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All the ideas for 'A Structural Account of Mathematics', 'What is a Law of Nature?' and 'Rationale and Maxims in Study of Concepts'

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53 ideas

1. Philosophy / F. Analytic Philosophy / 7. Limitations of Analysis
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.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
Realists about sets say there exists a null set in the real world, with no members [Chihara]
     Full Idea: In the Gödelian realistic view of set theory the statement that there is a null set as the assertion of the existence in the real world of a set that has no members.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 11.6)
     A reaction: It seems to me obvious that such a claim is nonsense on stilts. 'In the beginning there was the null set'?
We only know relational facts about the empty set, but nothing intrinsic [Chihara]
     Full Idea: Everything we know about the empty set is relational; we know that nothing is the membership relation to it. But what do we know about its 'intrinsic properties'?
     From: Charles Chihara (A Structural Account of Mathematics [2004], 01.5)
     A reaction: Set theory seems to depend on the concept of the empty set. Modern theorists seem over-influenced by the Quine-Putnam view, that if science needs it, we must commit ourselves to its existence.
In simple type theory there is a hierarchy of null sets [Chihara]
     Full Idea: In simple type theory, there is a null set of type 1, a null set of type 2, a null set of type 3..... (Quine has expressed his distaste for this).
     From: Charles Chihara (A Structural Account of Mathematics [2004], 07.4)
     A reaction: It is bad enough trying to individuate the unique null set, without whole gangs of them drifting indistinguishably through the logical fog. All rational beings should share Quine's distaste, even if Quine is wrong.
The null set is a structural position which has no other position in membership relation [Chihara]
     Full Idea: In the structuralist view of sets, in structures of a certain sort the null set is taken to be a position (or point) that will be such that no other position (or point) will be in the membership relation to it.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 11.6)
     A reaction: It would be hard to conceive of something having a place in a structure if nothing had a relation to it, so is the null set related to singeton sets but not there members. It will be hard to avoid Platonism here. Set theory needs the null set.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
What is special about Bill Clinton's unit set, in comparison with all the others? [Chihara]
     Full Idea: What is it about the intrinsic properties of just that one unit set in virtue of which Bill Clinton is related to just it and not to any other unit sets in the set-theoretical universe?
     From: Charles Chihara (A Structural Account of Mathematics [2004], 01.5)
     A reaction: If we all kept pet woodlice, we had better not hold a wood louse rally, or we might go home with the wrong one. My singleton seems seems remarkably like yours. Could we, perhaps, swap, just for a change?
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
The set theorist cannot tell us what 'membership' is [Chihara]
     Full Idea: The set theorist cannot tell us anything about the true relationship of membership.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 01.5)
     A reaction: If three unrelated objects suddenly became members of a set, it is hard to see how the world would have changed, except in the minds of those thinking about it.
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
ZFU refers to the physical world, when it talks of 'urelements' [Chihara]
     Full Idea: ZFU set theory talks about physical objects (the urelements), and hence is in some way about the physical world.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 11.5)
     A reaction: This sounds a bit surprising, given that the whole theory would appear to be quite unaffected if God announced that idealism is true and there are no physical objects.
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
A pack of wolves doesn't cease when one member dies [Chihara]
     Full Idea: A pack of wolves is not thought to go out of existence just because some member of the pack is killed.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 07.5)
     A reaction: The point is that the formal extensional notion of a set doesn't correspond to our common sense notion of a group or class. Even a highly scientific theory about wolves needs a loose notion of a wolf pack.
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
The mathematics of relations is entirely covered by ordered pairs [Chihara]
     Full Idea: Everything one needs to do with relations in mathematics can be done by taking a relation to be a set of ordered pairs. (Ordered triples etc. can be defined as order pairs, so that <x,y,z> is <x,<y,z>>).
     From: Charles Chihara (A Structural Account of Mathematics [2004], 07.2)
     A reaction: How do we distinguish 'I own my cat' from 'I love my cat'? Or 'I quite like my cat' from 'I adore my cat'? Nevertheless, this is an interesting starting point for a discussion of relations.
5. Theory of Logic / K. Features of Logics / 2. Consistency
Sentences are consistent if they can all be true; for Frege it is that no contradiction can be deduced [Chihara]
     Full Idea: In first-order logic a set of sentences is 'consistent' iff there is an interpretation (or structure) in which the set of sentences is true. ..For Frege, though, a set of sentences is consistent if it is not possible to deduce a contradiction from it.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 02.1)
     A reaction: The first approach seems positive, the second negative. Frege seems to have a higher standard, which is appealing, but the first one seems intuitively right. There is a possible world where this could work.
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Analytic geometry gave space a mathematical structure, which could then have axioms [Chihara]
     Full Idea: With the invention of analytic geometry (by Fermat and then Descartes) physical space could be represented as having a mathematical structure, which could eventually lead to its axiomatization (by Hilbert).
     From: Charles Chihara (A Structural Account of Mathematics [2004], 02.3)
     A reaction: The idea that space might have axioms seems to be pythagoreanism run riot. I wonder if there is some flaw at the heart of Einstein's General Theory because of this?
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / c. Nominalist structuralism
We can replace existence of sets with possibility of constructing token sentences [Chihara, by MacBride]
     Full Idea: Chihara's 'constructability theory' is nominalist - mathematics is reducible to a simple theory of types. Instead of talk of sets {x:x is F}, we talk of open sentences Fx defining them. Existence claims become constructability of sentence tokens.
     From: report of Charles Chihara (A Structural Account of Mathematics [2004]) by Fraser MacBride - Review of Chihara's 'Structural Acc of Maths' p.81
     A reaction: This seems to be approaching the problem in a Fregean way, by giving an account of the semantics. Chihara is trying to evade the Quinean idea that assertion is ontological commitment. But has Chihara retreated too far? How does he assert existence?
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
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)
7. Existence / D. Theories of Reality / 11. Ontological Commitment / e. Ontological commitment problems
If a successful theory confirms mathematics, presumably a failed theory disconfirms it? [Chihara]
     Full Idea: If mathematics shares whatever confirmation accrues to the theories using it, would it not be reasonable to suppose that mathematics shares whatever disconfirmation accrues to the theories using it?
     From: Charles Chihara (A Structural Account of Mathematics [2004], 05.8)
     A reaction: Presumably Quine would bite the bullet here, although maths is much closer to the centre of his web of belief, and so far less likely to require adjustment. In practice, though, mathematics is not challenged whenever an experiment fails.
No scientific explanation would collapse if mathematical objects were shown not to exist [Chihara]
     Full Idea: Evidently, no scientific explanations of specific phenomena would collapse as a result of any hypothetical discovery that no mathematical objects exist.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 09.1)
     A reaction: It is inconceivable that anyone would challenge this claim. A good model seems to be drama; a play needs commitment from actors and audience, even when we know it is fiction. The point is that mathematics doesn't collapse either.
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
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)
8. Modes of Existence / B. Properties / 1. Nature of Properties
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.
8. Modes of Existence / B. Properties / 6. Categorical Properties
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.
8. Modes of Existence / C. Powers and Dispositions / 7. Against Powers
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?
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.
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.
8. Modes of Existence / D. Universals / 1. Universals
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.
8. Modes of Existence / D. Universals / 2. Need for Universals
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.
8. Modes of Existence / D. Universals / 3. Instantiated Universals
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.
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.
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?
9. Objects / A. Existence of Objects / 5. Individuation / b. Individuation by properties
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?
9. Objects / F. Identity among Objects / 5. Self-Identity
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.
10. Modality / B. Possibility / 5. Contingency
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.
14. Science / C. Induction / 3. Limits of Induction
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.
14. Science / C. Induction / 5. Paradoxes of Induction / a. Grue problem
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)
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.
14. Science / C. Induction / 5. Paradoxes of Induction / b. Raven paradox
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.
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
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.
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
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?).
14. Science / D. Explanation / 3. Best Explanation / a. Best explanation
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.
18. Thought / D. Concepts / 3. Ontology of Concepts / a. Concepts as representations
If concepts just are mental representations, what of concepts we may never acquire? [Peacocke]
     Full Idea: We might say that the concept just is the mental representation, ...but there are concepts that human beings may never acquire. ...But if concepts are individuated by their possession conditions this will not be a problem.
     From: Christopher Peacocke (Rationale and Maxims in Study of Concepts [2005], p.169), quoted by E Margolis/S Laurence - Concepts 1.3
     A reaction: I'm not sure that I understand the notion of a concept we (or any other creature) may never acquire. They no more seem to exist than buildings that were never even designed.
18. Thought / E. Abstraction / 1. Abstract Thought
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'.
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
I prefer the open sentences of a Constructibility Theory, to Platonist ideas of 'equivalence classes' [Chihara]
     Full Idea: What I refer to as an 'equivalence class' (of line segments of a particular length) is an open sentence in my Constructibility Theory. I just use this terminology of the Platonist for didactic purposes.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 09.10)
     A reaction: This is because 'equivalence classes' is committed to the existence of classes, which is Quinean Platonism. I am with Chihara in wanting a story that avoids such things. Kit Fine is investigating similar notions of rules of construction.
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
Mathematical entities are causally inert, so the causal theory of reference won't work for them [Chihara]
     Full Idea: Causal theories of reference seem doomed to failure for the case of reference to mathematical entities, since such entities are evidently causally inert.
     From: Charles Chihara (A Structural Account of Mathematics [2004], 01.3)
     A reaction: Presumably you could baptise a fictional entity such as 'Polonius', and initiate a social causal chain, with a tradition of reference. You could baptise a baby in absentia.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / e. The One
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.
26. Natural Theory / C. Causation / 2. Types of cause
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?
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
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?
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.
26. Natural Theory / D. Laws of Nature / 2. Types of Laws
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.
26. Natural Theory / D. Laws of Nature / 3. Laws and Generalities
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)
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
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'.
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.
26. Natural Theory / D. Laws of Nature / 5. Laws from Universals
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.
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.
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.
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
'Gunk' is an individual possessing no parts that are atoms [Chihara]
     Full Idea: An 'atomless gunk' is defined to be an individual possessing no parts that are atoms.
     From: Charles Chihara (A Structural Account of Mathematics [2004], App A)
     A reaction: [Lewis coined it] If you ask what are a-toms made of and what are ideas made of, the only answer we can offer is that the a-toms are made of gunk, and the ideas aren't made of anything, which is still bad news for the existence of ideas.