65 ideas
| 21959 | Metaphysics is the most general attempt to make sense of things [Moore,AW] |
| Full Idea: Metaphysics is the most general attempt to make sense of things. | |
| From: A.W. Moore (The Evolution of Modern Metaphysics [2012], Intro) | |
| A reaction: This is the first sentence of Moore's book, and a touchstone idea all the way through. It stands up well, because it says enough without committing to too much. I have to agree with it. It implies explanation as the key. I like generality too. |
| 17663 | If you know what it is, investigation is pointless. If you don't, investigation is impossible [Armstrong] |
| Full Idea: Paradox of Analysis:if we ask what sort of thing an X is, then either we know what an X is or we do not. If we know then there is no need to ask the question. If we do not know then there is no way to begin the investigation. It's pointless or impossible | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 01.2) | |
| A reaction: [G.E. Moore is the source of this, somewhere] Plato worried that to get to know something you must already know it. Solving this requires the concept of a 'benign' circularity. |
| 15413 | With four tense operators, all complex tenses reduce to fourteen basic cases [Burgess] |
| Full Idea: Fand P as 'will' and 'was', G as 'always going to be', H as 'always has been', all tenses reduce to 14 cases: the past series, each implying the next, FH,H,PH,HP,P,GP, and the future series PG,G,FG,GF,F,HF, plus GH=HG implying all, FP=PF which all imply. | |
| From: John P. Burgess (Philosophical Logic [2009], 2.8) | |
| A reaction: I have tried to translate the fourteen into English, but am not quite confident enough to publish them here. I leave it as an exercise for the reader. |
| 15415 | The temporal Barcan formulas fix what exists, which seems absurd [Burgess] |
| Full Idea: In temporal logic, if the converse Barcan formula holds then nothing goes out of existence, and the direct Barcan formula holds if nothing ever comes into existence. These results highlight the intuitive absurdity of the Barcan formulas. | |
| From: John P. Burgess (Philosophical Logic [2009], 2.9) | |
| A reaction: This is my reaction to the modal cases as well - the absurdity of thinking that no actually nonexistent thing might possibly have existed, or that the actual existents might not have existed. Williamson seems to be the biggest friend of the formulas. |
| 15430 | Is classical logic a part of intuitionist logic, or vice versa? [Burgess] |
| Full Idea: From one point of view intuitionistic logic is a part of classical logic, missing one axiom, from another classical logic is a part of intuitionistic logic, missing two connectives, intuitionistic v and → | |
| From: John P. Burgess (Philosophical Logic [2009], 6.4) |
| 15431 | It is still unsettled whether standard intuitionist logic is complete [Burgess] |
| Full Idea: The question of the completeness of the full intuitionistic logic for its intended interpretation is not yet fully resolved. | |
| From: John P. Burgess (Philosophical Logic [2009], 6.9) |
| 15429 | Relevance logic's → is perhaps expressible by 'if A, then B, for that reason' [Burgess] |
| Full Idea: The relevantist logician's → is perhaps expressible by 'if A, then B, for that reason'. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.8) |
| 15404 | Technical people see logic as any formal system that can be studied, not a study of argument validity [Burgess] |
| Full Idea: Among the more technically oriented a 'logic' no longer means a theory about which forms of argument are valid, but rather means any formalism, regardless of its applications, that resembles original logic enough to be studied by similar methods. | |
| From: John P. Burgess (Philosophical Logic [2009], Pref) | |
| A reaction: There doesn't seem to be any great intellectual obligation to be 'technical'. As far as pure logic is concerned, I am very drawn to the computer approach, since I take that to be the original dream of Aristotle and Leibniz - impersonal precision. |
| 15405 | Classical logic neglects the non-mathematical, such as temporality or modality [Burgess] |
| Full Idea: There are topics of great philosophical interest that classical logic neglects because they are not important to mathematics. …These include distinctions of past, present and future, or of necessary, actual and possible. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.1) |
| 15427 | The Cut Rule expresses the classical idea that entailment is transitive [Burgess] |
| Full Idea: The Cut rule (from A|-B and B|-C, infer A|-C) directly expresses the classical doctrine that entailment is transitive. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.3) |
| 15421 | Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess] |
| Full Idea: Classical logic neglects counterfactual conditionals for the same reason it neglects temporal and modal distinctions, namely, that they play no serious role in mathematics. | |
| From: John P. Burgess (Philosophical Logic [2009], 4.1) | |
| A reaction: Science obviously needs counterfactuals, and metaphysics needs modality. Maybe so-called 'classical' logic will be renamed 'basic mathematical logic'. Philosophy will become a lot clearer when that happens. |
| 15403 | Philosophical logic is a branch of logic, and is now centred in computer science [Burgess] |
| Full Idea: Philosophical logic is a branch of logic, a technical subject. …Its centre of gravity today lies in theoretical computer science. | |
| From: John P. Burgess (Philosophical Logic [2009], Pref) | |
| A reaction: He firmly distinguishes it from 'philosophy of logic', but doesn't spell it out. I take it that philosophical logic concerns metaprinciples which compare logical systems, and suggest new lines of research. Philosophy of logic seems more like metaphysics. |
| 15407 | Formalising arguments favours lots of connectives; proving things favours having very few [Burgess] |
| Full Idea: When formalising arguments it is convenient to have as many connectives as possible available.; but when proving results about formulas it is convenient to have as few as possible. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.4) | |
| A reaction: Illuminating. The fact that you can whittle classical logic down to two (or even fewer!) connectives warms the heart of technicians, but makes connection to real life much more difficult. Hence a bunch of extras get added. |
| 15424 | Asserting a disjunction from one disjunct seems odd, but can be sensible, and needed in maths [Burgess] |
| Full Idea: Gricean implicature theory might suggest that a disjunction is never assertable when a disjunct is (though actually the disjunction might be 'pertinent') - but the procedure is indispensable in mathematical practice. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.2) | |
| A reaction: He gives an example of a proof in maths which needs it, and an unusual conversational occasion where it makes sense. |
| 15409 | All occurrences of variables in atomic formulas are free [Burgess] |
| Full Idea: All occurrences of variables in atomic formulas are free. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.7) |
| 15414 | The denotation of a definite description is flexible, rather than rigid [Burgess] |
| Full Idea: By contrast to rigidly designating proper names, …the denotation of definite descriptions is (in general) not rigid but flexible. | |
| From: John P. Burgess (Philosophical Logic [2009], 2.9) | |
| A reaction: This modern way of putting it greatly clarifies why Russell was interested in the type of reference involved in definite descriptions. Obviously some descriptions (such as 'the only person who could ever have…') might be rigid. |
| 15406 | 'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess] |
| Full Idea: There are atomic formulas, and formulas built from the connectives, and that is all. We show that all formulas have some property, first for the atomics, then the others. This proof is 'induction on complexity'; we also use 'recursion on complexity'. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.4) | |
| A reaction: That is: 'induction on complexity' builds a proof from atomics, via connectives; 'recursion on complexity' breaks down to the atomics, also via the connectives. You prove something by showing it is rooted in simple truths. |
| 15425 | The sequent calculus makes it possible to have proof without transitivity of entailment [Burgess] |
| Full Idea: It might be wondered how one could have any kind of proof procedure at all if transitivity of entailment is disallowed, but the sequent calculus can get around the difficulty. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.3) | |
| A reaction: He gives examples where transitivity of entailment (so that you can build endless chains of deductions) might fail. This is the point of the 'cut free' version of sequent calculus, since the cut rule allows transitivity. |
| 15426 | We can build one expanding sequence, instead of a chain of deductions [Burgess] |
| Full Idea: Instead of demonstrations which are either axioms, or follow from axioms by rules, we can have one ever-growing sequence of formulas of the form 'Axioms |- ______', where the blank is filled by Axioms, then Lemmas, then Theorems, then Corollaries. | |
| From: John P. Burgess (Philosophical Logic [2009], 5.3) |
| 15408 | 'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics [Burgess] |
| Full Idea: The valid formulas of classical sentential logic are called 'tautologically valid', or simply 'tautologies'; with other logics 'tautologies' are formulas that are substitution instances of valid formulas of classical sentential logic. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.5) |
| 15418 | Validity (for truth) and demonstrability (for proof) have correlates in satisfiability and consistency [Burgess] |
| Full Idea: Validity (truth by virtue of logical form alone) and demonstrability (provability by virtue of logical form alone) have correlative notions of logical possibility, 'satisfiability' and 'consistency', which come apart in some logics. | |
| From: John P. Burgess (Philosophical Logic [2009], 3.3) |
| 15412 | Models leave out meaning, and just focus on truth values [Burgess] |
| Full Idea: Models generally deliberately leave out meaning, retaining only what is important for the determination of truth values. | |
| From: John P. Burgess (Philosophical Logic [2009], 2.2) | |
| A reaction: This is the key point to hang on to, if you are to avoid confusing mathematical models with models of things in the real world. |
| 15411 | We only need to study mathematical models, since all other models are isomorphic to these [Burgess] |
| Full Idea: In practice there is no need to consider any but mathematical models, models whose universes consist of mathematical objects, since every model is isomorphic to one of these. | |
| From: John P. Burgess (Philosophical Logic [2009], 1.8) | |
| A reaction: The crucial link is the technique of Gödel Numbering, which can translate any verbal formula into numerical form. He adds that, because of the Löwenheim-Skolem theorem only subsets of the natural numbers need be considered. |
| 15416 | We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess] |
| Full Idea: The aim in setting up a model theory is that the technical notion of truth in all models should agree with the intuitive notion of truth in all instances. A model is supposed to represent everything about an instance that matters for its truth. | |
| From: John P. Burgess (Philosophical Logic [2009], 3.2) |
| 15428 | The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess] |
| Full Idea: It is a common view that the liar sentence ('This very sentence is not true') is an instance of a truth-value gap (neither true nor false), but some dialethists cite it as an example of a truth-value glut (both true and false). | |
| From: John P. Burgess (Philosophical Logic [2009], 5.7) | |
| A reaction: The defence of the glut view must be that it is true, then it is false, then it is true... Could it manage both at once? |
| 17688 | Negative facts are supervenient on positive facts, suggesting they are positive facts [Armstrong] |
| Full Idea: Negative facts appear to be supervenient upon the positive facts, which suggests that they are nothing more than the positive facts. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 10.3) |
| 17691 | Nothing is genuinely related to itself [Armstrong] |
| Full Idea: I believe that nothing is genuinely related to itself. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 10.7) |
| 17679 | All instances of some property are strictly identical [Armstrong] |
| Full Idea: A property ...is something which is strictly identical, strictly the same, in all its different instances. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.2) | |
| A reaction: Some is gravitation one property, or an infinity of properties, for each of its values? What is the same between objects of different mass. I sort of believe in all the masses, but I'm not sure what 'mass' is. Abstraction, say I. |
| 12677 | Armstrong holds that all basic properties are categorical [Armstrong, by Ellis] |
| Full Idea: I am against Armstrong's strong categoricalism, that is, the thesis that all basic properties are categorical. | |
| From: report of David M. Armstrong (What is a Law of Nature? [1983]) by Brian Ellis - The Metaphysics of Scientific Realism 3 | |
| A reaction: I certainly agree with this, as I cannot see where the power would come from to get the whole thing off the ground. Armstrong depends on universals to necessitate what happens, which I find very peculiar. |
| 17666 | Actualism means that ontology cannot contain what is merely physically possible [Armstrong] |
| Full Idea: Actualism ...debars us from admitting into our ontology the merely possible, not only the merely logically possible, but also the merely physically possible. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 01.3) | |
| A reaction: This is the big metaphysical question for fans (like myself) of 'powers' in nature. Armstrong declares himself an Actualist. I take it as obvious that the actual world contains powers, but how are we to characterise them? |
| 17667 | Dispositions exist, but their truth-makers are actual or categorical properties [Armstrong] |
| Full Idea: It is not denied that statements attributing dispositions and/or powers to objects are often true. But the truth-makers or ontological ground for such statements must always be found in the actual, or categorical, properties of the objects involved. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 01.3) | |
| A reaction: This is the big debate in the topic of powers. I love powers, but you always think there must be 'something' which has the power. Could reality entirely consist of powers? See Fetzer. |
| 17687 | If everything is powers there is a vicious regress, as powers are defined by more powers [Armstrong] |
| Full Idea: I believe reducing all universals to powers is involved in vicious regress. The power is what it is by the sort of actualisations it gives rise to in suitable sorts of circumstances. But they themselves can be nothing but powers... | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 08.3) | |
| A reaction: [compressed wording] I don't see this problem. Anything postulated as fundamental is going to be baffling. Why are categorical properties superior to powers? Postulate basic powers (or basic empowered stuff), then build up. |
| 17678 | Universals are just the repeatable features of a world [Armstrong] |
| Full Idea: Universals can be brought into the spatio-temporal world, becoming simply the repeatable features of that world. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.2) | |
| A reaction: I wish Armstrong wouldn't use the word 'universal', which has so much historical baggage. The world obviously has repeatable features, but does that mean that our ontology must include things called 'features'? Hm. |
| 17669 | Realist regularity theories of laws need universals, to pick out the same phenomena [Armstrong] |
| Full Idea: A Realistic version of a Regularity theory of laws will have to postulate universals. How else will it be possible to say that the different instances of a certain uniformity are all instances of objectively the same phenomenon? | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 02.4) | |
| A reaction: I disagree. We may (or may not) need properties, but they can be have a range. We just need stable language. We use one word 'red', even when the shade of redness varies. Non-realists presumably refer to sense-data. |
| 17677 | Past, present and future must be equally real if universals are instantiated [Armstrong] |
| Full Idea: Past, present and future I take to be all and equally real. A universal need not be instantiated now. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.2) | |
| A reaction: This is the price you must pay for saying that you only believe in universals which are instantiated. |
| 15442 | Universals are abstractions from their particular instances [Armstrong, by Lewis] |
| Full Idea: Armstrong takes universals generally, and structural universals along with the rest, to be abstractions from their particular instances. | |
| From: report of David M. Armstrong (What is a Law of Nature? [1983], p.83-4) by David Lewis - Against Structural Universals 'The pictorial' | |
| A reaction: To me, 'abstracted' implies a process of human psychology, a way of thinking about the instances. I don't see how there can be an 'abstracted' relation which is a part of the external world. That makes his laws of nature human creations. |
| 17686 | Universals are abstractions from states of affairs [Armstrong] |
| Full Idea: Universals are abstractions from states of affairs. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 7) | |
| A reaction: I'm getting confused about Armstrong's commitments. He bases his whole theory on the existence of universals (repeatable features), but now says those are 'abstracted' from something else. Abstracted by us? |
| 17668 | It is likely that particulars can be individuated by unique conjunctions of properties [Armstrong] |
| Full Idea: For each particular it is likely that there exists at least one individuating conjunction of properties, that is, a conjunction of properties such that the particular instantiates this conjunction and nothing else does. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 02.3) | |
| A reaction: Armstrong commits to a famous Leibniz view, but I don't see his grounds for it. There is nothing incoherent about nature churning out perfect replicas of things, such as quarks and electrons. Would we care if two pens were perfectly identical? |
| 17680 | The identity of a thing with itself can be ruled out as a pseudo-property [Armstrong] |
| Full Idea: There is reason to rule out as pseudo-properties such things as the identity of a thing with itself. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.2) | |
| A reaction: Good on you, David. |
| 15420 | De re modality seems to apply to objects a concept intended for sentences [Burgess] |
| Full Idea: There is a problem over 'de re' modality (as contrasted with 'de dicto'), as in ∃x□x. What is meant by '"it is analytic that Px" is satisfied by a', given that analyticity is a notion that in the first instance applies to complete sentences? | |
| From: John P. Burgess (Philosophical Logic [2009], 3.9) | |
| A reaction: This is Burgess's summary of one of Quine's original objections. The issue may be a distinction between whether the sentence is analytic, and what makes it analytic. The necessity of bachelors being unmarried makes that sentence analytic. |
| 15419 | General consensus is S5 for logical modality of validity, and S4 for proof [Burgess] |
| Full Idea: To the extent that there is any conventional wisdom about the question, it is that S5 is correct for alethic logical modality, and S4 correct for apodictic logical modality. | |
| From: John P. Burgess (Philosophical Logic [2009], 3.8) | |
| A reaction: In classical logic these coincide, so presumably one should use the minimum system to do the job, which is S4 (?). |
| 15417 | Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess] |
| Full Idea: Logical necessity is a genus with two species. For classical logic the truth-related notion of validity and the proof-related notion of demonstrability, coincide - but they are distinct concept. In some logics they come apart, in intension and extension. | |
| From: John P. Burgess (Philosophical Logic [2009], 3.3) | |
| A reaction: They coincide in classical logic because it is sound and complete. This strikes me as the correct approach to logical necessity, tying it to the actual nature of logic, rather than some handwavy notion of just 'true in all possible worlds'. |
| 17693 | The necessary/contingent distinction may need to recognise possibilities as real [Armstrong] |
| Full Idea: It may be that the necessary/contingent distinction is tied to a metaphysics which recognises possibility as a real something wider than actuality. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 11.2) | |
| A reaction: Armstrong responds by trying to give an account of possibility in terms of 'combinations' from actuality. I think powers offer a much better strategy. |
| 15422 | Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess] |
| Full Idea: Three main theories of the truth of indicative conditionals are Materialism (the conditions are the same as for the material conditional), Idealism (identifying assertability with truth-value), and Nihilism (no truth, just assertability). | |
| From: John P. Burgess (Philosophical Logic [2009], 4.3) |
| 15423 | It is doubtful whether the negation of a conditional has any clear meaning [Burgess] |
| Full Idea: It is contentious whether conditionals have negations, and whether 'it is not the case that if A,B' has any clear meaning. | |
| From: John P. Burgess (Philosophical Logic [2009], 4.9) | |
| A reaction: This seems to be connected to Lewis's proof that a probability conditional cannot be reduced to a single proposition. If a conditional only applies to A-worlds, it is not surprising that its meaning gets lost when it leaves that world. |
| 21958 | Appearances are nothing beyond representations, which is transcendental ideality [Moore,AW] |
| Full Idea: Appearances in general are nothing outside our representations, which is just what we mean by transcendental ideality. | |
| From: A.W. Moore (The Evolution of Modern Metaphysics [2012], B535/A507) |
| 17685 | Induction aims at 'all Fs', but abduction aims at hidden or theoretical entities [Armstrong] |
| Full Idea: Many philosophers of science have distinguished between 'simple induction' - the argument from observed Fs to all Fs - and the argument to hidden or theoretical entities (Peirce's 'abduction'). | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.7) | |
| A reaction: 'Abduction' is (roughly) the same is inference to the best explanation, of which I am a great fan. |
| 17683 | Science suggests that the predicate 'grue' is not a genuine single universal [Armstrong] |
| Full Idea: It is plausible to say, on the basis of total science, that 'grue' is a predicate to which no genuine, that is, unitary, universal corresponds. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.7) |
| 17675 | Unlike 'green', the 'grue' predicate involves a time and a change [Armstrong] |
| Full Idea: The predicate 'grue' involves essential reference to a particular time, which 'green' does not. Also on the 'grue' hypothesis a change occurs in emeralds in a way that change does not occur on the 'green' hypothesis. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 04.5) | |
| A reaction: I'm inclined to think that comparing 'grue' with 'green' is a category mistake. 'Grue' is a behaviour. Armstrong says this is no objection, because Goodman's argument is purely formal. |
| 17674 | The raven paradox has three disjuncts, confirmed by confirming any one of them [Armstrong] |
| Full Idea: We could rewrite the generalisation as For all x, ((x is a raven and x is black) v (x is not a raven and x is black) v (x is not a raven and x is not black)). Instances of any one of the three disjuncts will do as confirmation. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 04.3) | |
| A reaction: A nice clarification. |
| 17672 | A good reason for something (the smoke) is not an explanation of it (the fire) [Armstrong] |
| Full Idea: A good reason for P is not necessarily an explanation of P. The presence of smoke is a good reason for thinking that fire is present. But it is not an explanation of the presence of fire. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 04.2) | |
| A reaction: This may be an equivocation on 'the reason for'. Smoke is a reason for thinking there is a fire, but no one would propose it as a reason for the fire. If the reason for the fire was arson, that would seem to explain it as well. |
| 17684 | To explain observations by a regular law is to explain the observations by the observations [Armstrong] |
| Full Idea: Given the Regularity theory, the explanatory element seems to vanish. For to say that all the observed Fs are Gs because all the Fs are Gs involves explaining the observations in terms of themselves. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.7) | |
| A reaction: This point cries out, it is so obvious (once spotted). Tigers are ferocious because all tigers are ferocious (see?). |
| 17676 | Best explanations explain the most by means of the least [Armstrong] |
| Full Idea: The best explanation explains the most by means of the least. Explanation unifies. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 05.4) | |
| A reaction: To get unification, you need to cite the diversity of what is explained, and not the mere quantity. The force of gravity unifies because it applies to such a diversity of things. |
| 17664 | Each subject has an appropriate level of abstraction [Armstrong] |
| Full Idea: To every subject, its appropriate level of abstraction. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 01.2) | |
| A reaction: Mathematics rises through many levels of abstraction. Economics can be very concrete or very abstract. It think it is clearer to talk of being 'general', rather than 'abstract'. |
| 17692 | We can't deduce the phenomena from the One [Armstrong] |
| Full Idea: No serious and principled deduction of the phenomena from the One has ever been given, or looks likely to be given. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 11) | |
| A reaction: This seems to pick out the best reason why hardly anybody (apart from Jonathan Schaffer) takes the One seriously. |
| 17689 | Absences might be effects, but surely not causes? [Armstrong] |
| Full Idea: Lacks and absences could perhaps by thought of as effects, but we ought to be deeply reluctant to think of them as causes. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 10.4) | |
| A reaction: Odd. So we allow that they exist (as effects), but then deny that they have any causal powers? |
| 17682 | A universe couldn't consist of mere laws [Armstrong] |
| Full Idea: A universe could hardly consist of laws and nothing else. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.4) | |
| A reaction: Hm. Discuss. How does a universe come into existence, if there are no laws to guide its creation? |
| 17662 | Science depends on laws of nature to study unobserved times and spaces [Armstrong] |
| Full Idea: The scientist trying to establish the geography and history of the unobserved portion of the universe must depend upon what he takes to be the laws of the universe. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 01.1) | |
| A reaction: This does seem to be the prime reason why we wish to invoke 'laws', but we could just as well say that we have to rely on induction. Spot patterns, then expect more of the same. Spot necessities? Mathematics is very valuable here, of course. |
| 17690 | Oaken conditional laws, Iron universal laws, and Steel necessary laws [Armstrong, by PG] |
| Full Idea: Three degress of law: 1) 'Oaken laws' where all Fs that aren't Hs are Gs; 2) 'Iron' laws where all Fs are Gs; and 3) 'Steel' laws where all Fs must be Gs. | |
| From: report of David M. Armstrong (What is a Law of Nature? [1983], 10.4) by PG - Db (ideas) | |
| A reaction: [My summary of Armstrong's distinction] One response is to say that all laws are actually Oaken - see Mumfor and Mumford/Lill Anjum. It's all ceteris paribus. |
| 17670 | Newton's First Law refers to bodies not acted upon by a force, but there may be no such body [Armstrong] |
| Full Idea: Newton's First Law of Motion tells us what happens to a body which is not acted upon by a force. Yet it may be that the antecedent of the law is never instantiated. It may be that every body that there is, is acted upon by some force. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 02.7) |
| 8582 | Regularities are lawful if a second-order universal unites two first-order universals [Armstrong, by Lewis] |
| Full Idea: Armstrong's theory holds that what makes certain regularities lawful are second-order states of affairs N(F,G) in which the two ordinary first-order universals F and G are related by a certain dyadic second-order universal N. | |
| From: report of David M. Armstrong (What is a Law of Nature? [1983]) by David Lewis - New work for a theory of universals 'Laws and C' | |
| A reaction: [see Lewis's footnote] I take the view (from Shoemaker and Ellis) that laws of nature are just plain regularities which arise from the hierarchy of natural kinds. We don't need a commitment to 'universals'. |
| 17671 | A naive regularity view says if it never occurs then it is impossible [Armstrong] |
| Full Idea: It is a Humean uniformity that no race of ravens is white-feathered. Hence, if the Naive Regularity analysis of law is correct, it is a law that no race of ravens is white-feathered, that is, such a race is physically impossible. A most unwelcome result. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 02.6) | |
| A reaction: Chapters 2-4 of Armstrong are a storming attack on the regularity view of laws of nature, and this idea is particularly nice. Laws must refer to what could happen, not what happens to happen. |
| 17681 | The laws of nature link properties with properties [Armstrong] |
| Full Idea: There is an utterly natural idea that the laws of nature link properties with properties. | |
| From: David M. Armstrong (What is a Law of Nature? [1983], 06.3) | |
| A reaction: Put it this way: given that properties are expressions of invariant powers, the interaction of two properties will (ceteris paribus) be invariant, and laws are just invariances in natural behaviour. |
| 16246 | Rather than take necessitation between universals as primitive, just make laws primitive [Maudlin on Armstrong] |
| Full Idea: My own view is simple: the laws of nature ought to be accepted as ontologically primitive. …They are preferable in point of familiarity to such necessitation relations between universals. | |
| From: comment on David M. Armstrong (What is a Law of Nature? [1983]) by Tim Maudlin - The Metaphysics within Physics 1.4 | |
| A reaction: I think you make natures of things primitive, and reduce laws to regularities and universals to resemblances. Job done. Natures are even more 'familiar' as primitives than laws are. |
| 9480 | Armstrong has an unclear notion of contingent necessitation, which can't necessitate anything [Bird on Armstrong] |
| Full Idea: The two criticisms levelled against Armstrong are that it is unclear what his relation of contingent necessitation is, and that it is unclear how it is able to necessitate anything. | |
| From: comment on David M. Armstrong (What is a Law of Nature? [1983]) by Alexander Bird - Nature's Metaphysics 3.1.2 | |
| A reaction: I suppose someone has to explore the middle ground between the mere contingencies of Humean regularities and the strong necessities of scientific essentialism. The area doesn't, however, look promising. |