47 ideas
| 8605 | In addition to analysis of a concept, one can deny it, or accept it as primitive [Lewis] |
| Full Idea: There are three ways to give an account: 1) 'I deny it' - this earns a failing mark if the fact is really Moorean. 2) 'I analyse it thus'. 3) 'I accept it as primitive'. Not every account is an analysis. | |
| From: David Lewis (New work for a theory of universals [1983], '1 Ov Many') | |
| A reaction: I prefer Shoemaker's view (Idea 8559). Personally I think 1) should be employed more often than it is (it is a very misunderstood approach). 3) has been overused in recent years (e.g. by Davidson and McGinn). |
| 21110 | An understanding of the most basic physics should explain all of the subject's mysteries [Krauss] |
| Full Idea: Once we understood the fundamental laws that govern forces of nature at its smallest scales, all of these current mysteries would be revealed as natural consequences of these laws. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 08) | |
| A reaction: This expresses the reductionist view within physics itself. Krauss says the discovery that empty space itself contains energy has led to a revision of this view (because that is not part of the forces and particles studied in basic physics). |
| 8607 | Supervenience is reduction without existence denials, ontological priorities, or translatability [Lewis] |
| Full Idea: Supervenience is a stripped down form of reductionism, unencumbered by dubious denials of existence, claims of ontological priority, or claims of translatability. | |
| From: David Lewis (New work for a theory of universals [1983], 'Dup,Sup,Div') | |
| A reaction: Interesting. It implies that the honest reductionist (i.e. me) should begin by asserting supervience, and only at a second stage go on to deny a bit of existence, loudly affirm priorities, and offer translations. Honest toil. |
| 8606 | A supervenience thesis is a denial of independent variation [Lewis] |
| Full Idea: A supervenience thesis is a denial of independent variation. | |
| From: David Lewis (New work for a theory of universals [1983], 'Dup,Sup,Div') | |
| A reaction: Not everyone agrees on this. This says if either A or B change, the change is reflected in the other one. But the other view is of one-way dependence. A only changes if B changes, but B can also make changes that don't affect A. |
| 21105 | In 1676 it was discovered that water is teeming with life [Krauss] |
| Full Idea: Van Leeuwenhoek first stared at a drop of seemingly empty water with a microscope in 1676 and discovered in was teeming with life. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 04) | |
| A reaction: I am convinced that this had a huge influence on Leibniz's concept of monads. He immediately became convinced that it was some sort of life all the way down. He would be have been disappointed by the subsequent chemical reduction of life. |
| 8580 | Materialism is (roughly) that two worlds cannot differ without differing physically [Lewis] |
| Full Idea: Final definition of 'Materialism': Among worlds where no natural properties alien to our world are instantiated, no two differ without differing physically; and two such worlds that are exactly alike physically are duplicates. | |
| From: David Lewis (New work for a theory of universals [1983], 'Min Mat') | |
| A reaction: This would presumably allow for an anomalous monist/property dualist view of mind, but not full dualism. But if there are no psychophysical laws, what stops the mental changing while the physical remains the same? |
| 8571 | Universals are wholly present in their instances, whereas properties are spread around [Lewis] |
| Full Idea: Universals and properties are different because a universal is supposed to be wholly present wherever it is instantiated. A property, by contrast, is spread around. The property of being a donkey is partly present wherever there is a donkey. | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop') | |
| A reaction: No mention of tropes. The claim that universals are widespread, and yet must be instantiated, is dealt with by Lewis's commitment to the existence of possible donkeys. |
| 10717 | Natural properties figure in the analysis of similarity in intrinsic respects [Lewis, by Oliver] |
| Full Idea: Lewis argues that there are natural properties, which makes various analyses possible, especially of similarity in intrinsic respects. Naturalness comes in degrees, with perfectly natural properties being the limiting case. | |
| From: report of David Lewis (New work for a theory of universals [1983]) by Alex Oliver - The Metaphysics of Properties 4 | |
| A reaction: This sounds to be the wrong way round. We don't start with similarities and work back to natural properties. We encounter natural properties (through their causal action), and these give rise to the similarities. |
| 16217 | Lewisian natural properties fix reference of predicates, through a principle of charity [Lewis, by Hawley] |
| Full Idea: For Lewis natural properties are important for their role in making language and thought determinate: principles of charity or humanity tell us to attribute natural properties to predicates wherever possible, break underdetermination of their reference. | |
| From: report of David Lewis (New work for a theory of universals [1983]) by Katherine Hawley - How Things Persist 3.8 | |
| A reaction: Lewis always seems to find reasons in semantics or logic for his metaphysics, instead of in the science. Lewis ends up with 'folk' natural properties, instead of accurate ones. |
| 8613 | Objects are demarcated by density and chemistry, and natural properties belong in what is well demarcated [Lewis] |
| Full Idea: Where my cat (Bruce) ends, there the density of matter, the relative abundance of chemical elements, abruptly change. Bruce is also a locus of causal chains, which traces back to natural properties. Natural properties belong to well demarcated things. | |
| From: David Lewis (New work for a theory of universals [1983], 'Cont of L') | |
| A reaction: This is an amazingly convoluted way to define natural properties in terms of the classes they generate, but it seems obvious to me that the properties are logically prior to the classes. |
| 8585 | Reference partly concerns thought and language, partly eligibility of referent by natural properties [Lewis] |
| Full Idea: Reference consists in part of what we do in language or thought when we refer, but in part it consists in eligibility of the referent. And this eligibility to be referred to is a matter of natural properties. | |
| From: David Lewis (New work for a theory of universals [1983], 'Cont of L') | |
| A reaction: This is a surprising conclusion for Lewis to reach, having started from properties as any old set members (see Idea 8572). There are references to intentional objects, such as 'there should have been someone on duty'. |
| 8586 | Natural properties tend to belong to well-demarcated things, typically loci of causal chains [Lewis] |
| Full Idea: One thing that makes for naturalness of a property is that it is a property belonging exclusively to well-demarcated things (like my cat Bruce, who is a locus of causal chains). | |
| From: David Lewis (New work for a theory of universals [1983], 'Cont of L') | |
| A reaction: Compare Idea 8557. Well-demarcated things may also have gerrymandered properties that are parts of 'arbitrary Boolean compounds' (Lewis). Why not make use of the causal chains to identify the properties? |
| 8589 | For us, a property being natural is just an aspect of its featuring in the contents of our attitudes [Lewis] |
| Full Idea: The reason natural properties feature in the contents of our attitudes is that naturalness is part of what it is to feature therein. We aren't built to take a special interest in natural properties, or that we call them natural if they are interesting. | |
| From: David Lewis (New work for a theory of universals [1983], 'Cont of L') | |
| A reaction: Evolution never features in Lewis's metaphysics. I would have thought we were very much built to focus on natural properties. This sounds odd, and gives no help in distinguishing natural properties from all our other daft contents. |
| 15460 | All perfectly natural properties are intrinsic [Lewis, by Lewis] |
| Full Idea: Lewis proposed that all perfectly natural properties are intrinsic. | |
| From: report of David Lewis (New work for a theory of universals [1983], p.355-7) by David Lewis - Defining 'Intrinsic' (with Rae Langton) IX | |
| A reaction: Depends what you mean by 'natural', 'property' and 'intrinsic'! Presumably there are natural extrinsic facts, in naturally necessary relationships. If all natural properties are powers, they would have to be intrinsic. Extrinsics would be derivative. |
| 15726 | Natural properties fix resemblance and powers, and are picked out by universals [Lewis] |
| Full Idea: Perhaps we could call a property 'perfectly' natural if its members are all and only those things that share some one universal, ...where the natural properties would be the ones whose sharing makes for resemblance, and the ones relevant to causal powers. | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop') | |
| A reaction: This is Lewis fishing for an account of properties that does a bit better than the mere recourse to set theory (which he intuitively favours) seems to do. He remains neutral about the ontological status of a universal (though he prefers nominalism). |
| 7031 | Lewis says properties are sets of actual and possible objects [Lewis, by Heil] |
| Full Idea: David Lewis has produced an important theory of properties as sets of actual and possible objects. | |
| From: report of David Lewis (New work for a theory of universals [1983]) by John Heil - From an Ontological Point of View §12.2 | |
| A reaction: The notion that a property is an 'object' sounds wrong, as it is too passive. It also seems to allow for the possibility of uninstantiated properties existing, where properties are presumably always 'of' something. |
| 8572 | Any class of things is a property, no matter how whimsical or irrelevant [Lewis] |
| Full Idea: Any class of things, be it ever so gerrymandered and miscellaneous and indescribable in thought and language, and be it ever so superfluous in characterizing the world, is nevertheless a property. | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop') | |
| A reaction: I much prefer, at the very least, the sparse approach of Armstrong, and in fact would vote for Shoemaker's highly physical view. Lewis proceeds after this to try to pick out the properties that really matter. |
| 18433 | There are far more properties than any brain could ever encodify [Lewis] |
| Full Idea: There are so many properties that those specifiable in English, or in the brain's language of synaptic interconnections and neural spikes, could only be an infinitesimal minority. | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop') | |
| A reaction: Thus there are innumerable properties that must lack predicates. But there are also innumerable predicates that correspond to no real properties. I conclude that properties and predicates have very little in common. Job done. |
| 8604 | We need properties as semantic values for linguistic expressions [Lewis] |
| Full Idea: We need properties, sometimes natural and sometimes not, to provide an adequate supply of semantic values for linguistic expressions. | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop') | |
| A reaction: A characteristically twentieth century approach, which I find puzzling. We don't need a Loch Ness Monster in order to use the term 'Loch Ness Monster'. Lewis appears to have been a pupil of Quine... He was not, though, a Predicate Nominalist. |
| 14499 | Properties are classes of possible and actual concrete particulars [Lewis, by Koslicki] |
| Full Idea: Lewis has a preference for a nominalist conception of properties as classes of possible and actual concrete particulars. | |
| From: report of David Lewis (New work for a theory of universals [1983]) by Kathrin Koslicki - The Structure of Objects II.3 | |
| A reaction: I'm sympathetic to nominalism, but still can't swallow the idea that a property like redness is nothing more than a collection of particulars, the red things. This class will include all sorts of non-red features. |
| 15120 | Lewisian properties have powers because of their relationships to other properties [Lewis, by Hawthorne] |
| Full Idea: According to Lewis's conception, the causal powers of a property are constituted by its patterned relations to other properties in the particular Humean mosaic that is the actual world. | |
| From: report of David Lewis (New work for a theory of universals [1983]) by John Hawthorne - Causal Structuralism Intro | |
| A reaction: I just can't grasp this as a serious proposal. Relations cannot be the bottom line in explanation of the world. What are the relata? I take powers to be primitive. |
| 8573 | Most properties are causally irrelevant, and we can't spot the relevant ones. [Lewis] |
| Full Idea: Properties do nothing to capture the causal powers of things. Almost all properties are causally irrelevant, and there is nothing to make the relevant ones stand out from the crowd. | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop') | |
| A reaction: Shoemaker, who endorses a causal account of properties, has a go at this problem in Idea 8557. The property of being massive is more likely to be causal than existing fifty years after D-Day. Lewis attempts later to address the problem. |
| 8569 | I suspend judgements about universals, but their work must be done [Lewis] |
| Full Idea: I suspend judgement about universals themselves; I only insist that, one way or another, their work must be done. | |
| From: David Lewis (New work for a theory of universals [1983], 'Intro') | |
| A reaction: This seems surprising (but admirable) in a great metaphysician, but I suppose it is symptomatic of the Humean approach to metaphysics. In the light of Ideas 3989 and 3990, I would have expected Lewis to deny universals. He probably did. |
| 21961 | Physics aims to discover which universals actually exist [Lewis, by Moore,AW] |
| Full Idea: For Lewis, we can see the purpose of physics as being to discover what universals there actually are. | |
| From: report of David Lewis (New work for a theory of universals [1983]) by A.W. Moore - The Evolution of Modern Metaphysics Intro | |
| A reaction: It seems that Lewis uses the word 'property' to mean predicates, which consist of a multitude of sets, while universals are the properties that naturally exist and cut nature at the joints . Infuriating, because the other way around seems better. |
| 8576 | The One over Many problem (in predication terms) deserves to be neglected (by ostriches) [Lewis] |
| Full Idea: The transformed problem of One over Many (in terms of predication, rather than sameness of type) deserves our neglect. The ostrich that will not look at it is a wise bird indeed. | |
| From: David Lewis (New work for a theory of universals [1983], '1 Ov Many') | |
| A reaction: This is aimed at Armstrong, and defends Quine. The remark moves Ostrich Nominalism from the category of joke to the category of respectable. I think I side with Armstrong. How is predication primitive if it has two components? |
| 8570 | To have a property is to be a member of a class, usually a class of things [Lewis] |
| Full Idea: To have a property is to be a member of a class, usually a class of things. (Note: this resembles the doctrine of Class Nominalism, but I do not claim to solve the One Over Many problem by this means, far from it). | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop') | |
| A reaction: Lewis remains neutral about the traditional question of whether universals exist. What does he mean by "is" in his assertion? Identity, predication or class membership? I think Lewis is open to many of the objections to Class Nominalism. |
| 8574 | Class Nominalism and Resemblance Nominalism are pretty much the same [Lewis] |
| Full Idea: Moderate Class Nominalism and Resemblance Nominalism (in its present form) seem to me to be a single theory presented in different styles. | |
| From: David Lewis (New work for a theory of universals [1983], 'Un and Prop' n9) | |
| A reaction: Lewis has earlier endorsed a cautious form of Class Nominalism (Idea 8570). Which comes first, having a resemblance, or being in a class? Quine seems to make resemblance basic (Idea 8486), but Lewis seems to make the class basic (Idea 8572). |
| 8579 | Psychophysical identity implies the possibility of idealism or panpsychism [Lewis] |
| Full Idea: Psychophysical identity is a two-way street: if all mental properties are physical, then some physical properties are mental; but then all physical properties might be mental, or every property of everything might be both physical and mental. | |
| From: David Lewis (New work for a theory of universals [1983], 'Min Mat') | |
| A reaction: I suspect that this is the thought that has impressed Galen Strawson. The whole story seems to include the existence of 'mental properties' as a distinct category. This line of thought strikes me as a serious misunderstanding. |
| 8614 | A sophisticated principle of charity sometimes imputes error as well as truth [Lewis] |
| Full Idea: Unlike principles of crude charity, sophisticated principles of charity call for imputations of error in the subject if he has lived in deceptive conditions. | |
| From: David Lewis (New work for a theory of universals [1983], 'Cont of L') | |
| A reaction: This begs lots of questions about how you decide conditions are 'deceptive' if you have not yet embarked on your radical interpretation of the subject. Davidson's point still stands, that imputing truth must be the normal procedure. |
| 8615 | We need natural properties in order to motivate the principle of charity [Lewis] |
| Full Idea: We need natural properties, so that the principle of charity will impute a bias towards believing that things are green rather than grue, and towards a basic desire for long life, rather than long-life-unless-one-was-born-on-a-Monday.... | |
| From: David Lewis (New work for a theory of universals [1983], 'Cont of L') | |
| A reaction: Lewis always seems to be approaching things from the wrong end. We don't need properties so that we can attribute charity, so that we can interpret. We interpret, because we can be charitable, because we all experience natural properties. |
| 8430 | Causal statements are used to explain, to predict, to control, to attribute responsibility, and in theories [Kim] |
| Full Idea: The function of causal statements is 1) to explain events, 2) for predictive usefulness, 3) to help control events, 4) with agents, to attribute moral responsibility, 5) in physical theory. We should judge causal theories by how they account for these. | |
| From: Jaegwon Kim (Causes and Counterfactuals [1973], p.207) | |
| A reaction: He suggests that Lewis's counterfactual theory won't do well on this test. I think the first one is what matters. Philosophy aims to understand, and that is achieved through explanation. Regularity and counterfactual theories explain very little. |
| 8396 | Many counterfactuals have nothing to do with causation [Kim, by Tooley] |
| Full Idea: Kim has pointed out that there are a number of counterfactuals that have nothing to do with causation. If John marries Mary, then if John had not existed he would not have married Mary, but that is not the cause of their union. | |
| From: report of Jaegwon Kim (Causes and Counterfactuals [1973], 5.2) by Michael Tooley - Causation and Supervenience | |
| A reaction: One might not think that this mattered, but it leaves the problem of distinguishing between the causal counterfactuals and the rest (and you mustn't mention causation when you are doing it!). |
| 8429 | Counterfactuals can express four other relations between events, apart from causation [Kim] |
| Full Idea: Counterfactuals can express 'analytical' dependency, or the fact that one event is part of another, or an action done by doing another, or (most interestingly) an event can determine another without causally determining it. | |
| From: Jaegwon Kim (Causes and Counterfactuals [1973], p.205) | |
| A reaction: [Kim gives example of each case] Counterfactuals can even express a relation that involves no dependency. Or they might just involve redescription, as in 'If Scott were still alive, then the author of "Waverley" would be too'. |
| 8428 | Causation is not the only dependency relation expressed by counterfactuals [Kim] |
| Full Idea: The sort of dependency expressed by counterfactual relations is considerably broader than strictly causal dependency, and causal dependency is only one among the heterogeneous group of dependency relationships counterfactuals can express. | |
| From: Jaegwon Kim (Causes and Counterfactuals [1973], p.205) | |
| A reaction: In 'If pigs could fly, one and one still wouldn't make three' there isn't even a dependency. Kim has opened up lines of criticism which make the counterfactual analysis of causation look very implausible to me. |
| 8608 | Counterfactuals 'backtrack' if a different present implies a different past [Lewis] |
| Full Idea: A counterfactual can be said to 'backtrack' if it can be said that if the present were different a different past would have led up to it (rather than if the present were different, the same past would have had a different outcome). | |
| From: David Lewis (New work for a theory of universals [1983], 'Dup,Sup,Div') | |
| A reaction: A nice clear definition of a concept which is important in Lewis's analysis of causation. In the current context he is concerned with elucidation of determinism and materialism. I would say (intuitively) that all counterfactuals backtrack. |
| 8584 | Causal counterfactuals must avoid backtracking, to avoid epiphenomena and preemption [Lewis] |
| Full Idea: My counterfactual analysis of causation needs counterfactuals that avoid backtracking; else the analysis faces fatal counterexamples involving epiphenomenal side-effects or cases of causal preemption. | |
| From: David Lewis (New work for a theory of universals [1983], 'Laws and C') | |
| A reaction: The concept of true epiphenomena (absolutely no causal powers) strikes me as bogus. |
| 8581 | Physics discovers laws and causal explanations, and also the natural properties required [Lewis] |
| Full Idea: Physics must not just discover laws and causal explanations. In putting forward as comprehensive theories that recognise only a limited range of natural properties, physics proposes inventories of the natural properties instantiated in our world. | |
| From: David Lewis (New work for a theory of universals [1983], 'Min Mat') | |
| A reaction: Physics does this job extremely well, offering things like force, spin, charge that are the building blocks for their theories. There is metaphysics at the heart of physics, unavoidably. |
| 15727 | Physics aims for a list of natural properties [Lewis] |
| Full Idea: Physics aspires to give an inventory of natural properties. | |
| From: David Lewis (New work for a theory of universals [1983], 'Dup,Sup,Div') | |
| A reaction: The sort of beautifully simple remark by which philosophers ought to earn a good living in the intellectual community. Come on physicists - this is all we want! Presumably the inventory will include an account of how they all work. |
| 8611 | A law of nature is any regularity that earns inclusion in the ideal system [Lewis] |
| Full Idea: A law of nature is any regularity that earns inclusion in the ideal system (or, in case of ties, in every ideal system). | |
| From: David Lewis (New work for a theory of universals [1983], 'Laws and C') | |
| A reaction: Reminiscent of Peirce's view of truth (Idea 7661). This wouldn't seem to eliminate the danger of regularities with underlying causes ending up as laws (day causes night). Or very trivial regularities ending up as laws. |
| 4781 | Many counterfactual truths do not imply causation ('if yesterday wasn't Monday, it isn't Tuesday') [Kim, by Psillos] |
| Full Idea: Kim gives a range of examples of counterfactual dependence without causation, as: 'if yesterday wasn't Monday, today wouldn't be Tuesday', and 'if my sister had not given birth, I would not be an uncle'. | |
| From: report of Jaegwon Kim (Causes and Counterfactuals [1973]) by Stathis Psillos - Causation and Explanation §3.3 | |
| A reaction: This is aimed at David Lewis. The objection seems like commonsense. "If you blink, the cat gets it". Causal claims involve counterfactuals, but they are not definitive of what causation is. |
| 21109 | Space itself can expand (and separate its contents) at faster than light speeds [Krauss] |
| Full Idea: Special Relativity says nothing can travel 'through space' faster than the speed of light. But space itself can do whatever the heck it wants, at least in general relativity. And it can carry distant objects apart from one another at superluminal speeds | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 06) | |
| A reaction: Another of my misunderstandings corrected. I assumed that the event horizon (limit of observability) was defined by the stuff retreating at (max) light speed. But beyond that it retreats even faster! What about the photons in space? |
| 21104 | General Relativity: the density of energy and matter determines curvature and gravity [Krauss] |
| Full Idea: The left-hand side of the general relativity equations descrbe the curvature of the universe, and the strength of gravitational forces acting on matter and radiation. The right-hand sides reflect the total density of all kinds of energy and matter. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 04) | |
| A reaction: I had assumed that the equations just described the geometry. In fact the matter determines the nature of the universe in which it exists. Presumably only things with mass get a vote. |
| 21107 | Uncertainty says that energy can be very high over very short time periods [Krauss] |
| Full Idea: The Heisenberg Uncertainty Principle says that the uncertainty in the measured energy of a system is inversely proportional to the length of time over which you observe it. (This allow near infinite energy over very short times). | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 04) | |
| A reaction: Apparently this brief energy is 'borrowed', and must be quickly repaid. |
| 21106 | Most of the mass of a proton is the energy in virtual particles (rather than the quarks) [Krauss] |
| Full Idea: The quarks provide very little of the total mass of a proton, and the fields created by the virtual particles contribute most of the energy that goes into the proton's rest energy and, hence, its mass. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 04) | |
| A reaction: He gives an artist's impression of the interior of a proton, which looks like a ship's engine room. |
| 21112 | Empty space contains a continual flux of brief virtual particles [Krauss] |
| Full Idea: Empty space is complicated. It is a boiling brew of virtual particles that pop in and out of existence in a time so short we cannot see them directly. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 10) | |
| A reaction: Apparently the interior of a proton is also like this. This fact gives a foot in the door for explanations of how the Big Bang got started, from these virtual particles. And yet surely space itself only arrives with the Big Bang? |
| 21108 | The universe is precisely 13.72 billion years old [Krauss] |
| Full Idea: We now know the age of the universe to four significant figures. It is 13.72 billion years old! | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 05) | |
| A reaction: It amazes me how many people, especially in philosophy, would be reluctant to accept that this is a know fact. I'm not accepting its certainty, but an assertion like this from a leading figure is good enough for me, and it should be for you. |
| 21111 | It seems likely that cosmic inflation is eternal, and this would make a multiverse inevitable [Krauss] |
| Full Idea: A multiverse is inevitable if inflation is eternal, and eternal inflation is by far the most likely possibility in most, if not all, inflationary scenarios. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 08) |