Combining Texts

All the ideas for 'Thinking About Mathematics', 'Letter to Shumacher' and 'Powers'

unexpand these ideas     |    start again     |     specify just one area for these texts


54 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Substantive metaphysics says what a property is, not what a predicate means [Molnar]
     Full Idea: The motto of what is presented here is 'less conceptual analysis, more metaphysics', where the distinction is equivalent to the distinction between saying what 'F' means and saying what being F is.
     From: George Molnar (Powers [1998], 1.1)
     A reaction: This seems to me to capture exactly the spirit of metaphysics since Saul Kripke's work, though some people engaged in it seem to me to be trapped in an outdated linguistic view of the matter. Molnar credits Locke as the source of his view.
2. Reason / D. Definition / 4. Real Definition
A real definition gives all the properties that constitute an identity [Molnar]
     Full Idea: A real definition expresses the sum of the properties that constitute the identity of the thing defined.
     From: George Molnar (Powers [1998], 1.4.4)
     A reaction: This is a standard modern view among modern essentialists, and one which I believe can come into question. It seems to miss out the fact that an essence will also explain the possible functions and behaviours of a thing. Explanation seems basic.
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro]
     Full Idea: Intuitionists in mathematics deny excluded middle, because it is symptomatic of faith in the transcendent existence of mathematical objects and/or the truth of mathematical statements.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2)
     A reaction: There are other problems with excluded middle, such as vagueness, but on the whole I, as a card-carrying 'realist', am committed to the law of excluded middle.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro]
     Full Idea: It is surely wise to identify the positions in the natural numbers structure with their counterparts in the integer, rational, real and complex number structures.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2)
     A reaction: The point is that this might be denied, since 3, 3/1, 3.00.., and -3*i^2 are all arrived at by different methods of construction. Natural 3 has a predecessor, but real 3 doesn't. I agree, intuitively, with Shapiro. Russell (1919) disagreed.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
Cauchy gave a formal definition of a converging sequence. [Shapiro]
     Full Idea: A sequence a1,a2,... of rational numbers is 'Cauchy' if for each rational number ε>0 there is a natural number N such that for all natural numbers m, n, if m>N and n>N then -ε < am - an < ε.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 7.2 n4)
     A reaction: The sequence is 'Cauchy' if N exists.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
Actual infinities are not allowed in mathematics - only limits which may increase without bound [Gauss]
     Full Idea: I protest against the use of an infinite quantity as an actual entity; this is never allowed in mathematics. The infinite is only a manner of speaking, in which one properly speaks of limits ...which are permitted to increase without bound.
     From: Carl Friedrich Gauss (Letter to Shumacher [1831]), quoted by Brian Clegg - Infinity: Quest to Think the Unthinkable Ch.7
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
Categories are the best foundation for mathematics [Shapiro]
     Full Idea: There is a dedicated contingent who hold that the category of 'categories' is the proper foundation for mathematics.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.3 n7)
     A reaction: He cites Lawvere (1966) and McLarty (1993), the latter presenting the view as a form of structuralism. I would say that the concept of a category will need further explication, and probably reduce to either sets or relations or properties.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro]
     Full Idea: Zermelo said that for each number n, its successor is the singleton of n, so 3 is {{{null}}}, and 1 is not a member of 3. Von Neumann said each number n is the set of numbers less than n, so 3 is {null,{null},{null,{null}}}, and 1 is a member of 3.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.2)
     A reaction: See Idea 645 - Zermelo could save Plato from the criticisms of Aristotle! These two accounts are cited by opponents of the set-theoretical account of numbers, because it seems impossible to arbitrate between them.
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro]
     Full Idea: The structuralist vigorously rejects any sort of ontological independence among the natural numbers; the essence of a natural number is its relations to other natural numbers.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1)
     A reaction: This seems to place the emphasis on ordinals (what order?) rather than on cardinality (how many?). I am strongly inclined to think that this is the correct view, though you can't really have relations if there is nothing to relate.
A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro]
     Full Idea: A 'system' is a collection of objects with certain relations among them; a 'pattern' or 'structure' is the abstract form of a system, highlighting the interrelationships and ignoring any features they do not affect how they relate to other objects.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 10.1)
     A reaction: Note that 'ignoring' features is a psychological account of abstraction, which (thanks to Frege and Geach) is supposed to be taboo - but which I suspect is actually indispensable in any proper account of thought and concepts.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro]
     Full Idea: The thesis that principles of arithmetic are derivable from the laws of logic runs against a now common view that logic itself has no ontology. There are no particular logical objects. From this perspective logicism is a non-starter.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 5.1)
     A reaction: This criticism strikes me as utterly devastating. There are two routes to go: prove that logic does have an ontology of objects (what would they be?), or - better - deny that arithmetic contains any 'objects'. Or give up logicism.
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro]
     Full Idea: Term Formalism is the view that mathematics is just about characters or symbols - the systems of numerals and other linguistic forms. ...This will cover integers and rational numbers, but what are real numbers supposed to be, if they lack names?
     From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.1)
     A reaction: Real numbers (such as pi and root-2) have infinite decimal expansions, so we can start naming those. We could also start giving names like 'Harry' to other reals, though it might take a while. OK, I give up.
Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro]
     Full Idea: Game Formalism likens mathematics to chess, where the 'content' of mathematics is exhausted by the rules of operating with its language. ...This, however, leaves the problem of why the mathematical games are so useful to the sciences.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 6.1.2)
     A reaction: This thought pushes us towards structuralism. It could still be a game, but one we learned from observing nature, which plays its own games. Chess is, after all, modelled on warfare.
Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro]
     Full Idea: The Deductivist version of formalism (sometimes called 'if-thenism') says that the practice of mathematics consists of determining logical consequences of otherwise uninterpreted axioms.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 6.2)
     A reaction: [Hilbert is the source] More plausible than Term or Game Formalism (qv). It still leaves the question of why it seems applicable to nature, and why those particular axioms might be chosen. In some sense, though, it is obviously right.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro]
     Full Idea: Critics commonly complain that the intuitionist restrictions cripple the mathematician. On the other hand, intuitionist mathematics allows for many potentially important distinctions not available in classical mathematics, and is often more subtle.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 7.1)
     A reaction: The main way in which it cripples is its restriction on talk of infinity ('Cantor's heaven'), which was resented by Hilbert. Since high-level infinities are interesting, it would be odd if we were not allowed to discuss them.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro]
     Full Idea: I classify conceptualists according to what they say about properties or concepts. If someone classified properties as existing independent of language I would classify her as a realist in ontology of mathematics. Or they may be idealists or nominalists.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 2.2.1)
     A reaction: In other words, Shapiro wants to eliminate 'conceptualist' as a useful label in philosophy of mathematics. He's probably right. All thought involves concepts, but that doesn't produce a conceptualist theory of, say, football.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
'Impredicative' definitions refer to the thing being described [Shapiro]
     Full Idea: A definition of a mathematical entity is 'impredicative' if it refers to a collection that contains the defined entity. The definition of 'least upper bound' is impredicative as it refers to upper bounds and characterizes a member of this set.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 1.2)
     A reaction: The big question is whether mathematics can live with impredicative definitions, or whether they threaten to be viciously circular, and undermine the whole enterprise.
7. Existence / C. Structure of Existence / 4. Ontological Dependence
Ontological dependence rests on essential connection, not necessary connection [Molnar]
     Full Idea: Ontological dependence is better understood in terms of an essential connection, rather than simply a necessary connection.
     From: George Molnar (Powers [1998], 1.4.4)
     A reaction: This seems to be an important piece in the essentialist jigsaw. Apart from essentialism, I can't think of any doctrine which offers any sort of explanation of the self-evident fact of certain ontological dependencies.
7. Existence / E. Categories / 3. Proposed Categories
The three categories in ontology are objects, properties and relations [Molnar]
     Full Idea: The ontologically fundamental categories are three in number: Objects, Properties, and Relations.
     From: George Molnar (Powers [1998], 2 Intr)
     A reaction: We need second-order logic to quantify over all of these. The challenge to this view might be that it is static, and needs the addition of processes or events. Molnar rejects facts and states of affairs.
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
Reflexive relations are syntactically polyadic but ontologically monadic [Molnar]
     Full Idea: Reflexive relations are, and non-reflexive relations may be, monadic in the ontological sense although they are syntactically polyadic.
     From: George Molnar (Powers [1998], 1.4.5)
     A reaction: I find this a very helpful distinction, as I have never quite understood reflexive relations as 'relations', even in the most obvious cases, such as self-love or self-slaughter.
8. Modes of Existence / B. Properties / 1. Nature of Properties
If atomism is true, then all properties derive from ultimate properties [Molnar]
     Full Idea: If a priori atomism is a true theory of the world, then all properties are derivative from ultimate properties.
     From: George Molnar (Powers [1998], 1.4.1)
     A reaction: Presumably there is a physicalist metaphysic underlying this, which means that even abstract properties derive ultimately from these physical atoms. Unless we want to postulate logical atoms, or monads, or some such weird thing.
8. Modes of Existence / B. Properties / 5. Natural Properties
'Being physical' is a second-order property [Molnar]
     Full Idea: A property like 'being physical' is just a second-order property. ...It is not required as a first-order property. ...Higher-order properties earn their keep as necessity-makers.
     From: George Molnar (Powers [1998], 1.4.2)
     A reaction: I take this to be correct and very important. People who like 'abundant' properties don't make this distinction about orders (of levels of abstraction, I would say), so the whole hierarchy has an equal status in ontology, which is ridiculous.
8. Modes of Existence / B. Properties / 6. Categorical Properties
'Categorical properties' are those which are not powers [Molnar]
     Full Idea: The canonical name for a property that is a non-power is 'categorical property'.
     From: George Molnar (Powers [1998], 10.2)
     A reaction: Molnar objects that this implies that powers cannot be used categorically, and refuses to use the term. There seems to be uncertainty over whether the term refers to necessity, or to the ability to categorise. I'm getting confused myself.
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
Are tropes transferable? If they are, that is a version of Platonism [Molnar]
     Full Idea: Are tropes transferable? ...If tropes are not dependent on their bearers, that is a trope-theoretic version of Platonism.
     From: George Molnar (Powers [1998], 1.4.6)
     A reaction: These are the sort of beautifully simple questions that we pay philosophers to come up with. If they are transferable, what was the loose bond which connected them? If they aren't, then what individuates them?
8. Modes of Existence / C. Powers and Dispositions / 1. Powers
A power's type-identity is given by its definitive manifestation [Molnar]
     Full Idea: A power's type-identity is given by its definitive manifestation.
     From: George Molnar (Powers [1998], 3.1)
     A reaction: Presumably there remains an I-know-not-what that lurks behind the manifestation, which is beyond our limits of cognizance. The ultimate reality of the world has to be unknowable.
Powers have Directedness, Independence, Actuality, Intrinsicality and Objectivity [Molnar]
     Full Idea: The basic features of powers are: Directedness (to some outcome); Independence (from their manifestations); Actuality (not mere possibilities); Intrinsicality (not relying on other objects) and Objectivity (rather than psychological).
     From: George Molnar (Powers [1998], 2.4)
     A reaction: [compression of his list] This offering is why Molnar's book is important, because no one else seems to get to grips with trying to pin down what a power is, and hence their role.
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
The physical world has a feature very like mental intentionality [Molnar]
     Full Idea: Something very much like mental intentionality is a pervasive and ineliminable feature of the physical world.
     From: George Molnar (Powers [1998], 3.2)
     A reaction: I like this, because it offers a continuous account of mind and world. The idea that intentionality is some magic ingredient that marks off a non-physical type of reality is nonsense. See Fodor's attempts to reduce intentionality.
Dispositions and external powers arise entirely from intrinsic powers in objects [Molnar]
     Full Idea: I propose a generalization: that all dispositional and extrinsic predicates that apply to an object, do so by virtue of intrinsic powers borne by the object.
     From: George Molnar (Powers [1998], 6.3)
     A reaction: This is the clearest statement of the 'powers' view of nature, and the one with which I agree. An interesting question is whether powers or objects are more basic in our ontology. Are objects just collections of causal powers? What has the power?
The Standard Model suggest that particles are entirely dispositional, and hence are powers [Molnar]
     Full Idea: In the Standard Model of physics the fundamental physical magnitudes are represented as ones whose whole nature is exhausted by the dispositionality, ..so there is a strong presumption that the properties of subatomic particles are powers.
     From: George Molnar (Powers [1998], 8.4.3)
     A reaction: A very nice point, because it asserts not merely that we should revise our metaphysic to endorse powers, but that we are actually already operating with exactly that view, in so far as we are physicalist.
Some powers are ungrounded, and others rest on them, and are derivative [Molnar]
     Full Idea: Some powers are grounded and some are not. ...All derivative powers ultimately derive from ungrounded powers.
     From: George Molnar (Powers [1998], 8.5.2)
     A reaction: It is tempting to use the term 'property' for the derivative powers, reserving 'power' for something which is basic. Molnar makes a plausible case, though.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
Dispositions can be causes, so they must be part of the actual world [Molnar]
     Full Idea: Dispositions can be causes. What is not actual cannot be a cause or any part of a cause. Merely possible events are not actual, and that makes them causally impotent. The claim that powers are causally potent has strong initial plausibility.
     From: George Molnar (Powers [1998], 5)
     A reaction: [He credits Mellor 1974 for this idea] He will need to show how dispositions can be causes (other than, presumably, being anticipated or imagined by conscious minds), which he says he will do in Ch. 12.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / b. Dispositions and powers
If powers only exist when actual, they seem to be nomadic, and indistinguishable from non-powers [Molnar]
     Full Idea: Two arguments against Megaran Actualism are that it turns powers into nomads: they come and go, depending on whether they are being exercised or not. And it stops us from distinguishing between unexercised powers and absent powers.
     From: George Molnar (Powers [1998], 4.3.1)
     A reaction: See Idea 11938 for Megaran Actualism. Molnar takes these objections to be fairly decisive, but if the Megarans are denying the existence of latent powers, they aren't going to be bothered by nomadism or the lack of distinction.
8. Modes of Existence / D. Universals / 6. Platonic Forms / d. Forms critiques
Platonic explanations of universals actually diminish our understanding [Molnar]
     Full Idea: We understand less after a platonic explanation of universals than we understand before it was given.
     From: George Molnar (Powers [1998], 1.2)
     A reaction: That pretty much sums up my view, and it pretty well sums up my view of religion as well. I thought I understood what numbers were until Frege told me that they were abstract objects, some sort of higher-order set.
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
For nominalists, predicate extensions are inexplicable facts [Molnar]
     Full Idea: For the nominalist, belonging to the extension of a predicate is just an inexplicable ultimate fact.
     From: George Molnar (Powers [1998], 1.2)
     A reaction: I sometimes think of myself as a nominalist, but when it is summarised in Molnar's way I back off. He seem to be offering a third way, between platonic realism and nominalism. It is physical essentialist realism, I think.
Nominalists only accept first-order logic [Molnar]
     Full Idea: A nominalist will only countenance first-order logic.
     From: George Molnar (Powers [1998], 12.2.2)
     A reaction: This is because nominalist will not acknowledge properties as entities to be quantified over. Plural quantification seems to be a strategy for extending first-order logic while retaining nominalist sympathies.
9. Objects / C. Structure of Objects / 1. Structure of an Object
There are no 'structural properties', as properties with parts [Molnar]
     Full Idea: There are no 'structural properties', if by that we mean a property that has properties as parts.
     From: George Molnar (Powers [1998], 9.1.2)
     A reaction: There do seem to be properties that result from arranging more basic properties in one way rather than another (e.g. arranging the metal in a knife to be 'sharp'). But I think Molnar is right that they are not part of basic ontology.
Structural properties are derivate properties [Molnar]
     Full Idea: Structural properties are clear examples of derivative properties.
     From: George Molnar (Powers [1998], 1.4.3)
     A reaction: This is an important question in the debate. Presumably you can't just reduce structural properties to more basic ones, because one set of basic properties might appear in many different structures. Ellis defends structural properties in metaphysics.
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
The essence of a thing need not include everything that is necessarily true of it [Molnar]
     Full Idea: Pre-theoretically it does not seem to be the case that what is essential to a thing includes everything that is necessarily true of that thing.
     From: George Molnar (Powers [1998], 1.4.4)
     A reaction: This seems to me to be true. The simple point, which I take to be obvious, is that essential properties must at the very least be in some way important, whereas necessities can be trivial. I favour the idea that the essences create the necessities.
10. Modality / B. Possibility / 1. Possibility
What is the truthmaker for a non-existent possible? [Molnar]
     Full Idea: What is the nature of the truthmaker for 'It is possible that p' in cases where p itself is false?
     From: George Molnar (Powers [1998], 12.2.2)
     A reaction: Molnar mentions three views: there is a different type of being for possibilia (Meinong), or possibilia exist, or possibilia are merely represented. The third view is obviously correct, though I presume possibilia to be based on actual powers.
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]
     Full Idea: Rationalism is a long-standing school that can be characterized as an attempt to extend the perceived methodology of mathematics to all of knowledge.
     From: Stewart Shapiro (Thinking About Mathematics [2000], 1.1)
     A reaction: Sometimes called 'Descartes's Dream', or the 'Enlightenment Project', the dream of proving everything. Within maths, Hilbert's Programme aimed for the same certainty. Idea 22 is the motto for the opposition to this approach.
14. Science / D. Explanation / 1. Explanation / a. Explanation
Hume allows interpolation, even though it and extrapolation are not actually valid [Molnar]
     Full Idea: In his 'shade of blue' example, Hume is (sensibly) endorsing a type of reasoning - interpolation - that is widely used by rational thinkers. Too bad that interpolation and extrapolation are incurably invalid.
     From: George Molnar (Powers [1998], 7.2.3)
     A reaction: Interpolation and extrapolation are two aspects of inductive reasoning which contribute to our notion of best explanation. Empiricism has to allow at least some knowledge which goes beyond strict direct experience.
15. Nature of Minds / A. Nature of Mind / 1. Mind / a. Mind
The two ways proposed to distinguish mind are intentionality or consciousness [Molnar]
     Full Idea: There have only been two serious proposals for distinguishing mind from matter. One appeals to intentionality, as per Brentano and his medieval precursors. The other, harking back to Descartes, Locke and empiricism, uses the capacity for consciousness.
     From: George Molnar (Powers [1998], 3.5.3)
     A reaction: Personally I take both of these to be reducible, and hence have no place for 'minds' in my ontology. Focusing on Chalmers's 'Hard Question' was the shift from the intentionality view to the consciousness view which is now more popular.
15. Nature of Minds / B. Features of Minds / 4. Intentionality / a. Nature of intentionality
Physical powers like solubility and charge also have directedness [Molnar]
     Full Idea: Contrary to the Brentano Thesis, physical powers, such as solubility or electromagnetic charge, also have that direction toward something outside themselves that is typical of psychological attributes.
     From: George Molnar (Powers [1998], 3.4)
     A reaction: I think this decisively undermines any strong thesis that 'intentionality is the mark of the mental'. I take thought to be just a fancy development of the physical powers of the physical world.
17. Mind and Body / A. Mind-Body Dualism / 4. Occasionalism
Rule occasionalism says God's actions follow laws, not miracles [Molnar]
     Full Idea: Rule occasionalists (Arnauld, Bayle) say that on their view the results of God's action are the nomic regularities of nature, and not a miracle.
     From: George Molnar (Powers [1998], 6.1)
     A reaction: This is clearly more plausible that Malebranche's idea that God constantly intervenes. I take it as a nice illustration of the fact that 'laws of nature' were mainly invented by us to explain how God could control his world. Away with them!
26. Natural Theory / C. Causation / 2. Types of cause
Singular causation is prior to general causation; each aspirin produces the aspirin generalization [Molnar]
     Full Idea: I take for granted the primacy of singular causation. A singular causal state of affairs is not constituted by a generalization. 'Aspirin relieves headache' is made true by 'This/that aspirin relieves this/that headache'.
     From: George Molnar (Powers [1998], 12.1)
     A reaction: [He cites Tooley for the opposite view] I wholly agree with Molnar, and am inclined to link it with the primacy of individual essences over kind essences.
26. Natural Theory / C. Causation / 4. Naturalised causation
We should analyse causation in terms of powers, not vice versa [Molnar]
     Full Idea: Causal analyses of powers pre-empt the correct account of causation in terms of powers.
     From: George Molnar (Powers [1998], 4.2.3)
     A reaction: I think this is my preferred view. The crucial point is that powers are active, so one is not needing to add some weird 'causation' ingredient to a world which would otherwise be passive and inert. That is a relic from the interventions of God.
26. Natural Theory / C. Causation / 7. Eliminating causation
We should analyse causation in terms of powers [Molnar]
     Full Idea: We should give up any causal analysis of powers, ..so we should try to analyse causation in terms of powers.
     From: George Molnar (Powers [1998], 8.5.3)
     A reaction: It may be hard to explain what powers are, or identify them, if you can't say that they cause things to happen. I am torn between Molnar's view, and the view that causation is primitive.
26. Natural Theory / C. Causation / 9. General Causation / c. Counterfactual causation
Causal dependence explains counterfactual dependence, not vice versa [Molnar]
     Full Idea: The counterfactual analysis is open to the Euthyphro objection: it is causal dependence that explains any counterfactual dependence rather than vice versa.
     From: George Molnar (Powers [1998], 12.1)
     A reaction: I take views like the counterfactual analysis of causation to arise from empiricists who are bizarrely reluctant to adopt plausible best explainations (such as powers and essences).
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
Science works when we assume natural kinds have essences - because it is true [Molnar]
     Full Idea: Investigations premissed on the assumption that natural kinds have essences, that in particular the fundamental natural kinds have only essential intrinsic properties, tend to be practically successful because the assumption is true.
     From: George Molnar (Powers [1998], 11.3)
     A reaction: The point is made against a pragmatist approach to the problem by Nancy Cartwright. I take the starting point for scientific essentialism to be an empirical observation, that natural kinds seem to be very very stable. See Idea 8153.
Location in space and time are non-power properties [Molnar, by Mumford]
     Full Idea: Molnar argues that some properties are non-powers, and he cites spatial location, spatial orientation, and temporal location.
     From: report of George Molnar (Powers [1998], 158-62) by Stephen Mumford - Laws in Nature 11.4
     A reaction: Although you might say an event happened 'because' of an item on this list, this doesn't feel right to me. The ability to arrest someone is a power, but being at the scene of the crime isn't. It's an opportunity for a power.
One essential property of a muon doesn't entail the others [Molnar]
     Full Idea: The muon has mass 106.2 MeV, unit negative charge, and spin a half. The electron and tauon have unit negative charge, but electrons are 200 times less massive, and tauons 17 times more massive. Its essential properties are not mutually entailing.
     From: George Molnar (Powers [1998], 2.1)
     A reaction: This rejects a popular idea of scientific essentialism, that the essence is the set of properties which entail the non-essential properties (and not vice versa), a view which I had hitherto found rather appealing.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / b. Scientific necessity
It is contingent which kinds and powers exist in the world [Molnar]
     Full Idea: It is a contingent matter that the world contains the exact natural kinds it does, and hence it is a contingent matter that it contains the very powers it does.
     From: George Molnar (Powers [1998], 10.3)
     A reaction: I take this to be correct (for all we know). It would be daft to claim that the regularities of the universe are necessarily that way, but it is not daft to say that the stuff of the universe necessitates the pattern of what happens.
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
The laws of nature depend on the powers, not the other way round [Molnar]
     Full Idea: What powers there are does not depend on what laws there are, but vice versa, what laws obtain in the world is a function of what powers are to be found in that world.
     From: George Molnar (Powers [1998], 1.4.5)
     A reaction: This old idea may well be the most important realisation of modern times. I take the 'law' view to be based on a religious view of the world (see Idea 5470). There is still room to believe in a divine creator of the bewildering underlying powers.
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / b. Fields
Energy fields are discontinuous at the very small [Molnar]
     Full Idea: We know that all energy fields are discontinuous below the distance measured by Planck's constant h. The physical world ultimately consists of discrete objects.
     From: George Molnar (Powers [1998], 2.2)
     A reaction: This is where quantum theory clashes with relativity, since the latter holds space to be a continuum. I'm not sure about Molnar's use of the word 'objects' here.