Frege's. Potter is giving a reason why mathematicians opted for set theory. I'm not clear, though, why a pack cannot have either 4 parts or 52 parts. Parts can 'fall under a concept' (such as 'legs'). I'm puzzled. |
| 10704 | We can formalize second-order formation rules, but not inference rules [Potter] |
| Full Idea: In second-order logic only the formation rules are completely formalizable, not the inference rules. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 01.2) | |
| A reaction: He cites Gödel's First Incompleteness theorem for this. |
| 5829 | We refer to Thales successfully by name, even if all descriptions of him are false [Schwartz,SP] |
| Full Idea: We can refer to Thales by using the name "Thales" even though perhaps the only description we can supply is false of him. | |
| From: Stephen P. Schwartz (Intro to Naming,Necessity and Natural Kinds [1977], §III) | |
| A reaction: It is not clear what we would be referring to if all of our descriptions (even 'Greek philosopher') were false. If an archaeologist finds just a scrap of stone with a name written on it, that is hardly a sufficient basis for successful reference. |
| 5830 | The traditional theory of names says some of the descriptions must be correct [Schwartz,SP] |
| Full Idea: The traditional theory of proper names entails that at least some combination of the things ordinarily believed of Aristotle are necessarily true of him. | |
| From: Stephen P. Schwartz (Intro to Naming,Necessity and Natural Kinds [1977], §III) | |
| A reaction: Searle endorses this traditional theory. Kripke and co. tried to dismiss it, but you can't. If all descriptions of Aristotle turned out to be false (it was actually the name of a Persian statue), our modern references would have been unsuccessful. |
| 10703 | Supposing axioms (rather than accepting them) give truths, but they are conditional [Potter] |
| Full Idea: A 'supposition' axiomatic theory is as concerned with truth as a 'realist' one (with undefined terms), but the truths are conditional. Satisfying the axioms is satisfying the theorem. This is if-thenism, or implicationism, or eliminative structuralism. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 01.1) | |
| A reaction: Aha! I had failed to make the connection between if-thenism and eliminative structuralism (of which I am rather fond). I think I am an if-thenist (not about all truth, but about provable truth). |
| 18392 | Classes have cardinalities, so their members must all be treated as units [Armstrong] |
| Full Idea: Classes, because they have a particular cardinality, are essentially a certain number of ones, things that, within the particular class, are each taken as a unit. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 09.1) | |
| A reaction: [Singletons are exceptions] So units are basic to set theory, which is the foundations of technical analytic philosophy (as well as, for many, of mathematics). If you can't treat something as a unit, it won't go into set theory. Vagueness... |
| 10712 | If set theory didn't found mathematics, it is still needed to count infinite sets [Potter] |
| Full Idea: Even if set theory's role as a foundation for mathematics turned out to be wholly illusory, it would earn its keep through the calculus it provides for counting infinite sets. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 03.8) |
| 17882 | It is remarkable that all natural number arithmetic derives from just the Peano Axioms [Potter] |
| Full Idea: It is a remarkable fact that all the arithmetical properties of the natural numbers can be derived from such a small number of assumptions (as the Peano Axioms). | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 05.2) | |
| A reaction: If one were to defend essentialism about arithmetic, this would be grist to their mill. I'm just saying. |
| 18385 | Logical atomism builds on the simple properties, but are they the only possible properties? [Armstrong] |
| Full Idea: One of the assumptions of logical atomism is that all structural properties, all complex properties, are composed of simple properties and relations. ...But does the totality of the simple properties consist of the only possible simple properties? | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 07.3) | |
| A reaction: This refers to what Lewis calls 'alien' properties - possible properties that cannot even be constructed from actual properties. Armstrong's question is about the truthmakers for such things. A bit speculative... |
| 18391 | 'Naturalism' says only the world of space-time exists [Armstrong] |
| Full Idea: I define 'naturalism' as the hypothesis that the world of space-time is all that there is. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 09.1) | |
| A reaction: This is helpful, because it doesn't mention the nature of the physical matter contained in space-time, leaving theories like panpsychism as possible naturalistic theories. Galen Strawson, for example. |
| 18374 | Truthmaking needs states of affairs, to unite particulars with tropes or universals. [Armstrong] |
| Full Idea: There must exist states of affairs as truthmakers, to get us beyond 'loose and separate' entities. ...They can be bundles of tropes, or trope-with-particular, or bundles of universals ('compresence'), or instantiations. They are an addition to ontology. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 04.5) | |
| A reaction: Armstrong is the great champion of states of affairs. They seem rather vague to me, and disconcertingly timeless. |
| 13043 | A relation is a set consisting entirely of ordered pairs [Potter] |
| Full Idea: A set is called a 'relation' if every element of it is an ordered pair. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 04.7) | |
| A reaction: This is the modern extensional view of relations. For 'to the left of', you just list all the things that are to the left, with the things they are to the left of. But just listing the ordered pairs won't necessarily reveal how they are related. |
| 18372 | We need properties, as minimal truthmakers for the truths about objects [Armstrong] |
| Full Idea: The 'thing itself' seems not be a minimal truthmaker for the thing having its particular mass. ...The thing has a great many other properties. ...It seems entirely reasonable to postulate that the object has properties that are objectively there. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 04.2) | |
| A reaction: This is Armstrong using the truthmaker principle to argue for the existence of properties (as instantiated universals). I like truthmakers, but truths do not have enough precision in their parts for us to read off reality from them. |
| 18379 | The determinates of a determinable must be incompatible with each other [Armstrong] |
| Full Idea: A set of determinates under the one determinable are incompatible by definition. If an object is not one mile in length, then its actual length will be incompatible with being one mile in length. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 05.2.1) | |
| A reaction: This is a much better general version of the standard example 'if it is red it can't be green'. Armstrong uses it to give a more precise account of incompatibility. Useful. |
| 18378 | Length is a 'determinable' property, and one mile is one its 'determinates' [Armstrong] |
| Full Idea: Length is a 'determinable' property; being some particular length, such as a mile, is one of its 'determinates'. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 05.2.1) | |
| A reaction: The seem to be 'type' and 'token' properties, except that this other vocabulary indicates the link between them. |
| 18373 | If tropes are non-transferable, then they necessarily belong to their particular substance [Armstrong] |
| Full Idea: 'Non-transferable' theories of tropes hold that the mass is of this stone by necessity. It is an identity condition for the property. Every property then becomes an essential property. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 04.3) | |
| A reaction: [He cites Martin and Heil for this view] It is hard to see in this proposal how the trope is in any way separate from its substance, and hence it seems a bit of a vacuous theory. (The other theories of properties aren't much cop either). |
| 18400 | Properties are not powers - they just have powers [Armstrong] |
| Full Idea: Properties are not powers. But properties have powers. They bestow powers. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 10.4) | |
| A reaction: I think this is the wrong way round. In this view, powers become extremely vague things, ranging from the fine-grained to the hugely broad. It seems to me that powers are precise and real, but properties are the vague unhelpful things. |
| 18397 | Powers must result in some non-powers, or there would only be potential without result [Armstrong] |
| Full Idea: Powers must surely issue in manifestations that are something more than just powers. A world where potency never issued in act, but only in more potency, would be one where one travelled without ever having the possibility of arriving. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 10.4) | |
| A reaction: Tricky. The picture I favour is that the distinction between powers and categorical properties is a misunderstanding. What is fundamental is active and powerful categoricals. |
| 18399 | How does the power of gravity know the distance it acts over? [Armstrong] |
| Full Idea: If masses are powers, the forces generated between two particulars have to vary inversely with the square of their distance apart. Have not the masses got to 'know' at what distance they are from each other, to exert the right amount of force? | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 10.4) | |
| A reaction: This seems like a good warning against a simplistic account of powers doing all the work, but I suspect that more sophisticated physics would offer the fan of powers a solution here. The power is to 'spread' the force around. |
| 18371 | The class of similar things is much too big a truthmaker for the feature of a particular [Armstrong] |
| Full Idea: For a Class Nominalist 'the class of all 4-kilo objects' is the truthmaker for the truth that the particular has just that mass. Yet this looks far too big! Would not the object still be four kilos even if the other members of the class had never existed? | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 04.2) | |
| A reaction: This seems so obvious to me as to be hardly worth saying. To identify redness with the class of red entities just seems crazy. Why do they belong in that class? Armstrong is illustrating the value of the truthmaker idea in philosophy. |
| 13042 | If dependence is well-founded, with no infinite backward chains, this implies substances [Potter] |
| Full Idea: The argument that the relation of dependence is well-founded ...is a version of the classical arguments for substance. ..Any conceptual scheme which genuinely represents a world cannot contain infinite backward chains of meaning. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 03.3) | |
| A reaction: Thus the iterative conception of set may imply a notion of substance, and Barwise's radical attempt to ditch the Axiom of Foundation (Idea 13039) was a radical attempt to get rid of 'substances'. Potter cites Wittgenstein as a fan of substances here. |
| 13041 | Collections have fixed members, but fusions can be carved in innumerable ways [Potter] |
| Full Idea: A collection has a determinate number of members, whereas a fusion may be carved up into parts in various equally valid (although perhaps not equally interesting) ways. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 02.1) | |
| A reaction: This seems to sum up both the attraction and the weakness of mereology. If you doubt the natural identity of so-called 'objects', then maybe classical mereology is the way to go. |
| 18389 | When entities contain entities, or overlap with them, there is 'partial' identity [Armstrong] |
| Full Idea: There is 'partial identity' where one entity contains another with something to spare, or else where entities overlap each other. ...Extensive quantities, such as length and mass, are the particularly plausible cases. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 08.5) | |
| A reaction: This looks like a very useful concept which deserves wider use. It will help discussions of rivers, statues, intersecting roads etc. |
| 10709 | Priority is a modality, arising from collections and members [Potter] |
| Full Idea: We must conclude that priority is a modality distinct from that of time or necessity, a modality arising in some way out of the manner in which a collection is constituted from its members. | |
| From: Michael Potter (Set Theory and Its Philosophy [2004], 03.3) | |
| A reaction: He is referring to the 'iterative' view of sets, and cites Aristotle 'Metaphysics' 1019a1-4 as background. |
| 18388 | Possible worlds don't fix necessities; intrinsic necessities imply the extension in worlds [Armstrong] |
| Full Idea: It seems natural and plausible to say that it is the fact that a necessary truth is itself necessary that determines its truth in all possible worlds. This intension determines its extension across possible worlds. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 08.1) | |
| A reaction: Well said. To me (but not to Armstrong) this implies essentialism, that the necessity arises from the intrinsic natures of the things involved. The whole Lewisian approach of explaining things by mapping them strikes me as wrong. |
| 18375 | General truths are a type of negative truth, saying there are no more ravens than black ones [Armstrong] |
| Full Idea: General truths are a species of negative truth, 'no more' truths, asserting that there are no more men than the mortal ones, no more ravens than the black ones. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 05.1) | |
| A reaction: He goes on to distinguish between 'absences' and 'limits' in this area. |
| 5826 | The intension of "lemon" is the conjunction of properties associated with it [Schwartz,SP] |
| Full Idea: The conjunction of properties associated with a term such as "lemon" is often called the intension of the term "lemon". | |
| From: Stephen P. Schwartz (Intro to Naming,Necessity and Natural Kinds [1977], §II) | |
| A reaction: The extension of "lemon" is the set of all lemons. At last, a clear explanation of the word 'intension'! The debate becomes clear - over whether the terms of a language are used in reference to ideas of properties (and substances?), or to external items. |
| 18368 | For all being, there is a potential proposition which expresses its existence and nature [Armstrong] |
| Full Idea: The thesis of 'expressibility' says that for all being, there is a proposition (perhaps one never formulated by any mind at any time) that truly renders the existence and nature of this being. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 02.3.2) | |
| A reaction: [He credits Stephen Read 2000:68-9 for this] Armstrong accepts this, but I deny it. I can't make any sense of this vast plethora of propositions, each exactly expressing some minute nuance of the infinity complexity of all being. |
| 18370 | A realm of abstract propositions is causally inert, so has no explanatory value [Armstrong] |
| Full Idea: We could not stand in any causal or nomic relation to a realm of propositions over and above the space-time world, ...so it is unclear that such a postulation is of any explanatory value. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 02.6) | |
| A reaction: I agree, and I like Armstrong's appeal to explanation as a criterion for whether we should make an ontological commitment here. I am baffled by anyone who thinks reality is crammed full of unarticulated propositions. Only a philosopher.... |
| 18380 | Negative causations supervene on positive causations plus their laws? [Armstrong] |
| Full Idea: Is it not very plausible that negative causations supervene on the positive causations together with the laws that govern the positive causations? | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 05.2.3) | |
| A reaction: This obviously has a naturalistic appeal, since all causation can then be based on the actual world. |
| 18401 | The pure present moment is too brief to be experienced [Armstrong] |
| Full Idea: The metaphysical present will be a strict instant, or, if time is not infinitely divisible, the present will be a minimum granule of duration. But strict instants or minimal granules of duration, if these exist, cannot be experienced. | |
| From: David M. Armstrong (Truth and Truthmakers [2004], 11) | |
| A reaction: He points out that this is ironic, since Presentism lies on the basic experience of the present. |