43 ideas
| 2945 | Most philosophers start with reality and then examine knowledge; Descartes put the study of knowledge first [Lehrer] |
| Full Idea: Some philosophers (e.g Plato) begin with an account of reality, and then appended an account of how we can know it, ..but Descartes turned the tables, insisting that we must first decide what we can know. | |
| From: Keith Lehrer (Theory of Knowledge (2nd edn) [2000], I p.2) |
| 22438 | Philosophy is largely concerned with finding the minimum that science could get by with [Quine] |
| Full Idea: Philosophy is in large part concerned with ...what science could get along with, could be reconstructed by means of, as distinct from what science has historically made us of. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: This nicely summarises the programme for the whole of the philosophy of David Lewis, who was Quine's pupil. If you start by asking what it could 'get by with', it is not surprising that simplicity is the top intellectual virtue for both of them. |
| 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. |
| 2946 | You cannot demand an analysis of a concept without knowing the purpose of the analysis [Lehrer] |
| Full Idea: An analysis is always relative to some objective. It makes no sense to simply demand an analysis of goodness, knowledge, beauty or truth, without some indication of the purpose of the analysis. | |
| From: Keith Lehrer (Theory of Knowledge (2nd edn) [2000], I p.7) | |
| A reaction: Your dismantling of a car will go better if you know what a car is for, but you can still take it apart in ignorance. |
| 22436 | Logicians don't paraphrase logic into language, because they think in the symbolic language [Quine] |
| Full Idea: The logician does not even need to paraphrase the vernacular into his logical notation, for he has learned to think directly in his logical notation, or even (which is the beauty of the thing) to let it think for him. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: See Williamson's love of logic (and his book on modal metaphysics). This idea embodies the dream of hardcore Frege-Russellian analytic philosophers. I wish someone had told me when I studied logic that the target was to actually think symbolically. |
| 22431 | Good algorithms and theories need many occurrences of just a few elements [Quine] |
| Full Idea: The power and simplicity of an algorithm, or indeed of any theory, depend on there being many occurrences of few elements rather than few occurrences of many. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], III) | |
| A reaction: Not sure how this applies to a software function. One which produces a good result from a large number of input variables sounds particularly impressive to me. Many occurrences of a single variable sounds rather inefficient. |
| 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? |
| 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. |
| 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. |
| 18381 | Necessitating general truthmakers must also specify their limits [Armstrong] |
|
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 |
|
| 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. |
| 22435 | The logician's '→' does not mean the English if-then [Quine] |
| Full Idea: The logician drops 'if-then' in favour of '→' without ever entertaining the mistaken idea that they are synonymous. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: [Quine uses the older horseshoe symbol] The conditional in English is not well understood, whereas the symbol is unambiguous. A warning to myself, since I have a tendency to translate symbols into English all the time. [p.156 'implies' is worse!] |
| 22433 | It is important that the quantification over temporal entities is timeless [Quine] |
| Full Idea: It would be hard to exaggerate the importance of recognising the timelessness of quantification over temporal entities. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], IV) | |
| A reaction: 'Some moments in this cricket match were crucial'. The domain is not timeless, but consists of moments in this match. Can you say the quantifier is timeless but its domain is not? Only in the sense that 'very' is a timeless word, I think. |
| 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) | |
|
A reaction:
I like this. There is Socrates himself, then there is my concept |
| 18393 | For 'there is a class with no members' we don't need the null set as truthmaker [Armstrong] |
|
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 |
|
| 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. |
| 22437 | Logical languages are rooted in ordinary language, and that connection must be kept [Quine] |
| Full Idea: A logical language is not independent of ordinary language. It has its roots in ordinary language, and these roots are not to be severed. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: Music to my ears. When you study logic, no one has to teach you what the words 'or' and 'if-then' mean, but they are disambiguated by the symbolism. The roots of logic are in ordinary talk of 'and', 'or' and 'not', which is the real world. |
| 22434 | Reduction to logical forms first simplifies idioms and grammar, then finds a single reading of it [Quine] |
| Full Idea: Ordinary language is reduced to logical form in two ways: reduction of the variety of idioms and grammatical constructions, and reduction of each surviving idiom to one fixed and convenient interpretation. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], V) | |
| A reaction: Is there a conflict between a 'fixed' and a 'convenient' result? By 'fixed' I suppose he means it is a commitment (to not waver). What is the logical form of a sentence which is deliberately ambiguous? |
| 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... |
| 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. |
| 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. |
| 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. |
| 22432 | Normally conditionals have no truth value; it is the consequent which has a conditional truth value [Quine] |
| Full Idea: Ordinarily the conditional is not thought of as true or false at all, but rather the consequent is thought of as conditionally true or false given the antecedent. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], III) | |
| A reaction: At first this seems obvious, but a conditional asserts a relationship between two propositions, and so presumably it is true if that relationship exists. 'Is it actually true that if it is Monday then everyone in the office is depressed?'. |
| 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. |
| 22430 | If we understand a statement, we know the circumstances of its truth [Quine] |
| Full Idea: We understand under what circumstances to say of any given statement that it is true, just as clearly as we understand the statement itself. | |
| From: Willard Quine (Mr Strawson on Logical Theory [1953], II) | |
| A reaction: This probably shouldn't be taken as a theory of meaning (in which Quine doesn't really believe) but as a plausible statement of correlated facts. Hypothetical assertions might be a problem case. 'If only I could be in two places at once'? |
| 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. |
| 13713 | Quine holds time to be 'space-like': past objects are as real as spatially remote ones [Quine, by Sider] |
| Full Idea: Quine's view is that time is 'space-like'. Past objects are as real as present ones; they're just temporally distant, just as spatially distant objects are just as real as the ones around here. | |
| From: report of Willard Quine (Mr Strawson on Logical Theory [1953]) by Theodore Sider - Logic for Philosophy 7.3.1 | |
| A reaction: Something is a wrong with a view that says that a long-dead person is just as real as one currently living. Death is rather more than travelling to a distant place. Arthur Prior responded to Quine by saying 'tense operators' are inescapable. |
| 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. |