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All the ideas for 'Frege philosophy of mathematics', 'How to Russell a Frege-Church' and 'Powers'

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69 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the spirit of metaphysics since Saul Kripke's work, though some people engaged in it seem to me to be trapped in an outdated linguistic view of the matter.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.
2. Reason / D. Definition / 7. Contextual Definition
A contextual definition permits the elimination of the expression by a substitution [Dummett]
     Full Idea: The standard sense of a 'contextual definition' permits the eliminating of the defined expression, by transforming any sentence containing it into an equivalent one not containing it.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.11)
     A reaction: So the whole definition might be eliminated by a single word, which is not equivalent to the target word, which is embedded in the original expression. Clearly contextual definitions have some problems
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
In classical logic, logical truths are valid formulas; in higher-order logics they are purely logical [Dummett]
     Full Idea: For sentential or first-order logic, the logical truths are represented by valid formulas; in higher-order logics, by sentences formulated in purely logical terms.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 3)
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / c. Theory of definite descriptions
For Russell, expressions dependent on contingent circumstances must be eliminated [Kaplan]
     Full Idea: It is a tenet of Russell's theory that all expressions, and especially definite descriptions, whose denotation is dependent upon contingent circumstances must be eliminated.
     From: David Kaplan (How to Russell a Frege-Church [1975], II)
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
A prime number is one which is measured by a unit alone [Dummett]
     Full Idea: A prime number is one which is measured by a unit alone.
     From: Michael Dummett (Frege philosophy of mathematics [1991], 7 Def 11)
     A reaction: We might say that the only way of 'reaching' or 'constructing' a prime is by incrementing by one till you reach it. That seems a pretty good definition. 64, for example, can be reached by a large number of different routes.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / c. Priority of numbers
Addition of quantities is prior to ordering, as shown in cyclic domains like angles [Dummett]
     Full Idea: It is essential to a quantitative domain of any kind that there should be an operation of adding its elements; that this is more fundamental thaat that they should be linearly ordered by magnitude is apparent from cyclic domains like that of angles.
     From: Michael Dummett (Frege philosophy of mathematics [1991], 22 'Quantit')
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units
A number is a multitude composed of units [Dummett]
     Full Idea: A number is a multitude composed of units.
     From: Michael Dummett (Frege philosophy of mathematics [1991], 7 Def 2)
     A reaction: This is outdated by the assumption that 0 and 1 are also numbers, but if we say one is really just the 'unit' which is preliminary to numbers, and 0 is as bogus a number as i is, we might stick with the original Greek distinction.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / e. Counting by correlation
We understand 'there are as many nuts as apples' as easily by pairing them as by counting them [Dummett]
     Full Idea: A child understands 'there are just as many nuts as apples' as easily by pairing them off as by counting them.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.12)
     A reaction: I find it very intriguing that you could know that two sets have the same number, without knowing any numbers. Is it like knowing two foreigners spoke the same words, without understanding them? Or is 'equinumerous' conceptually prior to 'number'?
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
The identity of a number may be fixed by something outside structure - by counting [Dummett]
     Full Idea: The identity of a mathematical object may sometimes be fixed by its relation to what lies outside the structure to which it belongs. It is more fundamental to '3' that if certain objects are counted, there are three of them.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 5)
     A reaction: This strikes me as Dummett being pushed (by his dislike of the purely abstract picture given by structuralism) back to a rather empiricist and physical view of numbers, though he would totally deny that.
Numbers aren't fixed by position in a structure; it won't tell you whether to start with 0 or 1 [Dummett]
     Full Idea: The number 0 is not differentiated from 1 by its position in a progression, otherwise there would be no difference between starting with 0 and starting with 1. That is enough to show that numbers are not identifiable just as positions in structures.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 5)
     A reaction: This sounds conclusive, but doesn't feel right. If numbers are a structure, then where you 'start' seems unimportant. Where do you 'start' in St Paul's Cathedral? Starting sounds like a constructivist concept for number theory.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Set theory isn't part of logic, and why reduce to something more complex? [Dummett]
     Full Idea: The two frequent modern objects to logicism are that set theory is not part of logic, or that it is of no interest to 'reduce' a mathematical theory to another, more complex, one.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.18)
     A reaction: Dummett says these are irrelevant (see context). The first one seems a good objection. The second one less so, because whether something is 'complex' is a quite different issue from whether it is ontologically more fundamental.
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 / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
The distinction of concrete/abstract, or actual/non-actual, is a scale, not a dichotomy [Dummett]
     Full Idea: The distinction between concrete and abstract objects, or Frege's corresponding distinction between actual and non-actual objects, is not a sharp dichotomy, but resembles a scale upon which objects occupy a range of positions.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.18)
     A reaction: This might seem right if you live (as Dummett chooses to) in the fog of language, but it surely can't be right if you think about reality. Is the Equator supposed to be near the middle of his scale? Either there is an equator, or there isn't.
7. Existence / D. Theories of Reality / 2. Realism
Realism is just the application of two-valued semantics to sentences [Dummett]
     Full Idea: Fully fledged realism depends on - indeed, may be identified with - an undiluted application to sentences of the relevant kind of straightforwards two-valued semantics.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.15)
     A reaction: This is the sort of account you get from a whole-heartedly linguistic philosopher. Personally I would say that Dummett has got it precisely the wrong way round: I adopt a two-valued semantics because my metaphysics is realist.
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
Nominalism assumes unmediated mental contact with objects [Dummett]
     Full Idea: The nominalist superstition is based ultimately on the myth of the unmediated presentation of genuine concrete objects to the mind.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.18)
     A reaction: Personally I am inclined to favour nominalism and a representative theory of perception, which acknowledges some 'mediation', but of a non-linguistic form. Any good theory here had better include animals, which seem to form concepts.
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 / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
The existence of abstract objects is a pseudo-problem [Dummett]
     Full Idea: The existence of abstract objects is a pseudo-problem.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.18)
     A reaction: This remark follows after Idea 9884, which says the abstract/concrete distinction is a sliding scale. Personally I take the distinction to be fairly sharp, and it is therefore probably the single most important problem in the whole of human thought.
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
Abstract objects nowadays are those which are objective but not actual [Dummett]
     Full Idea: Objects which are objective but not actual are precisely what are now called abstract objects.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.15)
     A reaction: Why can there not be subjective abstract objects? 'My favourites are x, y and z'. 'I'll decide later what my favourites are'. 'I only buy my favourites - nothing else'.
It is absurd to deny the Equator, on the grounds that it lacks causal powers [Dummett]
     Full Idea: If someone argued that assuming the existence of the Equator explains nothing, and it has no causal powers, so everything would be the same if it didn't exist, so we needn't accept its existence, we should gape at the crudity of the misunderstanding.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.15)
     A reaction: Not me. I would gape if someone argued that latitude 55° 14' (and an infinity of other lines) exists for the same reasons (whatever they may be) that the Equator exists. A mode of description can't create an object.
'We've crossed the Equator' has truth-conditions, so accept the Equator - and it's an object [Dummett]
     Full Idea: 'We've crossed the Equator' is judged true if we are nearer the other Pole, so it not for philosophers to deny that the Earth has an equator, and we see that the Equator is not a concept or relation or function, so it must be classified as an object.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.15)
     A reaction: A lovely example of linguistic philosophy in action (and so much the worse for that, I would say). A useful label here, I suggest (unoriginally, I think), is that we should label such an item a 'semantic object', rather than a real object in our ontology.
9. Objects / A. Existence of Objects / 2. Abstract Objects / d. Problems with abstracta
Abstract objects need the context principle, since they can't be encountered directly [Dummett]
     Full Idea: To recognise that there is no objection in principle to abstract objects requires acknowledgement that some form of the context principle is correct, since abstract objects can neither be encountered nor presented.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.16)
     A reaction: I take this to be an immensely important idea. I consider myself to be a philosopher of thought rather than a philosopher of language (Dummett's distinction, he being one of the latter). Thought connects to the world, but does it connect to abstracta?
9. Objects / C. Structure of Objects / 1. Structure of an Object
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.
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.
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.
9. Objects / F. Identity among Objects / 2. Defining Identity
Content is replaceable if identical, so replaceability can't define identity [Dummett, by Dummett]
     Full Idea: Husserl says the only ground for assuming the replaceability of one content by another is their identity; we are therefore not entitled to define their identity as consisting in their replaceability.
     From: report of Michael Dummett (Frege philosophy of mathematics [1991]) by Michael Dummett - Frege philosophy of mathematics Ch.12
     A reaction: This is a direct challenge to Frege. Tricky to arbitrate, as it is an issue of conceptual priority. My intuition is with Husserl, but maybe the two are just benignly inerdefinable.
Frege introduced criteria for identity, but thought defining identity was circular [Dummett]
     Full Idea: In his middle period Frege rated identity indefinable, on the ground that every definition must take the form of an identity-statement. Frege introduced the notion of criterion of identity, which has been widely used by analytical philosophers.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.10)
     A reaction: The objection that attempts to define identity would be circular sounds quite plausible. It sounds right to seek a criterion for type-identity (in shared properties or predicates), but token-identity looks too fundamental to give clear criteria.
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.
10. Modality / E. Possible worlds / 3. Transworld Objects / d. Haecceitism
'Haecceitism' says that sameness or difference of individuals is independent of appearances [Kaplan]
     Full Idea: The doctrine that we can ask whether this is the same individual in another possible world, and that a common 'thisness' may underlie extreme dissimilarity, or distinct thisnesses may underlie great resemblance, I call 'Haecceitism'.
     From: David Kaplan (How to Russell a Frege-Church [1975], IV)
     A reaction: Penelope Mackie emphasises that this doctrine, that each thing is somehow individuated, is not the same as believing in actual haecceities, specific properties which achieve the individuating.
'Haecceitism' is common thisness under dissimilarity, or distinct thisnesses under resemblance [Kaplan]
     Full Idea: That a common 'thisness' may underlie extreme dissimilarity or distinct thisnesses may underlie great resemblance I call 'haecceitism'. (I prefer the pronunciation Hex'-ee-i-tis-m).
     From: David Kaplan (How to Russell a Frege-Church [1975], IV)
     A reaction: [odd pronunciation, if 'haec' is pronounced haeek] The view seems to be very unpopular (e.g. with Lewis, Bird and Mumford). But there is an intuitive sense of whether or not two things are identical when they seem dissimilar.
If quantification into modal contexts is legitimate, that seems to imply some form of haecceitism [Kaplan]
     Full Idea: If one regards the usual form of quantification into modal and other intensional contexts - modality de re - as legitimate (without special explanations), then one seems committed to some form of haecceitism.
     From: David Kaplan (How to Russell a Frege-Church [1975], IV)
     A reaction: That is, modal reference requires fixed identities, irrespective of possible changes in properties. Why could one not refer to objects just as bundles of properties, with some sort of rules about when it ceased to be that particular bundle (keep 60%?)?
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!
18. Thought / D. Concepts / 4. Structure of Concepts / i. Conceptual priority
Maybe a concept is 'prior' to another if it can be defined without the second concept [Dummett]
     Full Idea: One powerful argument for a thesis that one notion is conceptually prior to another is the possibility of defining the first without reference to the second.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.12)
     A reaction: You'd better check whether you can't also define the second without reference to the first before you rank their priority. And maybe 'conceptual priority' is conceptually prior to 'definition' (i.e. definition needs a knowledge of priority). Help!
An argument for conceptual priority is greater simplicity in explanation [Dummett]
     Full Idea: An argument for conceptual priority is greater simplicity in explanation.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.12)
     A reaction: One might still have to decide priority between two equally simple (or complex) concepts. I begin to wonder whether 'priority' has any other than an instrumental meaning (according to which direction you wish to travel - is London before Edinburgh?).
18. Thought / E. Abstraction / 1. Abstract Thought
Abstract terms are acceptable as long as we know how they function linguistically [Dummett]
     Full Idea: To recognise abstract terms as perfectly proper items of a vocabulary depends upon allowing that all that is necessary for the lawful introduction of a range of expressions into the language is a coherent account of how they are to function in sentences.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.16)
     A reaction: Why can't the 'coherent account' of the sentences include the fact that there must be something there for the terms to refer to? How else are we to eliminate nonsense words which obey good syntactical rules? Cf. Idea 9872.
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
There is no reason why abstraction by equivalence classes should be called 'logical' [Dummett, by Tait]
     Full Idea: Dummett uses the term 'logical abstraction' for the construction of the abstract objects as equivalence classes, but it is not clear why we should call this construction 'logical'.
     From: report of Michael Dummett (Frege philosophy of mathematics [1991]) by William W. Tait - Frege versus Cantor and Dedekind n 14
     A reaction: This is a good objection, and Tait offers a much better notion of 'logical abstraction' (as involving preconditions for successful inference), in Idea 9981.
We arrive at the concept 'suicide' by comparing 'Cato killed Cato' with 'Brutus killed Brutus' [Dummett]
     Full Idea: We arrive at the concept of suicide by considering both occurrences in the sentence 'Cato killed Cato' of the proper name 'Cato' as simultaneously replaceable by another name, say 'Brutus', and so apprehending the pattern common to both sentences.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch.14)
     A reaction: This is intended to illustrate Frege's 'logical abstraction' technique, as opposed to wicked psychological abstraction. The concept of suicide is the pattern 'x killed x'. This is a crucial example if we are to understand abstraction...
18. Thought / E. Abstraction / 8. Abstractionism Critique
To abstract from spoons (to get the same number as the forks), the spoons must be indistinguishable too [Dummett]
     Full Idea: To get units by abstraction, units arrived at by abstraction from forks must the identical to that abstracted from spoons, with no trace of individuality. But if spoons can no longer be differentiated from forks, they can't differ from one another either.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 8)
     A reaction: [compressed] Dummett makes the point better than Frege did. Can we 'think of a fork insofar as it is countable, ignoring its other features'? What are we left thinking of? Frege says it must still be the whole fork. 'Nice fork, apart from the colour'.
19. Language / C. Assigning Meanings / 5. Fregean Semantics
Fregean semantics assumes a domain articulated into individual objects [Dummett]
     Full Idea: A Fregean semantics assumes a domain already determinately articulated into individual objects.
     From: Michael Dummett (Frege philosophy of mathematics [1991], Ch. 8)
     A reaction: A more interesting criticism than most of Dummett's other challenges to the Frege/Davidson view. I am beginning to doubt whether the semantics and the ontology can ever be divorced from the psychology, of thought, interests, focus etc.
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.
27. Natural Reality / C. Space / 3. Points in Space
Why should the limit of measurement be points, not intervals? [Dummett]
     Full Idea: By what right do we assume that the limit of measurement is a point, and not an interval?
     From: Michael Dummett (Frege philosophy of mathematics [1991], 22 'Quantit')