55 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). |
| 22270 | Frege changed philosophy by extending logic's ability to check the grounds of thinking [Potter on Frege] |
| Full Idea: Frege's 1879 logic transformed philosophy because it greatly expanded logic's reach - what thought can achieve unaided - and hence compelled a re-examination of everything previously said about the grounds of thought when logic gives out. | |
| From: comment on Gottlob Frege (Begriffsschrift [1879]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 Intro | |
| A reaction: I loved the gloss on logic as 'what thought can achieve unaided'. I largely see logic in terms of what is mechanically computable. |
| 8939 | We should not describe human laws of thought, but how to correctly track truth [Frege, by Fisher] |
| Full Idea: Frege disagree that logic should merely describe the laws of thought - how people actually did reason. Logic is essentially normative, not descriptive. We want the one logic which successfully tracks the truth. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Jennifer Fisher - On the Philosophy of Logic 1.III | |
| A reaction: This explains Frege's sustained attack on psychologism, and it also explains we he ended up as a platonist about logic - because he wanted its laws to be valid independently of human thinking. A step too far, perhaps. Brains are truth machines. |
| 4971 | I don't use 'subject' and 'predicate' in my way of representing a judgement [Frege] |
| Full Idea: A distinction of subject and predicate finds no place in my way of representing a judgement. | |
| From: Gottlob Frege (Begriffsschrift [1879], §03) | |
| A reaction: Perhaps this sentence could be taken as the beginning of modern analytical philosophy. The old view doesn't seem to me entirely redundant - merely replaced by a much more detailed analysis of what makes a 'subject' and what makes a 'predicate'. |
| 17745 | For Frege, 'All A's are B's' means that the concept A implies the concept B [Frege, by Walicki] |
| Full Idea: 'All A's are B's' meant for Frege that the concept A implies the concept B, or that to be A implies also to be B. Moreover this applies to arbitrary x which happens to be A. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Michal Walicki - Introduction to Mathematical Logic History D.2 | |
| A reaction: This seems to hit the renate/cordate problem. If all creatures with hearts also have kidneys, does that mean that being enhearted logically implies being kidneyfied? If all chimps are hairy, is that a logical requirement? Is inclusion implication? |
| 7728 | Frege has a judgement stroke (vertical, asserting or judging) and a content stroke (horizontal, expressing) [Frege, by Weiner] |
| Full Idea: Frege distinguished between asserting a proposition and expressing it, and he introduced the judgement stroke (a small vertical line, assertion) and the content stroke (a long horizontal line, expression) to represent them. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Joan Weiner - Frege Ch.3 | |
| A reaction: There are also strokes for conditional and denial. |
| 16881 | The laws of logic are boundless, so we want the few whose power contains the others [Frege] |
| Full Idea: Since in view of the boundless multitude of laws that can be enunciated we cannot list them all, we cannot achieve completeness except by searching out those that, by their power, contain all of them. | |
| From: Gottlob Frege (Begriffsschrift [1879], §13) | |
| A reaction: He refers to these laws in the previous sentence as the 'core'. His talk of 'power' is music to my ears, since it implies a direction of explanation. Burge says the power is that of defining other concepts. |
| 7622 | In 1879 Frege developed second order logic [Frege, by Putnam] |
| Full Idea: By 1879 Frege had discovered an algorithm, a mechanical proof procedure, that embraces what is today standard 'second order logic'. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Hilary Putnam - Reason, Truth and History Ch.5 | |
| A reaction: Note that Frege did more than introduce quantifiers, and the logic of predicates. |
| 7729 | Frege replaced Aristotle's subject/predicate form with function/argument form [Frege, by Weiner] |
| Full Idea: Frege's regimentation is based on the view of the simplest sort of statement as having, not subject/predicate form (as in Aristotle), but function/argument form. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Joan Weiner - Frege | |
| A reaction: This looks like being a crucial move into the modern world, where one piece of information is taken in and dealt with, as in computer procedures. Have educated people reorganised their minds along Fregean lines? |
| 9950 | A quantifier is a second-level predicate (which explains how it contributes to truth-conditions) [Frege, by George/Velleman] |
| Full Idea: The contribution of the quantifier to the truth conditions of sentences of which it is a part cannot be adequately explained if it is treated as other than a second-level predicate (for instance, if it is viewed as name). | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.2 | |
| A reaction: They suggest that this makes it something like a 'property of properties'. With this account it becomes plausible to think of numbers as quantifiers (since they do, after all, specify quantities). |
| 9991 | For Frege the variable ranges over all objects [Frege, by Tait] |
| Full Idea: For Frege the variable ranges over all objects. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by William W. Tait - Frege versus Cantor and Dedekind XII | |
| A reaction: The point is that Frege had not yet seen the necessity to define the domain of quantification, and this leads him into various difficulties. |
| 10536 | Frege's domain for variables is all objects, but modern interpretations first fix the domain [Dummett on Frege] |
| Full Idea: For Frege there is no need to specify the domain of the individual variables, which is taken as the totality of all objects. This contrasts with the standard notion of an interpretation, which demands that we first fix the domain. | |
| From: comment on Gottlob Frege (Begriffsschrift [1879]) by Michael Dummett - Frege Philosophy of Language (2nd ed) Ch.14 | |
| A reaction: What intrigues me is how domains of quantification shift according to context in ordinary usage, even in mid-sentence. I ought to go through every idea in this database, specifying its domain of quantification. Any volunteers? |
| 7742 | Frege reduced most quantifiers to 'everything' combined with 'not' [Frege, by McCullogh] |
| Full Idea: Frege treated 'everything' as basic, and suggested ways of recasting propositions containing other quantifiers so that this was the only one remaining. He recast 'something' as 'at least one thing', and defined this in terms of 'everything' and 'not'. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Gregory McCullogh - The Game of the Name 1.6 | |
| A reaction: Extreme parsimony seems highly desirable in logic as well as ontology, but it can lead to frustrations, especially over the crucial question of the existence of things quantified over. See Idea 6068. |
| 7730 | Frege introduced quantifiers for generality [Frege, by Weiner] |
| Full Idea: In order to express generality, Frege introduced quantifier notation. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Joan Weiner - Frege | |
| A reaction: This is the birth of predicate logic, beloved of analytical philosophers (but of no apparent interest to phenomenalists, deconstructionists, existentialists?). Generality is what you get from induction (which is, of course, problematic). |
| 13824 | Proof theory began with Frege's definition of derivability [Frege, by Prawitz] |
| Full Idea: Frege's formal definition of derivability is perhaps the first investigation in general proof theory. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Dag Prawitz - Gentzen's Analysis of First-Order Proofs 2 n2 | |
| A reaction: In 'On General Proof Theory §1' Prawitz says "proof theory originated with Hilbert" in 1900. Presumably Frege offered a theory, and then Hilbert saw it as a general project. |
| 13609 | Frege produced axioms for logic, though that does not now seem the natural basis for logic [Frege, by Kaplan] |
| Full Idea: Frege's work supplied a set of axioms for logic itself, at least partly because it was a well-known way of presenting the foundations in other disciplines, especially mathematics, but it does not nowadays strike us as natural for logic. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by David Kaplan - Dthat 5.1 | |
| A reaction: What Bostock has in mind is the so-called 'natural' deduction systems, which base logic on rules of entailment, rather than on a set of truths. The axiomatic approach uses a set of truths, plus the idea of possible contradictions. |
| 17855 | It may be possible to define induction in terms of the ancestral relation [Frege, by Wright,C] |
| Full Idea: Frege's account of the ancestral has made it possible, in effect, to define the natural numbers as entities for which induction holds. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Crispin Wright - Frege's Concept of Numbers as Objects 4.xix | |
| A reaction: This is the opposite of the approach in the Peano Axioms, where induction is used to define the natural numbers. |
| 10607 | Frege's logic has a hierarchy of object, property, property-of-property etc. [Frege, by Smith,P] |
| Full Idea: Frege's general logical system involves a type hierarchy, distinguishing objects from properties from properties-of-properties etc., with every item belonging to a determinate level. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Peter Smith - Intro to Gödel's Theorems 14.1 | |
| A reaction: The Theory of Types went on to apply this hierarchy to classes, where Frege's disastrous Basic Law V flattens the hierarchy of classes, putting them on the same level (Smith p.119) |
| 11008 | Existence is not a first-order property, but the instantiation of a property [Frege, by Read] |
| Full Idea: When Kant said that existence was not a property, what he meant was, according to Frege, that existence is not a first-order property - it is not a property of individuals but a property of properties, that the property has an instance. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Stephen Read - Thinking About Logic Ch.5 |
| 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. |
| 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. |
| 22280 | Frege's account was top-down and decompositional, not bottom-up and compositional [Frege, by Potter] |
| Full Idea: Frege's account was top-down, not bottom-up: he aimed to decompose and discern function-argument structure in already existing sentences, not to explain how those sentences acquired their meanings in the first place. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 03 'Func' | |
| A reaction: This goes with the holistic account of meaning, which leads to Quine's gavagai and Kuhn's obfuscation of science. I recommend compositionality for everthing. |
| 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. |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| Full Idea: Archelaus was the first person to say that the universe is boundless. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
| 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. |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
| Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
| A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |
| 7741 | The predicate 'exists' is actually a natural language expression for a quantifier [Frege, by Weiner] |
| Full Idea: On Frege's logical analysis, the predicate 'exists' is actually a natural language expression for a quantifier. | |
| From: report of Gottlob Frege (Begriffsschrift [1879]) by Joan Weiner - Frege Ch.8 | |
| A reaction: However see Idea 6067, for McGinn's alternative view of quantifiers. In the normal conventions of predicate logic it may be that existence is treated as a quantifier, but that is not the same as saying that existence just IS a quantifier. |