195 ideas
| 2937 | What we cannot speak about we must pass over in silence [Wittgenstein] |
| Full Idea: What we cannot speak about we must pass over in silence. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 7) | |
| A reaction: This is either a boring truism, or points towards some sort of verificationism (where we can speak meaninglessly). Compare Ideas 7973 and 6870. |
| 6870 | I say (contrary to Wittgenstein) that philosophy expresses what we thought we must be silent about [Ansell Pearson on Wittgenstein] |
| Full Idea: I recognise the incredible force of Wittgenstein's closing statement in the 'Tractatus', but I hold the opposite view: philosophy exists to give expression to that which we think we can only remain silent about. | |
| From: comment on Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 7) by Keith Ansell Pearson - Interview with Baggini and Stangroom p.267 | |
| A reaction: A wonderful remark, with which I totally agree. Compare Idea 1596. I think it is just a fact that philosophers are able to articulate a huge number of ideas which other intelligent people find very interesting but on which they are unable to speak. |
| 16281 | Honesty requires philosophical theories we can commit to with our ordinary commonsense [Lewis] |
| Full Idea: The maxim of honesty: never put forward a philosophical theory that you yourself cannot believe in your least philosophical and most commonsensical moments. | |
| From: David Lewis (On the Plurality of Worlds [1986], 2.8) | |
| A reaction: I take it as important that this test is according to the philosopher's commonsense, and not according to some populist idea. This would allow, for example, for commonsense to be sensitive to scientific knowledge, or awareness of the logic. |
| 2944 | If a question can be framed at all, it is also possible to answer it [Wittgenstein] |
| Full Idea: If a question can be framed at all, it is also possible to answer it. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.5) | |
| A reaction: Just the sort of unsubstantiated metaphysical claim that philosophers are always making. |
| 9810 | The 'Tractatus' is a masterpiece of anti-philosophy [Badiou on Wittgenstein] |
| Full Idea: The 'Tractatus' is without doubt one of the masterpieces of anti-philosophy. | |
| From: comment on Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Alain Badiou - Mathematics and Philosophy: grand and little p.16 | |
| A reaction: French philosophers do love making wicked remarks like that. It seems that analysis is anti-philosophy, or 'little' philosophy in Badiou's parlance. |
| 23459 | This work solves all the main problems, but that has little value [Wittgenstein] |
| Full Idea: I believe myself to have found, on all essential points, the final solution of the problems. ….and this work shows how little is achieved when these problems are solved. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], Pref) | |
| A reaction: This is LW's deep pessimism about the value of philosophy, right from the start. You can only idolise LW if you agree with him on this. |
| 23512 | Once you understand my book you will see that it is nonsensical [Wittgenstein] |
| Full Idea: Anyone who understands me eventually recognises my propositions as nonsensical, when he has used them - as steps - to climb up beyond them. (He must, so to speak, throw away the ladder after he has climbed up it.) | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.54) | |
| A reaction: A much discussed passage. It can't possibly say that his book is pointless, because you can't attain this recognition without climbing his ladder. He speaks like an eastern guru. Perhaps Hume should have ended 'so commit my book to the flames'? |
| 16288 | Analysis reduces primitives and makes understanding explicit (without adding new knowledge) [Lewis] |
| Full Idea: The object of analysis is to reduce our burden of primitive notions, and to make tacit understanding explicit - not to bootstrap ourselves into understanding what we didn't understand at all beforehand. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.2) | |
| A reaction: I am particularly keen on the idea of 'making tacit understanding explicit'. I connect this with faith in intuition, and with the coherence view of justification. |
| 2938 | The limits of my language means the limits of my world [Wittgenstein] |
| Full Idea: The limits of my language means the limits of my world. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.6) | |
| A reaction: This is dangerous rubbish. For a start, if you accept (as you should) the existence of propositions, our heads are full of unarticulated ones. And truth emerges by degrees from what cannot be articulated. |
| 6429 | All complex statements can be resolved into constituents and descriptions [Wittgenstein] |
| Full Idea: Every statement about complexes can be resolved into a statement about their constituents and into the propositions that describe the complexes completely. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0201) | |
| A reaction: Russell says this embodies Wittgenstein's belief in analysis. Obviously Wittgenstein is making this claim 'in principle', as life is very short, and people are rather dim. I don't know how to begin evaluating such a claim. |
| 23492 | Our language is an aspect of biology, and so its inner logic is opaque [Wittgenstein] |
| Full Idea: Everyday language is a part of the human organism and is no less complicated than it. It is not humanly possible to gather immediately from it what the logic of language is. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.002) | |
| A reaction: It is normally assumed that ordinary language philosophy was derived from the later Wittgenstein, but this para in the Tractatus seems to contain the germ of the idea. He is pessimistic about finding logical forms. |
| 23510 | Most philosophical questions arise from failing to understand the logic of language [Wittgenstein] |
| Full Idea: Most of the propositions and questions of philosophers arise from our failure to understand the logic of our language. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.003) | |
| A reaction: I'm not sure what the scope of 'logic' is here. I suppose it means everything about language which is expounded in the Tractatus. I assume this includes Plato and Aristotle? I don't think I agree. It's about concepts, not about logic. |
| 23499 | This book says we should either say it clearly, or shut up [Wittgenstein] |
| Full Idea: The whole sense of the book might be summed up in the following words: what can be said at all can be said clearly, and what we cannot talk about we must pass over in silence. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], Pref) | |
| A reaction: This also provides the last sentence of his book. I think this is an axiom of modern analytic philosophy. The dream is to clarify everything, and belief that this is possible puts logic centre-stage, as the most precise language available. |
| 23508 | Science is all the true propositions [Wittgenstein] |
| Full Idea: The totality of true propositions is the whole of natural science (or the whole corpus of the natural sciences). | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.11) | |
| A reaction: So if it is true, it is science. What about truths about science? What about true speculations beyond science? What about bad science? What about trivial everyday truths? This is said to be a rare precursor of logical positivism in Tractatus. |
| 2939 | If a sign is useless it is meaningless; that is the point of Ockham's maxim [Wittgenstein] |
| Full Idea: If a sign is useless it is meaningless. That is the point of Occam's maxim. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 3.328) |
| 9651 | Verisimilitude might be explained as being close to the possible world where the truth is exact [Lewis] |
| Full Idea: We might explain the closeness to the truth (or 'verisimilitude') in terms of closeness of possible worlds. A theory is close to the truth to the extent that our world resembles some world where that theory is exactly true. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.3) | |
| A reaction: [Lewis cites Risto Hilpinen for this thought] I am always puzzled why Lewis and co. talk of whole worlds in their accounts. If I am close to the truth about cooking a good omelette, what has the rest of the world got to do with it? |
| 10910 | The best account of truth-making is isomorphism [Wittgenstein, by Mulligan/Simons/Smith] |
| Full Idea: The most sophisticated account of truth-making to have appeared to date is the 'isomorphism' theory of the Tractatus. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Mulligan/Simons/Smith - Truth-makers §5 | |
| A reaction: Wittgenstein's theory is clearly closely related to Russell's 'congruence' theory of correspondence of around 1912. |
| 23462 | He says the world is the facts because it is the facts which fix all the truths [Wittgenstein, by Morris,M] |
| Full Idea: Wittgenstein is thinking of the world as what makes truths true. …To get all the truths fixed we need more than the things: we need, as it were, the way things are - that is to say, the facts. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 1.12) by Michael Morris - Guidebook to Wittgenstein's Tractatus 1 | |
| A reaction: Morris says this is 'sometimes suggested'. It strikes me as plausible, and makes LW a key source for the modern truthmaker idea. Perhaps in David Lewis's version of it. The facts include the relations and processes of the things. |
| 18349 | All truths have truth-makers, but only atomic truths correspond to them [Wittgenstein, by Rami] |
| Full Idea: In 1922 Wittgenstein said that every truth has a truth-maker, but only atomic truths correspond to their truth-makers. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Adolph Rami - Introduction: Truth and Truth-Making note 04 | |
| A reaction: Presumably this is what logical atomism is meant to be (cf Russell). The atomic sentences plug into the world, and the rest are constructions from them, making the latter more remote from the truth-makers. |
| 10967 | Wittgenstein's picture theory is the best version of the correspondence theory of truth [Read on Wittgenstein] |
| Full Idea: Wittgenstein's picture theory is without doubt the best thought-out and developed of all the versions of the correspondence theory of truth. | |
| From: comment on Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Stephen Read - Thinking About Logic Ch.1 |
| 7087 | Language is [propositions-elementary propositions-names]; reality is [facts-states of affairs-objects] [Wittgenstein, by Grayling] |
| Full Idea: Language consists in propositions, which are made of 'elementary' propositions, which are based ultimately on names. This matches the world of facts, compounded out of 'states of affairs', which are compounded of objects. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by A.C. Grayling - Wittgenstein Ch.2 | |
| A reaction: This is Grayling's summary of the basic idea of the 'Tractatus'. The whole thing seems to be an elaborate version of Russell's 'congruence' account of the correspondence theory of truth. Later Wittgenstein is loss of faith in this theory. |
| 4702 | The account of truth in the 'Tractatus' seems a perfect example of the correspondence theory [Wittgenstein, by O'Grady] |
| Full Idea: Wittgenstein's account in the 'Tractatus' is often taken as a paradigm instance of a sophisticated correspondence theory of truth. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Paul O'Grady - Relativism Ch.2 | |
| A reaction: This might explain why I am so much more drawn to the 'Tractatus' than to the later relativistic anti-philosophical mind-eliminitavist, meaning-eliminativist Wittgenstein. |
| 7056 | Pictures reach out to or feel reality, touching at the edges, correlating in its parts [Wittgenstein] |
| Full Idea: A picture attaches to reality by reaching out to it; it is laid against reality like a measure; only the end-points actually touch the object; the pictorial relationship consists of correlations of picture's elements with things, the picture's feelers. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.1511-5) | |
| A reaction: (somewhat compressed). This is Wittgenstein's so-called 'picture theory' of meaning (replaced later by 'meaning is use'). It is perhaps better seen as an account of the correspondence theory of truth. Compare Russell's 'congruence' view (Idea 5427). |
| 23483 | Proposition elements correlate with objects, but the whole picture does not correspond to a fact [Wittgenstein, by Morris,M] |
| Full Idea: Correlation need only be between elements of the picture and things in reality; it is not also required that there be a correspondence between the picture as a whole and a fact in reality - so things can be depicted falsely. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.15121) by Michael Morris - Guidebook to Wittgenstein's Tractatus 3C | |
| A reaction: To turn his picture theory into a correspondence theory of truth would need a further step, of saying the proposition is true when the two structures coincide. I don't think LW says that. |
| 23502 | Logic fills the world, to its limits [Wittgenstein] |
| Full Idea: Logic pervades the world: the limits of the world are also its limits. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.61) | |
| A reaction: This is a gospel belief for hardcore analytic philosophy. Hence Williamson writes a book on modal logic as metaphysics. |
| 23504 | Logic concerns everything that is subject to law; the rest is accident [Wittgenstein] |
| Full Idea: The exploration of logic means the exploration of everything that is subject to law. And outside logic everything is accidental. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.3) | |
| A reaction: Why should laws be logical? Legislatures can pass whimsical laws. Does he mean that the laws of nature are logically necessary? He can't just mean logical laws. |
| 6428 | Wittgenstein is right that logic is just tautologies [Wittgenstein, by Russell] |
| Full Idea: I think Wittgenstein is right when he says (in the 'Tractatus') that logic consists wholly of tautologies. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Bertrand Russell - My Philosophical Development Ch.10 | |
| A reaction: Despite Russell's support, I find this hard to accept. While a 'pure' or 'Platonist' logic may be hard to demonstrate or believe, I have a strong gut feeling that logic is more of a natural phenomenon than a human convention. |
| 11062 | Logic is a priori because it is impossible to think illogically [Wittgenstein] |
| Full Idea: What makes logic a priori is the impossibility of illogical thought. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.4731) | |
| A reaction: That places the a priori aspect of it in us (in the epistemology), rather than in the necessity of the logic (the ontology), which is as Kripke says it should be. |
| 18277 | If q implies p, that is justified by q and p, not by some 'laws' of inference [Wittgenstein] |
| Full Idea: If p follows from q, I can make an inference from q to p, deduce p from q. The nature of the inference can be gathered only from the two propositions. They are the only possible justification of the inference. 'Laws of Inference' would be superfluous. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.132) | |
| A reaction: That seems to imply that each inference is judged on its particulars. But logic aims to be general. There seem to be 'laws' at a more complex level in the logic. |
| 18162 | The propositions of logic are analytic tautologies [Wittgenstein] |
| Full Idea: The propositions of logic are tautologies. Therefore the propositions of logic say nothing. (They are the analytic propositions). | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.1) |
| 7537 | Wittgenstein convinced Russell that logic is tautologies, not Platonic forms [Wittgenstein, by Monk] |
| Full Idea: Russell took a Platonist view of logic, but reading the 'Tractatus' convinced him that logic was purely linguistic, so-called 'logical truths' being nothing more than tautologies. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Ray Monk - Bertrand Russell: Spirit of Solitude Ch.1 | |
| A reaction: If p-and-q and p-or-q are both tautologies, how do you explain the difference between them? The first is an indicative proposition about the actual world, but the second is modal. They are asserting very different things. |
| 23496 | Two colours in the same place is ruled out by the logical structure of colour [Wittgenstein] |
| Full Idea: The simultaneous presence of two colours in the same place in the visual field is impossible, in fact logically impossible, since it is ruled out by the logical structure of colour. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.3751) | |
| A reaction: This sounds the wrong way around. We derive our concept of the logic of colour from experiencing the total incompatibility of two colours in the same location. What if each of our eyes saw a different colour? |
| 18154 | The sign of identity is not allowed in 'Tractatus' [Wittgenstein, by Bostock] |
| Full Idea: The 'Tractatus' does not allow the introduction of a sign for identity. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by David Bostock - Philosophy of Mathematics 9.B.4 |
| 13429 | The identity sign is not essential in logical notation, if every sign has a different meaning [Wittgenstein, by Ramsey] |
| Full Idea: Wittgenstein discovered that the sign of identity is not a necessary constituent of logical notation, but can be replaced by the convention that different signs must have different meanings. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Frank P. Ramsey - The Foundations of Mathematics p.139 | |
| A reaction: [Ramsey cites p.139 - need to track down the modern reference] Hence in modern logic it is usually necessary to say that we are using 'classical logic with identity', since the use of identity is very convenient, and reasonably harmless (I think). |
| 18268 | Apparent logical form may not be real logical form [Wittgenstein] |
| Full Idea: The apparent logical form of the proposition need not be its real logical form. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.0031), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 6 'The incom' | |
| A reaction: This is one of the key doctrines of modern analytic philosophy. |
| 10905 | My fundamental idea is that the 'logical constants' do not represent [Wittgenstein] |
| Full Idea: My fundamental idea is that the 'logical constants' do not represent; that the logic of facts does not allow of representation. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.0312) | |
| A reaction: This seems to a firm rebuttal of any sort of platonism about logic, and implies a purely formal account. |
| 23493 | 'Not' isn't an object, because not-not-p would then differ from p [Wittgenstein] |
| Full Idea: If there were an object called 'not', it would follow that 'not-not-p' would say something different from what 'p' said, just because the one proposition would then be about 'not', and the other would not. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.44) | |
| A reaction: That is, the first proposition would be about not-p, and the second would be about p. Assuming we can say what such things are 'about'. A rather good argument that the connectives are not entities. P and double-negated P should be indistinguishable. |
| 7784 | 'Object' is a pseudo-concept, properly indicated in logic by the variable x [Wittgenstein] |
| Full Idea: The variable name ‘x’ is the proper sign of the pseudo-concept object. Wherever the word ‘object’ (‘thing’, ‘entity’, etc.) is rightly used, it is expressed in logical symbolism by the variable name. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.1272) | |
| A reaction: This seems to be the germ of Quine's famous dictum (Idea 1610). I am not persuaded that because logic must handle an object as a variable, that it follows that we are dealing with a pseudo-concept. Let logic limp behind life. |
| 23506 | Names are primitive, and cannot be analysed [Wittgenstein] |
| Full Idea: A name cannot be dissected any further by means of a definition: it is a primitive sign. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 3.26) | |
| A reaction: All logicians and analytic philosophers seem to agree on this. He means terms which pick out specific objects. |
| 7089 | A name is primitive, and its meaning is the object [Wittgenstein] |
| Full Idea: A name means an object; an object is its meaning. ...A name cannot be dissected further by means of a definition: it is a primitive sign. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 3.203/3.26) | |
| A reaction: This is the optimistic view of names, that they are the point at which language plugs into the world (Russell preferred demonstratives for that job). Kripke's baptismal view of names has the same aspiration. |
| 9467 | Wittgenstein tried unsuccessfully to reduce quantifiers to conjunctions and disjunctions [Wittgenstein, by Jacquette] |
| Full Idea: Wittgenstein reduces the universal quantifier to conjunctions of singular predications, and the existential quantifier to disjunctions of singular predications. ..This is nowadays understood as a failed effort. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Dale Jacquette - Intro to III: Quantifiers p.143 | |
| A reaction: The problem this meets has something to do with infinite objects. In a domain of three objects it looks like a perfectly plausible strategy. 'All' is all three, and 'Some' is at least one of the three. |
| 15731 | Quantification sometimes commits to 'sets', but sometimes just to pluralities (or 'classes') [Lewis] |
| Full Idea: I consider some apparent quantification over sets or classes of whatnots to carry genuine ontological commitment to 'sets' of them, but sometimes it is innocent plural quantification committed only to whatnots, for which I use 'class'. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5 n37) | |
| A reaction: How do you tell whether you are committed to a set or not? Can I claim an innocent plurality each time, while you accuse me of a guilty set? Can I firmly commit to a set, to be told that I can never manage more than a plurality? |
| 15089 | Logical proof just explicates complicated tautologies [Wittgenstein] |
| Full Idea: Proof in logic is merely a mechanical expedient to facilitate recognition of tautologies in complicated cases. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.1262) |
| 13830 | Logical truths are just 'by-products' of the introduction rules for logical constants [Wittgenstein, by Hacking] |
| Full Idea: Wittgenstein's by-product theory is that the meanings of the logical constants are conveyed by their introduction rules, and these rules have as a by-product the class of logical truths. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Ian Hacking - What is Logic? §03 | |
| A reaction: I find this approach highly plausible. All the truths about chess openings are just a by-product of the original rules. |
| 19292 | Logic doesn't split into primitive and derived propositions; they all have the same status [Wittgenstein] |
| Full Idea: All the propositions of logic are of equal status: it is not the case that some of them are essentially primitive propositions and others essentially derived propositions. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.127) | |
| A reaction: So axioms are conventional. This specifically contradicts the claims of Frege and the earlier Russell. Their view is that logic has an explanatory essence, found in some core axioms or rules or concepts. I agree with them. |
| 18160 | The concept of number is just what all numbers have in common [Wittgenstein] |
| Full Idea: The concept of number is simply what is common to all numbers, the general form of number. The concept of number is the variable number. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.022) |
| 18153 | A number is a repeated operation [Wittgenstein] |
| Full Idea: A number is the index of an operation. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.021) | |
| A reaction: Roughly, this means that a number indicates how many times some basic operation has been performed. Bostock 2009:286 expounds the idea. |
| 18161 | The theory of classes is superfluous in mathematics [Wittgenstein] |
| Full Idea: The theory of classes is completely superfluous in mathematics. This is connected with the fact that the generality required in mathematics is not accidental generality. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.031) | |
| A reaction: This fits Russell's no-class theory, which rests everything instead on propositional functions. |
| 6849 | Wittgenstein hated logicism, and described it as a cancerous growth [Wittgenstein, by Monk] |
| Full Idea: Wittgenstein didn't just have an arguments against logicism; he hated logicism, and described is as a cancerous growth. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Ray Monk - Interview with Baggini and Stangroom p.12 | |
| A reaction: This appears to have been part of an inexplicable personal antipathy towards Russell. Wittgenstein appears to have developed a dislike of all reductionist ideas in philosophy. |
| 23509 | The logic of the world is shown by tautologies in logic, and by equations in mathematics [Wittgenstein] |
| Full Idea: The logic of the world, which is shown in tautologies by the propositions of logic, is shown in equations by mathematics. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.22) | |
| A reaction: White observes that this is Wittgenstein distinguishing logic from mathematics, and thus distancing himself from logicism. But see T 6.2. |
| 13133 | The world is facts, not things. Facts determine the world, and the world divides into facts [Wittgenstein] |
| Full Idea: The world is the totality of facts, not of things. The world is determined by the facts, and by their being all the facts. The totality of facts determines what is the case, and what is not the case. ..The world divides into facts. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 1 - 1.2) | |
| A reaction: This is said to be a radical new ontology, because the facts are held to be prior to the things and their properties, which are presumably abstractions from the primitive facts. The modern heir of this is Armstrong's 'states of affairs'. |
| 10470 | There are only two kinds: sets, and possibilia (actual and possible particulars) [Lewis, by Oliver] |
| Full Idea: Lewis's multi-purpose ontology seems to have only two kinds: sets and possibilia (actual and possible particulars). | |
| From: report of David Lewis (On the Plurality of Worlds [1986]) by Alex Oliver - The Metaphysics of Properties 3 | |
| A reaction: This is awfully like the ontology of his teacher Quine, but with the wicked addition of modal properties. It is no wonder that Lewis was a bit vague about the concrete boundary, as both of his kinds seem to be abstract. His Achilles' Heel? |
| 9650 | Supervenience concerns whether things could differ, so it is a modal notion [Lewis] |
| Full Idea: The idea of supervenience is when there could be no difference of one sort without difference of another sort. ..Clearly this 'could' indicates modality, and without modality we have nothing of interest. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.2) | |
| A reaction: This might explain why philosophers are going to be more at home with the concept than neuroscientists would be. |
| 7090 | The 'Tractatus' is an extreme example of 'Logical Atomism' [Wittgenstein, by Grayling] |
| Full Idea: The 'Tractatus' is an uncompromising, indeed an extreme, example of 'Logical Atomism' | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by A.C. Grayling - Wittgenstein Ch.2 | |
| A reaction: Russell talked about his 'logical atomism' after 1918, but this reminds us that Wittgenstein was fulfilling a task set for him by Russell. Wittgenstein's atoms are names-plus-objects, Russell's are demonstratives-plus-sensedata. |
| 23464 | In atomic facts the objects hang together like chain links [Wittgenstein] |
| Full Idea: In an atomic fact [Sachverhalt] the objects hang one in another, like the links of a chain | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.03), quoted by Homer - The Iliad | |
| A reaction: So the world consists of facts, but the facts are composed of objects. The point seems to be that the truths of language refer to the facts, rather than to the objects. Objects 'don't hang' together in the fact of a chance encounter. |
| 23471 | The structure of an atomic fact is how its objects combine; this possibility is its form [Wittgenstein] |
| Full Idea: The way in which objects hang together in the atomic fact is the structure of the atomic fact. …The form is the possibility of the structure. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.032-3) | |
| A reaction: I very much like the way LW adds a modal dimension to his ontology. Why doesn't he talk of 'relations', rather than 'hanging together'? |
| 21682 | If a proposition is elementary, no other elementary proposition contradicts it [Wittgenstein] |
| Full Idea: It is a sign of a proposition's being elementary that there can be no elementary proposition contradicting it. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.211) | |
| A reaction: It is a hallmark of atomic atoms that they have no relations with other atoms, but are wholly independent. This obviously invites the question of how they are united. Are logical connectives intrinsically relational logical atoms? |
| 22319 | Analysis must end in elementary propositions, which are combinations of names [Wittgenstein] |
| Full Idea: It is obvious that in the analysis of propositions we must come to elementary propositions, which consist of names in immediate combination. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.221), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 50 'Indep' | |
| A reaction: Not clear about 'combinations of names'. Does that include predicates? How do you combine two names? |
| 21683 | Nothing can be inferred from an elementary proposition [Wittgenstein] |
| Full Idea: From an elementary proposition no other can be inferred. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.134) | |
| A reaction: Russell was not so sure. This is the sort of remark that elicits from me the question that extravagent metaphysics also provokes - 'how on earth does he know what he claims to be true?'. |
| 8909 | Abstractions may well be verbal fictions, in which we ignore some features of an object [Lewis] |
| Full Idea: The inevitable hypothesis is that abstractions are verbal fictions. We say we are speaking about abstractions when we are speaking abstractly about the original thing. We are ignoring some features, not introducing a new thing lacking those features. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: Thus Lewis ends up pretty close to Locke and the traditional view. This makes abstraction not a feat of platonic perception, in which magical non-material objects are spotted, but a feat of counterfactual imagination. |
| 23473 | Do his existent facts constitute the world, or determine the world? [Morris,M on Wittgenstein] |
| Full Idea: Wittgenstein's writing here is loose, and he seems to be conflating two claims: 1) The totality of existent facts is the world (everything that is the case), and 2) The totality of existent facts determines everything that is the case (the world). | |
| From: comment on Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.04) by Michael Morris - Guidebook to Wittgenstein's Tractatus 1E | |
| A reaction: [Also 2.06 and 2.063] Morris says he must actually mean the second version. |
| 22311 | The world is determined by the facts, and there are no further facts [Wittgenstein] |
| Full Idea: The world is determined by the facts, and by these being all the facts. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 1.11), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 47 'Mole' | |
| A reaction: He is denying negative facts (also written to Russell in 1919). Best approached through truthmakers, I suspect. There is no truthmaker for the supposed factual claim 'there are birds on Mars' - so it is a fact that there are no birds on Mars. |
| 22313 | The existence of atomic facts is a positive fact, their non-existence a negative fact [Wittgenstein] |
| Full Idea: The existence of atomic facts we also call a positive fact, their non-existence a negative fact. b...The existence and non-existence of atomic facts is the reality. ...[2.063] the total reality is the world. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.06), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 47 'Mole' | |
| A reaction: Potter observes that he denies negative facts in a1919 letter to Russell, and at 1.11, but then affirms them at 2.06. |
| 22314 | On white paper a black spot is a positive fact and a white spot a negative fact [Wittgenstein] |
| Full Idea: On white paper, the fact that a point is black corresponds to a positive fact; to the fact that a point is white (not black), a negative fact. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.063), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 08 'Judg' | |
| A reaction: Elsewhere Wittgenstein is ambiguous as to whether he believes in negative facts [qv]. |
| 9057 | Vagueness is semantic indecision: we haven't settled quite what our words are meant to express [Lewis] |
| Full Idea: I regard vagueness as semantic indecision: where we speak vaguely, we have not troubled to settle which of some range of precise meanings our words are meant to express. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.4 n32) | |
| A reaction: But that seems to leave the problem of how you are going to decide the boundaries of 'heap' or 'bald', if we all agree to become more precise. In law precise boundaries are often drawn a bit arbitrarily, simply because a boundary is needed. |
| 9671 | Whether or not France is hexagonal depends on your standards of precision [Lewis] |
| Full Idea: Say that France is hexagonal, and you thereby set the standards of precision low, and you speak the truth; say that France is not hexagonal (preferably on some other occasion) and you set the standards high, and again you speak the truth. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.5) | |
| A reaction: This is very persuasive. It fits with my views on justification, which are to do with how high I (or more often 'we') decide to set the standards, thereby defining knowledge for that occasion. Hm. Has Lewis cracked vagueness? [P.S. NO!] |
| 7969 | The order of numbers is an internal relation, not an external one [Wittgenstein] |
| Full Idea: The order of the number-series is not governed by an external relation but by an internal relation. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.1252) | |
| A reaction: He seems to mean something like a tautology (see Idea 7968). It is, I take it, part of the concept of any given integer that it has a place in the series. But do the concepts arise self-evidently, or from nature? |
| 7968 | A relation is internal if it is unthinkable that its object should not possess it [Wittgenstein] |
| Full Idea: A relation is internal if it is unthinkable that its object should not possess it. (This shade of blue and that one stand, eo ipso, in the internal relation of lighter to darker. It is unthinkable that these two objects should not stand in this relation). | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.123) | |
| A reaction: An epistemological definition. If only one shade of blue existed, would it still have this internal relation? Are things therefore full of potential internal relations with non-existent things? |
| 15751 | Surely 'slept in by Washington' is a property of some bed? [Lewis] |
| Full Idea: That the most noteworthy property of this bed is that George Washington slept in it - surely this is true on some legitimate conception of properties? | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: Wrong! This example is a nice clear test case. This is an absurd slippery slope. A bed he once looked at? I would have thought this was a relation the bed once entered into, and a relation isn't a property. |
| 15735 | Properties don't have degree; they are determinate, and things have varying relations to them [Lewis] |
| Full Idea: I have made no place for properties that admit of degree, so that things may have more or less of the same property. There are plain properties, and then there are relations to them. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: An interesting question, little discussed. Elsewhere, Lewis ascribes all vagueness to our inadequate predicates, rather than to the world, which I find quite persuasive. |
| 9656 | The 'abundant' properties are just any bizarre property you fancy [Lewis] |
| Full Idea: Properties are 'sparse' or 'abundant'. The abundant properties may be as extrinsic, as gruesomely gerrymandered, as miscellaneously disjunctive, as you please. They pay no heed to the qualitative joints, but carve things up every which way. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: This seems to be a logician's idea, which is needed for the notion of a set as pure extension, but it has very little to do with what I understand by the word 'property'. Better to call it a 'categorization'. E.g. filing George W. Bush under 'jackal'. |
| 15737 | To be a 'property' is to suit a theoretical role [Lewis] |
| Full Idea: To deserve the name of 'property' is to be suited to play the right theoretical role. It is wrong to speak of 'the' role associated with the word 'property', as if it were fully and uncontroversially settled. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: Once again I see a chicken-and-egg problem. Surely something has a theoretical role because of its intrinsic character, or its prior definition? How could you formulate a theory if you lacked properties? We don’t meet properties as gaps in theories. |
| 15742 | A disjunctive property can be unnatural, but intrinsic if its disjuncts are intrinsic [Lewis] |
| Full Idea: A property can be unnatural by reason of disjunctiveness, as the property of being tripartite-or-liquid-or-cubical is, and it is intrinsic if its disjuncts are. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: This strikes me as being utterly, shockingly and disgracefully wrong. A disjunction can't possibly be a property. Can a person have the property of being 'fat or thin'? A disjunction offers candidates for properties, not the properties themselves. |
| 15397 | If a global intrinsic never varies between possible duplicates, all necessary properties are intrinsic [Cameron on Lewis] |
| Full Idea: Lewis defines a globally intrinsic property as one that never varies between duplicates across possible worlds. This has the immediate problem that any property that is necessarily had, or necessarily lacked, by every thing will be intrinsic. | |
| From: comment on David Lewis (On the Plurality of Worlds [1986], p.61-2) by Ross P. Cameron - Intrinsic and Extrinsic Properties 'Analysis' | |
| A reaction: [He also cites Langton and Lewis 1998] To me this is the sort of tangle you get into when you equate properties with predicates. The problem seems to concern necessary predicates (but those may not be necessary properties). |
| 15398 | Global intrinsic may make necessarily coextensive properties both intrinsic or both extrinsic [Cameron on Lewis] |
| Full Idea: If a globally intrinsic properties are those that never vary between duplicates across possible worlds, then necessarily coextensive properties will either be both intrinsic or both extrinsic. | |
| From: comment on David Lewis (On the Plurality of Worlds [1986], p.61-2) by Ross P. Cameron - Intrinsic and Extrinsic Properties 'Analysis' | |
| A reaction: Presumably this problem would arise if some intrinsic property entailed an extrinsic property (or, less likely, vice versa). These sorts of problems arise when you try to define everything extensionally (even across possible worlds). |
| 15741 | All of the natural properties are included among the intrinsic properties [Lewis] |
| Full Idea: It cannot be said that all intrinsic properties are perfectly natural, ...but it can plausibly be said that all perfectly natural properties are intrinsic. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: Idea 15742 give the example he uses to support this claim. I like the concept of 'intrinsic' properties, but cannot currently see any use for the concept of 'natural' ones. |
| 15752 | We might try defining the natural properties by a short list of them [Lewis] |
| Full Idea: We might try defining the natural properties by a short list, of the mass properties, charge properties, quark properties and flavours... | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5 n47) | |
| A reaction: He rejects this because of possible natural properties in other possible worlds. Defining anything by a list seems like cheating. Does John, Paul, George and Ringo 'define' something? |
| 14996 | Natural properties give similarity, joint carving, intrinsicness, specificity, homogeneity... [Lewis] |
| Full Idea: Sharing of [perfectly natural properties] makes for qualitative similarity, they carve at the joints, they are intrinsic, they are highly specific, the sets of their instances are ipso facto not highly miscellaneous. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: All this sounds like just what I want, but when I read Lewis he seems to be arriving at these natural properties by the wrong route. Too much Hume, too much extensionalism. |
| 15744 | We can't define natural properties by resemblance, if they are used to explain resemblance [Lewis] |
| Full Idea: Shall we say that natural properties are the ones whose instances are united by resemblance? - Not if we are going to say that resemblance is the sharing of natural properties. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: The target of this appears to be the proposal of Quinton. By now I have totally given up on so-called 'natural' properties. Lewis says the circularity (also in Idea 15743) is a reason to treat 'natural' here as primitive (though he rejects that). |
| 15743 | Defining natural properties by means of laws of nature is potentially circular [Lewis] |
| Full Idea: Shall we say that natural properties are the ones that figure in laws of nature? - Not if we are going to use naturalness of properties when we draw the line between laws of nature and accidental regularities. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: Personally I wouldn't dream of defining anything by saying that it figured in laws of nature. The laws, if there be such (see Mumford) are built up from more fundamental components, such as (perhaps) properties. |
| 15740 | I don't take 'natural' properties to be fixed by the nature of one possible world [Lewis] |
| Full Idea: Some people suppose my natural properties are distinguished by nature, and hence natural in one world and not another. I intend properties to be natural or unnatural simpliciter, not relative to one or another world. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5 n44) | |
| A reaction: This is an important warning for the likes of me. I've have begun to doubt the utility of the term 'natural' property, and this reinforces my view. |
| 16262 | Sparse properties rest either on universals, or on tropes, or on primitive naturalness [Lewis, by Maudlin] |
| Full Idea: Lewis surveys three accounts of sparse properties: a set of objects instantiating a single universal; a set of objects having as parts duplicates of some trope; and a set distinguished by a further unanalyzable, primitive characteristic of naturalness. | |
| From: report of David Lewis (On the Plurality of Worlds [1986], p.60-) by Tim Maudlin - The Metaphysics within Physics | |
| A reaction: The very idea of suggesting that a property is some set of objects strikes me as bizarre. I present you with a table full of objects and say that is the complete set of some property. You then have to study the objects to find out what the property is. |
| 15739 | There is the property of belonging to a set, so abundant properties are as numerous as the sets [Lewis] |
| Full Idea: The abundant properties far outrun the predicates of any language we could possibly possess. ...Properties are as abundant as the sets, because for any set whatever, there is the property of belonging to that set. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: The idea of calling such things 'properties' strikes me as preposterous, but it is interesting that we confront truths which outrun our predicates. We can't have all of these predicates together, but there is no impediment to any one of them. |
| 10723 | A property is the set of its actual and possible instances [Lewis, by Oliver] |
| Full Idea: Lewis proposes that a property is the set of its actual and possible instances. | |
| From: report of David Lewis (On the Plurality of Worlds [1986], 1.5) by Alex Oliver - The Metaphysics of Properties 10 | |
| A reaction: I just can't make sense of any proposal that a property is a set. Things fall into natural sets because they have properties. Only a philosopher would believe such a weird proposal as this one. Triangular and trilateral? |
| 15399 | The property of being F is identical with the set of objects, in all possible worlds, which are F [Lewis, by Cameron] |
| Full Idea: Lewis thought that the property of being F was identical with the set of objects, in all possible worlds, which are F. | |
| From: report of David Lewis (On the Plurality of Worlds [1986], §1.5) by Ross P. Cameron - Intrinsic and Extrinsic Properties | |
| A reaction: I can't make head or tail of a theory which says that a property is a set of objects. I'll show you a room full of objects and tell you they are a property. How are you going to work out what the property is? 'Being F' is a predicate, not a property! |
| 15732 | Properties don't seem to be sets, because different properties can have the same set [Lewis] |
| Full Idea: The usual objection to taking properties as sets is that different properties may happen to be coextensive. Creatures with hearts are creatures with kidneys. Talking donkeys are flying pigs (since there are none). Yet the properties differ. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: This is the difficulty which Lewis proposes to solve by defining properties across possible situations as well as actual ones, so that the properties can come apart. Nice move. |
| 15733 | Accidentally coextensive properties come apart when we include their possible instances [Lewis] |
| Full Idea: In modal realism, 'accidentally coextensive' properties are not coextensive. They only appear so when we ignore their other-worldly instances. If we consider all instances, then it never can happen that two properties are coextensive but might have been. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: It is not clear why this 'can never happen'. Maybe even God can't make a hearted creature without kidneys. Lewis is aware of this question. |
| 15734 | If a property is relative, such as being a father or son, then set membership seems relative too [Lewis] |
| Full Idea: A property that is instantiated in a relative way (such as being a father or a son) could not be the set of its instances? Is the thing to be included in the set or not? | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: He says philosophers contrive ways to define properties as functions, but he prefers to call such properties 'relations', and define them that way. It never even occurred to me that 'being a son' was one of my properties, but what do I know? |
| 9655 | Trilateral and triangular seem to be coextensive sets in all possible worlds [Lewis] |
| Full Idea: We can't take a property as sets of this-worldly instances, because two properties may be coextensive. Some say it is just as bad in all possible worlds, if the property is necessary, as when all triangles are trilateral, which seem different. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: [compressed] Renate/cordate is the standard example of the first problem. Lewis seems to equivocate over exactly what is meant by a property. I take the example to be a powerful objection to treating properties as sets. |
| 16290 | I believe in properties, which are sets of possible individuals [Lewis] |
| Full Idea: I believe in properties. That is, I have my candidates for entities to play the role and deserve the name. My principal candidates are sets of possible individuals. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.4) | |
| A reaction: I am bewildered by any claim that a property is a 'set'. The property of being a teaspoon is just a large pile of teaspoons (one pile in each possible world)? This is the tyranny of first-order logic in philosophy. Are sets more real than properties? |
| 9653 | It would be easiest to take a property as the set of its instances [Lewis] |
| Full Idea: The simplest plan for properties is to take a property just as the set of all its instances. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: I find this a weird and counterintuitive proposal. I suppose if you think maths has been reduced to set theory, you might want to reduce everything else, and then we can all go home. I thought things were in sets because of their properties. |
| 9657 | You must accept primitive similarity to like tropes, but tropes give a good account of it [Lewis] |
| Full Idea: If you will not countenance primitive similarity in any form, then trope theory is not for you. But if you will, then duplication of tropes is an especially satisfactory form of primitive similarity to take. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: This presents the question about tropes in a beautifully simple form. Perfect similarities seem fine, but partial similarities (red and pink things) are hard, and abstract reference (pinkness and redness) is even harder. |
| 15750 | Tropes need a similarity primitive, so they cannot be used to explain similarity [Lewis] |
| Full Idea: Trope theory cannot analyse similarity, because duplication of tropes is itself a primitive relation of similarity. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: A reasonable reply to this one, I think, is that no one can explain or analyse similarity. To say that the same universal (or bunch of graded universals) is instantiated explains nothing. Maybe type-identity must be primitive in any theory? |
| 15749 | Trope theory (unlike universals) needs a primitive notion of being duplicates [Lewis] |
| Full Idea: Trope theory has the drawback that we need the primitive notion of duplicate tropes, whereas with universals we just say that it is one and the same universal through some charged particles. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: The normal term for this primitive is 'perfect resemblance', though that seems to make close resemblance a bit complicated and puzzling. I'm not sure if I understand resemblance as a feature of the world, rather than of our minds. |
| 15748 | Trope theory needs a primitive notion for what unites some tropes [Lewis] |
| Full Idea: Trope theory needs a primitive notion - 'instantion' in yet another sense - to say how the tropes that comprise a particle are united. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: Any theory which says that objects are just 'bundles' of tropes is asking for trouble. But if you say (with Lowe and others) that tropes are 'modes' of existing entities, you still have to give an account of the entity. |
| 15745 | Universals recur, are multiply located, wholly present, make things overlap, and are held in common [Lewis] |
| Full Idea: One and the same universal recurs; it is multiply located; it is wholly present in both instances, a shared common part whereby the two instances overlap. Being alike by sharing a universal is 'having something in common' in an absolutely literal sense. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: A helpful spelling out of the commitment involved (in Armstrong and others) in belief in universals. To me this is a convenient list of reasons why the whole proposal is nonsense. Why does Lewis take them seriously? |
| 15746 | If particles were just made of universals, similar particles would be the same particle [Lewis] |
| Full Idea: We cannot say that a particle is composed entirely of its several universals, because then another particle exactly like it would have the very same universals, and yet the two particles would not be the same. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: This is an argument either (implausibly) for haecceities or characterless substrata, or else for tropes (which are all separate, unlike universals). Particles as bundles of universals is not a theory I take seriously. |
| 15747 | Universals aren't parts of things, because that relationship is transitive, and universals need not be [Lewis] |
| Full Idea: It cannot be said that a universal is instantiated by anything that has it as a part, since the relation of part to whole is transitive. If charge is part of a particle, which is part of an atom, then charge is part of the atom, but an atom isn't charged. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: Given the total mystery involved in 'instantiation', it wouldn't surprise me if someone appealed to the part-whole relation, but all moves to explain instantiation are desperate. Make it a primitive, if you must, then tiptoe away. |
| 23466 | Objects are the substance of the world [Wittgenstein] |
| Full Idea: Objects make up the substance of the world. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.021) | |
| A reaction: He doesn't say here that the objects are physical, and may be including Frege's abstract objects. His concept of substance seems more like Spinoza than Aristotle. |
| 23467 | Objects are simple [Wittgenstein] |
| Full Idea: Objects are simple | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.02) | |
| A reaction: Presumably all his objects are 'simples', and what we think of as normal objects are counted by LW as 'facts'. |
| 13128 | 'Ultimate sortals' cannot explain ontological categories [Westerhoff on Wiggins] |
| Full Idea: 'Ultimate sortals' are said to be non-subordinated, disjoint from one another, and uniquely paired with each object. Because of this, the ultimate sortal cannot be a satisfactory explication of the notion of an ontological category. | |
| From: comment on David Wiggins (Identity and Spatio-Temporal Continuity [1971], p.75) by Jan Westerhoff - Ontological Categories §26 | |
| A reaction: My strong intuitions are that Wiggins is plain wrong, and Westerhoff gives the most promising reasons for my intuition. The simplest point is that objects can obviously belong to more than one category. |
| 23468 | Apart from the facts, there is only substance [Wittgenstein] |
| Full Idea: Substance is what remains independently of what is the case. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.024) | |
| A reaction: He sees what is the case as comprised of objects, so substance is even more basic. It seems close to Spinoza's single-substance view. |
| 9667 | Mereological composition is unrestricted: any class of things has a mereological sum [Lewis] |
| Full Idea: I claim that mereological composition is unrestricted: any old class of things has a mereological sum. Whenever there are some things, even out of different possible worlds, there is something composed of just those things. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.3) | |
| A reaction: To say the least, a rather unusual usage for the English word 'thing'. I presume that Lewis is in the grip of a slippery slope problem - that there is no way to define the borderline between things and non-things. Presumably 'class' is unrestricted too. |
| 13268 | There are no restrictions on composition, because they would be vague, and composition can't be vague [Lewis, by Sider] |
| Full Idea: Lewis says that if not every class has a fusion then there must be a restriction on composition. The only plausible restrictions would be vague ones, which is impossible, because then whether composition occurs would be vague. So every class has a fusion. | |
| From: report of David Lewis (On the Plurality of Worlds [1986], p.212-3) by Theodore Sider - Four Dimensionalism 9.1 | |
| A reaction: This is Lewis's key argument in favour of unrestricted composition, his Vagueness Argument. Why can't composition be vague? If you gradually reassemble a broken mirror, at what point does the mirror acquire its unity? |
| 13793 | An essential property is one possessed by all counterparts [Lewis, by Elder] |
| Full Idea: For Lewis, if a property possessed by a given individual or kind is missing in some of the contextually relevant counterparts, that property is accidental to the individual or kind; if it is possessed by all of them, that property is essential. | |
| From: report of David Lewis (On the Plurality of Worlds [1986], 248-263) by Crawford L. Elder - Real Natures and Familiar Objects 1.4 | |
| A reaction: This is a sophisticated version of the idea that essential properties are just necessary properties. It might make sense with a very sparse view of properties (mainly causal ones), but I think of essences as quite different from necessities. |
| 22321 | To know an object we must know the form and content of its internal properties [Wittgenstein, by Potter] |
| Full Idea: Wittgenstein explicitly said that to know an object I must know all its internal properties. ...Internal properties have form and content; form is 'possibility of occurrence in atomic facts' (2.0141), content is its being that specific object (2.0233). | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.01231) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 52 'Simp' | |
| A reaction: [check original quote] This seems to be an essentialist view of (formal) objects. See Potter 347-9 for discussion. The 'external properties' of an object are the atomic facts in which it occurs. |
| 9663 | A thing 'perdures' if it has separate temporal parts, and 'endures' if it is wholly present at different times [Lewis] |
| Full Idea: Something 'perdures' iff it persists by having different temporal parts, or stages, at different times, though no one part of it is wholly present at more than one time; whereas it 'endures' iff it persists by being wholly present at more than one time. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.2) | |
| A reaction: Only a philosopher would come up with a concept like perdurance. I'm thinking about this one, and will get back to you in a later-numbered idea... He compares perdurance to the way a road persists through space. |
| 14737 | Properties cannot be relations to times, if there are temporary properties which are intrinsic [Lewis, by Sider] |
| Full Idea: The problem of 'temporary intrinsics' is that in one model we think of properties as relations to times (I am 'bent' relative to now), but change sometime involves intrinsic properties. I am just plain bent, not bent with respect to something else. | |
| From: report of David Lewis (On the Plurality of Worlds [1986], p.202-4) by Theodore Sider - Four Dimensionalism | |
| A reaction: [I've compressed Sider's summary] The question of whether intrinsic properties endure over time runs in parallel with the question of whether objects endure over time, and the two issues cannot be separated. |
| 9664 | Endurance is the wrong account, because things change intrinsic properties like shape [Lewis] |
| Full Idea: The principal and decisive objection to endurance, as an account of the persistence of ordinary things, is the problem of temporary intrinsics. Persisting things change their intrinsic properties, such as their shape. My own shape keeps changing. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.2) | |
| A reaction: Presumably if something was going to endure through time it would need a shape. If it has no particular shape, it lacks identity? Lewis discusses the problem at length. Why is a precise shape essential to anything? |
| 9665 | There are three responses to the problem that intrinsic shapes do not endure [Lewis] |
| Full Idea: The problem for the endurance view of temporary intrinsic properties like shape is met be either saying shape is a disguised relational property, or only present properties are intrinsic, or the shapes belong to different things (perdurance). | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.2) | |
| A reaction: [compressed] It is certainly implausible to deny that shape is a feature of all physical objects. Or it appears to be. Shapes are hard to pin down at the quantum level. How do you sharply divide moments for the perdurance view? ... |
| 19280 | I can ask questions which create a context in which origin ceases to be essential [Lewis] |
| Full Idea: If I ask how things would be if Saul Kripke had come from no sperm and egg, but was brought by a stork, that makes sense. I create a context that makes my question make sense, which is a context that makes origin not to be essential. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.5) | |
| A reaction: I'm not clear why delivery by a stork doesn't just count as a different origin, and hence it turns out to be essential to Kripke. If Kripke were a necessary being (and he's a good candidate), then he would have no origin. |
| 6056 | Identity is not a relation between objects [Wittgenstein] |
| Full Idea: It is self-evident that identity is not a relation between objects. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5301) | |
| A reaction: Part of Wittgenstein's claim that identity statements are 'pseudo-propositions'. See, in reply, the ideas of McGinn on identity. This was part of the drive that led to the extremes of logical positivism, killing metaphysics for two generations. |
| 22322 | You can't define identity by same predicates, because two objects with same predicates is assertable [Wittgenstein] |
| Full Idea: Russell's definition of identity [x is y if any predicate of x is a predicate of y] won't do, because then one cannot say that two objects have all their properties in common | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5302), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 53 'Ident' | |
| A reaction: [The Russell is in Principia] Good. Even if Leibniz is right that no two obejcts have identical properties, it is at least meaningful to consider the possibility. Russell makes it an impossibility, rather than a contingent fact. |
| 6057 | Two things can't be identical, and self-identity is an empty concept [Wittgenstein] |
| Full Idea: Roughly speaking, to say of two things that they are identical is nonsense, and to say of one thing that it is identical with itself is to say nothing at all. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5303) | |
| A reaction: Wittgenstein's attack on identity. It is best (following McGinn) to only speak of resemblance between two things (possibly to a very high degree, as in two electrons). Self-identity just is identity; you can drop the word 'identity', but not the concept. |
| 15968 | Identity is simple - absolutely everything is self-identical, and nothing is identical to another thing [Lewis] |
| Full Idea: Identity is utterly simple and unproblematic. Everything is identical to itself; nothing is ever identical to anything except itself. There is never any problem about what makes something identical to itself; nothing can ever fail to be. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.1) | |
| A reaction: I have great problems with expressing this concept as a thing being 'identical to itself'. I will always say that it 'has an identity'. But then it is problematical, because what constitutes an identity? When do dispersing clouds lose it? |
| 15969 | Two things can never be identical, so there is no problem [Lewis] |
| Full Idea: There is never any problem about what makes two things identical; two things can never be identical. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.1) | |
| A reaction: This expresses Lewis's preference for usage of the word 'identity', rather than a simple solution. It pays no attention to type-identity, which is an obvious phenomenon. In some sense, it is just obvious that two electrons are 'identical'. |
| 9442 | The only necessity is logical necessity [Wittgenstein] |
| Full Idea: The only necessity that exists is logical necessity. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.37) | |
| A reaction: For Wittgenstein that will mean conventional necessity. He is taking a standard Humean view of these things. |
| 23495 | The tautologies of logic show the logic of language and the world [Wittgenstein] |
| Full Idea: The fact that the propositions of logic are tautologies shows the formal - logical - properties of language and the world. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.12) | |
| A reaction: This seems to me an extraordinarily hubristic remark (philosophically speaking), especially coming from a work which famously throws away its own ladder. He is very much pursuing Kant's project. |
| 23487 | What is thinkable is possible [Wittgenstein] |
| Full Idea: What is thinkable is possible too. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 3.02) | |
| A reaction: [Plucked from a context!] The modern tide has turned against this idea. The more clearly you understand the facts, the more restricted the possibilities become. If you think the impossible is possible, it is because you are bad at thinking. |
| 9660 | The impossible can be imagined as long as it is a bit vague [Lewis] |
| Full Idea: Imaginability is a poor criterion of possibility. We can imagine the impossible provided we do not imagine it in perfect detail and all the time. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.8) | |
| A reaction: In general I agree, but Williamson nicely opposes this view. The fact is that we derive most of our understanding of what is possible from imagination. We just have to realise that we can get it wrong, and so must attend to detail. |
| 23470 | Each thing is in a space of possible facts [Wittgenstein] |
| Full Idea: Each thing is, as it were, in a space of possible states of affairs. This space I can imagine as empty, but not of the thing without the space. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.013) | |
| A reaction: A clear echo of Kant on natural space. LW calls it 'logical space' (1.13). I take this to be exactly the concept of the space of possibilities which contains the modern notion of possible worlds. |
| 9669 | There are no free-floating possibilia; they have mates in a world, giving them extrinsic properties [Lewis] |
| Full Idea: There are no free-floating possibilia. Every possibility is part of a world - exactly one world - and thus comes surrounded by worldmates, and fully equipped with extrinsic properties in virtue of its relations to them. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.4) | |
| A reaction: This is a key claim in the possible worlds understanding of modality, contrary to the more common sense and normal language claim that a possibility is an isolated thing. |
| 16133 | Possible worlds can contain contradictions if such worlds are seen as fictions [Lewis] |
| Full Idea: If worlds were like stories or story-tellers, there would indeed be room for worlds according to which contradictions are true. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.2 n3) | |
| A reaction: Most existing fictions contain tiny contradictions, but we might ask whether that thereby disqualifies them from depicting genuinely 'possible' worlds. |
| 16132 | On mountains or in worlds, reporting contradictions is contradictory, so no such truths can be reported [Lewis] |
| Full Idea: To tell the alleged truth about contradictory things that happen on a mountain is just contradicting yourself, but you can't tell the truth by contradicting yourself. There is no mountain where contradictions are true, and impossible worlds are no better. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.2 n3) | |
| A reaction: [compressed] He says this works for any 'restricted' domain like a mountain or a real world, but that it wouldn't apply in an unrestricted fictional world. |
| 16283 | For me, all worlds are equal, with each being actual relative to itself [Lewis] |
| Full Idea: For me, all the worlds are on an equal footing in that each is actual relative to itself and none is actual relative to any other. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.1) | |
| A reaction: Lewis says the world we call 'actual' is simply a matter of how our indexicals refer. That sounds the wrong way round to me (as so often with Lewis). |
| 12255 | For Lewis there is no real possibility, since all possibilities are actual [Oderberg on Lewis] |
| Full Idea: Lewis-style modal realism eliminates all real possibility since on his account everything is actual relative to its own world. | |
| From: comment on David Lewis (On the Plurality of Worlds [1986]) by David S. Oderberg - Real Essentialism 6.2 | |
| A reaction: Since it is possible for me to be in New York and in Chicago, but not both at once, his possibilities have to be kept apart, even though they are actual. I expect my visit to Chicago to remain as only a possibility. |
| 9219 | Lewis posits possible worlds just as Quine says that physics needs numbers and sets [Lewis, by Sider] |
| Full Idea: Lewis's argument for possible worlds parallels Quine's for the existence of sets: our best overall empirical theory, mathematical physics, quantifies over real numbers, so we have reason to posit real numbers, or the sets to which they may be reduced. | |
| From: report of David Lewis (On the Plurality of Worlds [1986]) by Theodore Sider - Reductive Theories of Modality 3.6 | |
| A reaction: They both strike me as suspect. Indeed, the extreme implausibility of Lewis's conclusion throws doubt on Quine's original strategy. I'm happy to work with sets and possible worlds, and only worry about ontological commitment at a later stage. |
| 15022 | If possible worlds really exist, then they are part of actuality [Sider on Lewis] |
| Full Idea: The familiar complaint against Lewis is that if his worlds existed, they'd be part of actuality. | |
| From: comment on David Lewis (On the Plurality of Worlds [1986]) by Theodore Sider - Writing the Book of the World 11.5 | |
| A reaction: Sider presents that as rather superficial, but it sounds a pretty good objection to me. Lewis would note that only our world has the indexical features which he says pick out actuality. Real possible worlds might lack indexical features? |
| 10469 | A world is a maximal mereological sum of spatiotemporally interrelated things [Lewis] |
| Full Idea: A world is a maximal mereological sum of spatiotemporally interrelated things. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.6) | |
| A reaction: (I wonder what Lewis's account of space was?) A mereological sum is "the least inclusive thing that includes all the parts" (p.69). It is maximal when all 'worldmates' are parts. But then 'worldmates' are defined as parts, so it threatens circularity. |
| 16441 | Lewis rejects actualism because he identifies properties with sets [Lewis, by Stalnaker] |
| Full Idea: It is the identification of properties with sets that rules out, for Lewis, an actualist account of possible worlds. | |
| From: report of David Lewis (On the Plurality of Worlds [1986]) by Robert C. Stalnaker - Mere Possibilities 1.1 | |
| A reaction: I suppose the sets which are the properties have to include all the possible red things as well as the actual one. This escapes the renate/cordate problem. |
| 16282 | Ersatzers say we have one world, and abstract representations of how it might have been [Lewis] |
| Full Idea: The ersatzers say that instead of an incredible plurality of concrete worlds, we can have one world only, and countless abstract entities representing ways that this world might have been. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.1) | |
| A reaction: Put me down as an ersatzer. They seem to be the same as Actualists. Are worlds other possible worlds, or ways 'this world might have been'? Not the same. Does actuality constrain what is possible? (Barcan formula?) |
| 16284 | Ersatz worlds represent either through language, or by models, or magically [Lewis] |
| Full Idea: I distinguish three principal ways ersatz worlds represent: linguistic, in which they are like stories or theories; pictorial, like pictures or isomorphic scale models; or magical, in which it is just their nature to represent. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.1) | |
| A reaction: I think I incline to the 'model' view. The linguistic version means animals can't assess possibilities. I take modelling to be basic to what a mind is, and what a mind is for. |
| 23507 | Unlike the modern view of a set of worlds, Wittgenstein thinks of a structured manifold of them [Wittgenstein, by White,RM] |
| Full Idea: In 'Tractatus' Wittgenstein is not just thinking of a set of possible worlds (in the modern account), but of a structured manifold within which each 'possible world' is located. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Roger M. White - Wittgenstein's 'Tractatus Logico-Philosophicus' 3 'Positions' | |
| A reaction: So the modern view has the neutrality of a merely formal system, but LW is thinking of them as the modal structure of reality. |
| 23469 | An imagined world must have something in common with the real world [Wittgenstein] |
| Full Idea: It is obvious that an imagined world, however different it may be from the real one, must have something - a form - in common with it. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.022) | |
| A reaction: It is clear that Wittgenstein had a concept of possible worlds close to the modern view. |
| 16286 | Linguistic possible worlds need a complete supply of unique names for each thing [Lewis] |
| Full Idea: There are two difficulties with Carnap's taking possible worlds as linguistic. Everything must have a name, or our state-descriptions will be silent about nameless things, and nothing may have two names, or we may affirm and deny a predicate of one thing. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.2) | |
| A reaction: The idea of possible worlds as linguistic has no appeal for me, so this problem doesn't surprise or bother me, but it sounds fairly terminal for the project. |
| 16287 | Maximal consistency for a world seems a modal distinction, concerning what could be true together [Lewis] |
| Full Idea: An ersatz world must be maximally consistent (hence destroyed by an additional sentences), …but that is prima facie a modal distinction: a set of sentences is consistent iff those sentences, as interpreted, could all be true together. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.2) | |
| A reaction: This is indicative of Lewis's motivation for his project, which is to eliminate modal facts from the world. Only a vast multitude of non-modal concrete worlds can satisfy all the contraints. Cf many-worlds quantum mechanics for non-locality. |
| 9662 | Linguistic possible worlds have problems of inconsistencies, no indiscernibles, and vocabulary [Lewis] |
| Full Idea: Linguistic representations of possible worlds have three problems: some descriptions are inconsistent (which worlds cannot be); we cannot have indiscernible descriptions (though some worlds might be so); and descriptions are limited by vocabulary. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.2) | |
| A reaction: Lewis is wonderful at getting problems clearly on the table. I take the idea of possible worlds as linguistic entities to be a non-starter, because (as usual) animals do it too, when they think of possibilities, which even the dimmest ones must do. |
| 7690 | If sets exist, then defining worlds as proposition sets implies an odd distinction between existing and actual [Jacquette on Lewis] |
| Full Idea: If sets exist, then the conventional concept of a logically possible world as a proposition set requires a counterintuitive distinction between existence and actuality, between what exists and what is actual. | |
| From: comment on David Lewis (On the Plurality of Worlds [1986]) by Dale Jacquette - Ontology Ch.2 | |
| A reaction: This pinpoints the obvious difficulty that most people have with Lewis's claim that possible worlds exist. Russell's claim that universals 'subsist' (Idea 5409) is a similar attempt to have two different sorts of existence in your ontology. |
| 11027 | To know an object you must know all its possible occurrences [Wittgenstein] |
| Full Idea: If I know an object I also know all its possible occurrences in states of affairs. (Every one of those possibilities must be part of the nature of the object.) A new possibility cannot be discovered later. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0123) | |
| A reaction: The requirement that you know them 'all' seems absurd, especially if we need science to discover them. I take this idea to be extremely important, and essentially Aristotelian (connecting with the notion of 'potentiality'). We need to know the powers. |
| 23465 | The 'form' of an object is its possible roles in facts [Wittgenstein] |
| Full Idea: The possibility of its occurrence in atomic facts is the form of the object. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0141) | |
| A reaction: Morris says this picks up the idea from Kant. We might now label the 'form' as the 'modal profile' of the object (a phrase I like). The modern issues over transworld identity seem to be a development of this thought. |
| 14404 | The counterpart relation is sortal-relative, so objects need not be a certain way [Lewis, by Merricks] |
| Full Idea: Lewis takes the counterpart relation to be sortal-relative, so he (no less than Quine) denies that objects, qua existing, are necessarily a certain way. | |
| From: report of David Lewis (On the Plurality of Worlds [1986]) by Trenton Merricks - Truth and Ontology 5.III n10 | |
| A reaction: Does this mean that there could be two different versions of the same possible world (certainly not!), or that worlds are entirely created by our concepts rather than by what is actually possible. |
| 5440 | A counterpart in a possible world is sufficiently similar, and more similar than anything else [Lewis, by Mautner] |
| Full Idea: 'Jack could have been taller' implies a different Jack in a different world, so Lewis defines a counterpart in a possible world as an individual sufficiently similar to Jack, and more similar to Jack than anything else in that world. | |
| From: report of David Lewis (On the Plurality of Worlds [1986]) by Thomas Mautner - Penguin Dictionary of Philosophy p.115 | |
| A reaction: If we say something like "I could have been twins" or "I could have been a genius" in another world, it would need an odd concept of my personal identity for it to remain identical in those counterfactual situations. Lewis has a point. |
| 5441 | Why should statements about what my 'counterpart' could have done interest me? [Mautner on Lewis] |
| Full Idea: If I only have counterparts in possible worlds who are not identical to me, statements about what I could have done will seem irrelevant to me, because they will be about someone else. | |
| From: comment on David Lewis (On the Plurality of Worlds [1986]) by Thomas Mautner - Penguin Dictionary of Philosophy p.115 | |
| A reaction: We might rephrase the statement as "I could have been the person who did x". Presumably my counterpart is not just any stranger, but someone I could have been. "I could have been a brick" - now that seems irrelevant to me! |
| 16291 | In counterpart theory 'Humphrey' doesn't name one being, but a mereological sum of many beings [Lewis] |
| Full Idea: For the counterpart theorist, the trick is to say that 'Humphrey' names not the Humphrey of our world, and not the Humphrey of another, but rather the trans-world individual who is the mereological sum of all those local Humphreys. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.1) | |
| A reaction: On Lewis's perdurantism Humphrey is a 'spacetime worm' across his lifetime. Now we are adding all the possible Humphreys to the sum. I'm losing track of Humphrey's shape. |
| 12869 | Two objects may only differ in being different [Wittgenstein] |
| Full Idea: If two objects have the same logical form, the only distinction between them, apart from their external properties, is that they are different. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0233) | |
| A reaction: This isn't a commitment to haecceities, but it seems to be flirting with the idea. See Simons 1987:241. Kit Fine picks up the idea that objects, as well as sentences, might have 'logical form'. How can being 'different' be primitive? Spatial location? |
| 11903 | Extreme haecceitists could say I might have been a poached egg, but it is too remote to consider [Lewis, by Mackie,P] |
| Full Idea: Lewis's strategy for defending extreme haecceitism is that supposed impossibilities (that I might have been a poached egg) could be reconstrued as genuine possibilities that are so remote from reality that they are ignored. | |
| From: report of David Lewis (On the Plurality of Worlds [1986], 239-) by Penelope Mackie - How Things Might Have Been 9.3 | |
| A reaction: Not a promising route. Wiggins asks: if you think I could have been a poached egg, start by defining more precisely this 'I' to which we are referring. The definition will blatantly exclude any possibility of my poachedegghood. |
| 15129 | Haecceitism implies de re differences but qualitative identity [Lewis] |
| Full Idea: If two worlds differ in what they represent de re concerning some individual, but do not differ qualitatively in any way, I shall call that a haecceitist difference. Haecceitism, then, says there are at least some haecceitist differences between worlds. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.4) | |
| A reaction: Lewis bases this view on Kaplan. My brief summary of this is that 'identity may be hidden'. If all electrons are different, what distinguishes them? |
| 9670 | Extreme haecceitism says you might possibly be a poached egg [Lewis] |
| Full Idea: The most extreme version of haecceitism says that anything could possibly have any qualitative character; for instance, there is a world according to which you are a poached egg. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.4) | |
| A reaction: Presumably a plausible haecceitist view would have to be combined with essentialism, given that the possibility that I might be a poached egg is beyond my intuitive grasp. |
| 23503 | Strict solipsism is pure realism, with the self as a mere point in surrounding reality [Wittgenstein] |
| Full Idea: Solipsism, when its implications are followed out strictly, coincides with pure realism. The self of solipsism shrinks to a point without extension, and there remains the reality co-ordinated with it. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.64) | |
| A reaction: Despite this, Michael Morris is more inclined to see him as an idealist. It is not clear whether the present account of solipsism is idealist or realist. Berkeley seemed to think his idealism was true realism. Can reality be co-ordinated with a point? |
| 16907 | If the truth doesn't follow from self-evidence, then self-evidence cannot justify a truth [Wittgenstein] |
| Full Idea: If the truth of a proposition does not follow from the fact that it is self-evident to us, then its self-evidence in no way justifies our belief in its truth. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.1363), quoted by Robin Jeshion - Frege's Notion of Self-Evidence 4 | |
| A reaction: Frege seems to have taken self-evidence as intrinsic justification, but Wittgenstein seems to demand a supporting inference. But what is it all based on? Stipulative definitions? |
| 23479 | The Tractatus aims to reveal the necessities, without appealing to synthetic a priori truths [Wittgenstein, by Morris,M] |
| Full Idea: We can see the 'Tractatus' as an attempt to make sense of what is necessarily true of the world - in general, and not just in the mathematical case - without appealing to synthetic a priori truths. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Michael Morris - Guidebook to Wittgenstein's Tractatus 2H | |
| A reaction: Morris sees the Tractatus as firmly in the Kantian tradition, and exploring Kant's main project in the first Critique. |
| 23501 | There is no a priori order of things [Wittgenstein] |
| Full Idea: Whatever we can describe at all could be other than it is. There is no a priori order of things. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.634) | |
| A reaction: This is his rejection of Kant's dream, of inferring truths about the world by self-examination. However, compare Idea 23495. He clings to the faith that logic reveals 'something' about reality. |
| 7088 | Logic and maths can't say anything about the world, since, as tautologies, they are consistent with all realities [Wittgenstein, by Grayling] |
| Full Idea: Neither logical nor mathematical propositions say anything about the world, because in virtue of their always being true they are consistent with any way the world could happen to be. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by A.C. Grayling - Wittgenstein Ch.2 | |
| A reaction: This became the standard view for twentieth century empiricists, and appeared to rule out a priori synthetic knowledge forever. Kripke's proposal that there are a posteriori necessities, however, changes the picture. |
| 16909 | Logic is a priori because we cannot think illogically [Wittgenstein] |
| Full Idea: That logic is a priori consists in the fact that we cannot think illogically. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.4731), quoted by Robin Jeshion - Frege's Notion of Self-Evidence 4 | |
| A reaction: A rather startling claim. Presumably we have to say that when we draw a stupid inference, then we weren't really 'thinking'? |
| 23485 | No pictures are true a priori [Wittgenstein] |
| Full Idea: There are no pictures that are true a priori. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.225) | |
| A reaction: This is part of the growing modern doubts about the scope or possibility of a priori knowledge. A 'picture' here is the mental model which is the meaning of a proposition. |
| 16279 | General causal theories of knowledge are refuted by mathematics [Lewis] |
| Full Idea: Causal accounts of knowledge are all very well in their place, but if they are put forward as general theories, then mathematics refutes them. | |
| From: David Lewis (On the Plurality of Worlds [1986], 2.4) | |
| A reaction: You might have some sort of notion of an abstraction from causation which mimicked it in the mathematics case. Lots of things seem to be 'forced' in mathematics. Call it 'ersatz causation'. Necessities are enforcers. |
| 6591 | Doubts can't exist if they are inexpressible or unanswerable [Wittgenstein] |
| Full Idea: Doubt can exist only where a question exists, a question only where an answer can exist, and an answer only where something can be said. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.51) | |
| A reaction: I don't agree with any of that. It is typical of the phase when philosophers were mesmerised by language. Cats look puzzled sometimes. A glimmering of doubt may be pre-linguistic, inexpressible and unanswerable, but still feels like a doubt. |
| 17665 | The 'Tractatus' is instrumentalist about laws of nature [Wittgenstein, by Armstrong] |
| Full Idea: Wittgenstein is an instrumentalist about laws of nature in 'Tractatus'. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by David M. Armstrong - What is a Law of Nature? 01.3 | |
| A reaction: [I record this, but don't know the reference] |
| 2941 | Induction accepts the simplest law that fits our experiences [Wittgenstein] |
| Full Idea: The procedure of induction consists in accepting as true the simplest law that can be reconciled with our experiences. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.363) |
| 9661 | Induction is just reasonable methods of inferring the unobserved from the observed [Lewis] |
| Full Idea: I use the word 'induction' broadly, to cover all the methods we deem reasonable for forming beliefs about the unobserved parts of our world on the basis of experience with the observed parts. | |
| From: David Lewis (On the Plurality of Worlds [1986], 2.5) | |
| A reaction: Good. Attempts to be precise about it seem to be hopeless and invite paradoxes. Personally I just define it as 'learning from experience', because that makes what we do continuous with the behaviour of other sensible animals. |
| 9652 | To just expect unexamined emeralds to be grue would be totally unreasonable [Lewis] |
| Full Idea: Some beliefs are just unreasonable in a strong sense. Think of the man who, for no special reason, expects unexamined emeralds to be grue. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.4) | |
| A reaction: This is a nice converse way of seeing the point that 'grue' is such an totally artificial predicate. I still say that the most illuminating point is that grue is not a colour, so seeing a grue thing is no confirmation at all. |
| 17673 | The modern worldview is based on the illusion that laws explain nature [Wittgenstein] |
| Full Idea: The whole modern conception of the world is founded on the illusion that the so-called laws of nature are the explanations of natural phenomena. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.371) | |
| A reaction: Love it! Not only does it say that lawlike explanation is wrong, but it registers that this is a profound feature of the modern view of the world, and not just a slightly misguided philosophical theory. |
| 9658 | An explanation tells us how an event was caused [Lewis] |
| Full Idea: An explanation, I think, is an account of etiology: it tells us something about how an event was caused. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: Will this cover mathematical explanations? Numbers would have to have causal powers. |
| 16280 | Often explanaton seeks fundamental laws, rather than causal histories [Lewis] |
| Full Idea: Sometimes the pursuit of explanation is more the pursuit of unified and general fundamental laws than of information about the causal histories of events. | |
| From: David Lewis (On the Plurality of Worlds [1986], 2.7) | |
| A reaction: It is hard to disagree, given the 'sometimes'. I don't think that Newton's Law of Gravity (say), with its lovely equation, actually explained anything at all about gravity. Finding the law closes the quest for an accurate description of what happens. |
| 16274 | If the well-ordering of a pack of cards was by shuffling, the explanation would make it more surprising [Lewis] |
| Full Idea: Suppose you find in a hotel room a pack of cards in exactly standard order. Not surprising - maybe it's a new deck, or someone arranged them. Not so. They got that way by being fairly shuffled. The explanation would make the explanandum more surprising. | |
| From: David Lewis (On the Plurality of Worlds [1986], 2.7) | |
| A reaction: [compressed] A lovely Lewisian example, that instantly makes big trouble for the (implausible) view that a cause is something which increases the likelihood of a thing. |
| 2940 | The subject stands outside our understanding of the world [Wittgenstein] |
| Full Idea: The subject does not belong to the world; rather, it is a limit of the world. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.632) | |
| A reaction: Interesting. We must not confuse epistemology with ontology, but the perceived world exists between two limits - the farthest reaches of my perceptions, and the farthest reaches of myself. I wish I could clearly disentangle the nearer border. Dasein? |
| 23498 | The modern idea of the subjective soul is composite, and impossible [Wittgenstein] |
| Full Idea: Therre is no such thing as the soul - the subject, etc. - as it is conceived in the superficial psychology of the present day. Indeed a composite soul would no longer be a soul. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5421) | |
| A reaction: This seems to endorse Descartes' claim about the essential unity of the mind. I think Hume is in the background of LW's thought. Presumably the psychologist offered a 'composite' view. Prior discussion of belief leads into this remark. |
| 23475 | The form of a proposition must show why nonsense is unjudgeable [Wittgenstein] |
| Full Idea: The correct explanation of the form of the proposition 'A judges p' must show that it is impossible to judge a nonsense. (Russell's theory does not satisfy this condition). | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5422) | |
| A reaction: In Notebooks p.96 LW gives the example 'this table penholders the book'. I take it Russell wanted judgement to impose unified meaning on sentences, but LW shows that assembling meaning must precede judgement. LW is right. |
| 7084 | What can be said is what can be thought, so language shows the limits of thought [Wittgenstein, by Grayling] |
| Full Idea: In Wittgenstein's view, what can be said is the same as what can be thought; so that once one has grasped the nature of language, one has shown the limit beyond which language and thought become nonsense. | |
| From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by A.C. Grayling - Wittgenstein Ch.2 | |
| A reaction: I just don't believe that what is thinkable is limited to what is expressible. A lot of philosophy is the struggle to find expression for thoughts which are just beyond the edge of current language. See Idea 6870. |
| 8901 | Abstraction is usually explained either by example, or conflation, or abstraction, or negatively [Lewis] |
| Full Idea: Abstraction is usually explained in one of four ways: the Way of Example (cf. donkeys and numbers), the Way of Conflation (same as sets), the Negative Way (non-spatial and non-causal) or the Way of Abstraction (incomplete descriptions). | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: [Compressed; a footnote dismisses Dummett's fifth way] Example has blurred boundaries, and explains nothing. Gerrymandered sets don't produce concepts. Negative accounts explain nothing. So it's the Way of Abstraction! |
| 8904 | The Way of Abstraction says an incomplete description of a concrete entity is the complete abstraction [Lewis] |
| Full Idea: The Way of Abstraction says abstract entities are abstractions from concrete entities; they result from somehow subtracting specificity, so that an incomplete description of the original concrete entity is a complete description of the abstraction. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: Defined like this, it rather looks as if abstractions would be entirely verbal - which may well be the correct situation, except that higher animals seem capable of minimal levels of abstraction. This Way is denigrated by Frege and Geach. |
| 8938 | The Way of Example compares donkeys and numbers, but what is the difference, and what are numbers? [Lewis] |
| Full Idea: The Way of Example says concrete entities are things like donkeys and puddles, but abstract entities are things like numbers. That gives us little guidance. There are no uncontroversial accounts of numbers, and donkeys and number differ in too many ways. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: That demolishes that fairly swiftly. It may be unfair to demand an agreed account of numbers, but the respect(s) in which donkeys and numbers differ needs to be spelled out before anything useful has been said. |
| 8903 | Abstracta can be causal: sets can be causes or effects; there can be universal effects; events may be sets [Lewis] |
| Full Idea: Is it true that sets or universals cannot enter into causal interaction? Why can't we say that a set of things causes something, or something causes a set of effects? Or positive charge has characteristic effects? Or an event is a sort of set? | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: This idea, and 8902, form a devastating critique of attempts to define abstraction in a purely negative way, as non-spatial and non-causal. Only a drastic revision of widely held views about sets, universals and events could save that account. |
| 8902 | If abstractions are non-spatial, then both sets and universals seem to have locations [Lewis] |
| Full Idea: If abstract entities are not located, then a set of things does seem to have a location, though perhaps a divided one; and universals, if they are wholly present in each particular, are where their instances are, so negation can't define abstraction. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: He admits that non-spatial accounts of sets and universals are possible, but the jury is out on both of them, and more cautious theories, even if they are realist, will give them both locations. A good argument. |
| 8905 | If universals or tropes are parts of things, then abstraction picks out those parts [Lewis] |
| Full Idea: A theory of non-spatiotemporal parts of things, whether recurring universals or non-recurring tropes, makes good sense of some abstractions. Unit negative charge is a universal common to particles, and an abstraction by being part of them. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: He cautiously refers to 'some' abstractions. It is one of Donald Williams's proud boasts concerning his trope theory that it will handle this problem well. I'm not sure that we should be saying that abstractions are actually concrete bits of things. |
| 8906 | If we can abstract the extrinsic relations and features of objects, abstraction isn't universals or tropes [Lewis] |
| Full Idea: Why can't we abstract a highly extrinsic aspect of something, say its surname, or its spatiotemporal location, or its role in a causal network, or its role in some body of theory? But these are unsuitable candidates for being genuine universals or tropes. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: (This is a criticism of the proposal in Idea 8905) Obviously we can abstract such things. In particular the role in a causal network is a function, which is a central example of an abstract idea. Russell keeps reminding us that relations are universals. |
| 8907 | The abstract direction of a line is the equivalence class of it and all lines parallel to it [Lewis] |
| Full Idea: We can abstract the direction of a line by taking the direction as the equivalence class of that line and all lines parallel to it. There is no subtraction of detail, but a multiplication of it; by swamping it, the specifics of the original line get lost. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: You can ask how wide a line is, but not how wide a direction is, so a detail IS being subtracted. I don't see how you can define the concept of a banana by just saying it is 'every object which is equivalent to a banana'. 'Parallel' is an abstraction. |
| 8908 | For most sets, the concept of equivalence is too artificial to explain abstraction [Lewis] |
| Full Idea: Most sets cannot be regarded as abstractions by equivalence: most sets are equivalence classes only under thoroughly artificial equivalence. (And the empty set is not an equivalence class at all). | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.7) | |
| A reaction: [Recorded for further investigation..] My intuitions certainly cry out against such a thin logical notion giving a decent explanation of such a rich activity as abstraction. |
| 16289 | We can't account for an abstraction as 'from' something if the something doesn't exist [Lewis] |
| Full Idea: We cannot really be talking about the things whence an abstraction-like entity is abstracted if there are no such things. | |
| From: David Lewis (On the Plurality of Worlds [1986], 3.3) | |
| A reaction: Sounds like a killer blow, but I don't think so. I can't think of a concept which doesn't have a possible basis in reality, assuming that it might be a complex assemblage of abstracted components. |
| 23482 | The 'form' of the picture is its possible combinations [Wittgenstein] |
| Full Idea: The form of depiction is the possibility that the things are combined with one another as are the elements of the picture. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.151) | |
| A reaction: This is why 'model' (or even 'simulation'?) is a better term than 'picture' for his proposal. Pictures are fixed, but models can be adjusted. |
| 8172 | To understand a proposition means to know what is the case if it is true [Wittgenstein] |
| Full Idea: To understand a proposition means to know what is the case if it is true. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.024) | |
| A reaction: This established the Frege truth-conditions theory of meaning, which was expanded by Davidson, and then possible worlds semantics. You can't assess truth without knowing meaning. Dummett says the two go together. |
| 7086 | Good philosophy asserts science, and demonstrates the meaninglessness of metaphysics [Wittgenstein] |
| Full Idea: The correct method in philosophy would be to say nothing except what can be said, i.e. propositions of natural science, and whenever someone wanted to say something metaphysical, to show that he had failed to give a meaning to signs in his propositions. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.53) | |
| A reaction: This seems to be the germ of logical positivism, picked up by the Vienna Circle, and passed on the Ayer and co. How, though, do you 'show' that a sign is meaningless? Very abstract ideas are too far away from experience to be analysed that way. |
| 16278 | A particular functional role is what gives content to a thought [Lewis] |
| Full Idea: Anything that is a thinker at all has a thought with a certain content in virtue of being in a state which occupies a certain functional role. | |
| From: David Lewis (On the Plurality of Worlds [1986], 2.3) | |
| A reaction: So often Lewis seems to get things the wrong way round. Maybe if you invert his entire (fabulously consistent) philosophy, you get the right answer? I take the content to be what makes the role possible. |
| 23511 | Propositions use old expressions for a new sense [Wittgenstein] |
| Full Idea: A proposition must use old expressions to communicate a new sense. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.03) | |
| A reaction: A nicely expressed affirmation of the principle of compositionality. It entails that the propositions can be either true or false, according to LW. |
| 23488 | Propositions are understood via their constituents [Wittgenstein] |
| Full Idea: A proposition is understood by anyone who understands its constituents. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.024) | |
| A reaction: The 'constituents' had better include the grammatical relationships. Otherwise it's 'rearrange these words to make a well known saying'. That said, this strikes me as an important truth about language. We assemble sentence meanings. |
| 23486 | Pictures are possible situations in logical space [Wittgenstein] |
| Full Idea: A picture represents a possible situation in logical space. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.202) | |
| A reaction: This seems pretty close to the idea that propositions are sets of possible worlds (though that seems to add unnecessary extra baggage). If they just picture situations, why does he mention logical space? Within the limits of possible picturing? |
| 9654 | A proposition is a set of entire possible worlds which instantiate a particular property [Lewis] |
| Full Idea: I identify propositions with certain properties - namely, with those that are instantiated only by entire possible worlds. Then if properties generally are the sets of their instances, a proposition is a set of possible worlds. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: I don't get this. How can the proposition that tomatoes are edible be an entire set of possible worlds? The proposition seems to be about tomatoes, and nothing else. Should we talk of 'possibilities', rather than of 'possible worlds'? |
| 15736 | A proposition is the property of being a possible world where it holds true [Lewis] |
| Full Idea: I identify propositions with properties that are instantiated only by entire possible worlds. If properties are the sets of their instances, a proposition is a set of possible worlds. A proposition is the property of being a world where it holds. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: This is so far away from my concept of a proposition (as a truth-evaluable representational mental event) that I struggle to compute it. So the proposition that I am sitting here is the property of 'being the actual world'. Eh? |
| 15738 | Propositions can't have syntactic structure if they are just sets of worlds [Lewis] |
| Full Idea: If it is central to 'proposition' that there be quasi-syntactic structure, so that there are subject-predicate, or negative, or conjunctive, or quantified propositions, then sets of possible worlds will not do. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.5) | |
| A reaction: He proposes 'more complicated set-theoretic constructions out of possibilia' instead. I am very much committed to propositions having quasi-syntactic structure. |
| 23497 | Solipsism is correct, but can only be shown, not said, by the limits of my personal language [Wittgenstein] |
| Full Idea: What the solipsist means is quite correct; only it cannot be said, but makes itself manifest. The world is my world: this is manifest in the fact that the limits of language (of that language which I alone understand) mean the limits of my world. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.62) | |
| A reaction: I take it that LW later showed that the remark in brackets is absurd, using his Private Language argument. Commentators seem unclear about how seriously to take this claim. |
| 23489 | We translate by means of proposition constituents, not by whole propositions [Wittgenstein] |
| Full Idea: When translating one language into another, we do not proceed by translating each proposition of the one into a proposition of the other, but merely by translating the constituents of propositions. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.025) | |
| A reaction: This seems opposed to Quine's later holistic view of translating whole languages. Is he objecting to Frege's context principle? |
| 2943 | Ethics cannot be put into words [Wittgenstein] |
| Full Idea: Ethics cannot be put into words. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.421) | |
| A reaction: Nonsense. There is lots of good writing about ethics. This is evasive mysticism. |
| 2942 | The sense of the world must lie outside the world [Wittgenstein] |
| Full Idea: The sense of the world must lie outside the world. | |
| From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.41) | |
| A reaction: Since I don't believe that anything 'lies outside the world' I can't make sense of this. He implies that the Self lies outside of the world (to the point of solipsism), so I suppose that's it. |
| 9659 | Causation is when at the closest world without the cause, there is no effect either [Lewis] |
| Full Idea: If it is the case at world W that if event C had not occurred, E would not have occurred either, then the counterfactual means that at the closest worlds to W at which C does not occur, E does not occur either. | |
| From: David Lewis (On the Plurality of Worlds [1986], 1.6) | |
| A reaction: This is a very Humean account, though updated, which sees nothing more to causation than transworld regularities. To me that is just describing the evidence for causation, not giving an account of it (even if the latter is impossible). |
| 9666 | It is quite implausible that the future is unreal, as that would terminate everything [Lewis] |
| Full Idea: It is hard to believe that any philosopher means it when they say the future is unreal. If anyone is right that there is no future, that moment is their last, and it is the end of everything. | |
| From: David Lewis (On the Plurality of Worlds [1986], 4.2) | |
| A reaction: A bit simplistic. I might say 'there will be a future time, but it doesn't exist now'. That's the peculiar thing about time. If I say New York doesn't exist, then clearly I can't visit it. The London 2012 Olympic Stadium is going to exist. |