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All the ideas for 'System of Logic', 'What Numbers Could Not Be' and 'Potentiality'

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109 ideas

2. Reason / E. Argument / 1. Argument
Slippery slope arguments are challenges to show where a non-arbitrary boundary lies [Vetter]
     Full Idea: Slippery slope arguments are not intended as demonstrative arguments, but rather as a challenge to show where a boundary is, and to show that the boundary is not arbitrary.
     From: Barbara Vetter (Potentiality [2015], 5.3.3)
     A reaction: [extracted from details of its context] You could respond by saying that a slippery slope levels off, rather than hitting a wall or plunging to perdition.
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / c. System D
Deontic modalities are 'ought-to-be', for sentences, and 'ought-to-do' for predicates [Vetter]
     Full Idea: Deontic modality can be divided into sentence-modifying 'ought-to-be' modals, and predicate-modifying 'ought-to-do' modals.
     From: Barbara Vetter (Potentiality [2015], 6.9.2)
     A reaction: [She cites Brennan 1993] These two seem to correspond to what is 'good' (ought to be), and what is 'right' (ought to do). Since I like that distinction, I also like this one.
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
S5 is undesirable, as it prevents necessities from having contingent grounds [Vetter]
     Full Idea: Wedgwood (2007:220) argues that S5 is undesirable because it excludes that necessary truths may have contingent grounds.
     From: Barbara Vetter (Potentiality [2015], 6.4 n5)
     A reaction: Cameron defends the possibility of necessity grounded in contingency, against Blackburn's denial of it. It's interesting that we choose the logic on the basis of the metaphysics. Shouldn't there be internal reasons for a logic's correctness?
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
The Barcan formula endorses either merely possible things, or makes the unactualised impossible [Vetter]
     Full Idea: Subscribers to the Barcan formula must either be committed to the existence of mere possibilia (such as possible unicorns), or deny many unactualised possibilities of existence.
     From: Barbara Vetter (Potentiality [2015], 7.5)
     A reaction: It increasingly strikes me that the implications of the Barcan formula are ridiculous. Williamson is its champion, but I'm blowed if I can see why. What could a possible unicorn be like? Without them, must we say unicorns are impossible?
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
What physical facts could underlie 0 or 1, or very large numbers? [Frege on Mill]
     Full Idea: What in the world can be the observed fact, or the physical fact, which is asserted in the definition of the number 777864? ...What a pity that Mill did not also illustrate the physical facts underlying the numbers 0 and 1!
     From: comment on John Stuart Mill (System of Logic [1843]) by Gottlob Frege - Grundlagen der Arithmetik (Foundations) §7
     A reaction: I still think patterns could be an empirical foundation for arithmetic, though you still have to grasp the abstract concept of the pattern. An innate capacity to spot resemblance gets you a long way.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / d. and
Combining two distinct assertions does not necessarily lead to a single 'complex proposition' [Mill]
     Full Idea: In 'Caesar is dead, and Brutus is alive' ...there are here two distinct assertions; and we might as well call a street a complex house, as these two propositions a complex proposition.
     From: John Stuart Mill (System of Logic [1843], 1.04.3)
     A reaction: Arthur Prior, in his article on 'tonk', cites this to claim that the mere account of the and-introduction rule does not guarantee the existence of any conjunctive proposition that can result from it. Mill says you are adding a third proposition.
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
All names are names of something, real or imaginary [Mill]
     Full Idea: All names are names of something, real or imaginary.
     From: John Stuart Mill (System of Logic [1843], p.32), quoted by Mark Sainsbury - The Essence of Reference 18.2
     A reaction: Mill's example of of being like a chalk mark on a door, but Sainsbury points out that names can be detached from bearers in a way that chalk marks can't.
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
Mill says names have denotation but not connotation [Mill, by Kripke]
     Full Idea: It is a well known doctrine of Mill that names have denotation but not connotation.
     From: report of John Stuart Mill (System of Logic [1843]) by Saul A. Kripke - Naming and Necessity lectures Lecture 1
     A reaction: A nice starting point for any discussion of the topic. The obvious response is that a name like 'Attila the Hun' seems to have a very vague denotation for most of us, but a rather powerful connotation.
Proper names are just labels for persons or objects, and the meaning is the object [Mill, by Lycan]
     Full Idea: Mill seemed to defend the view that proper names are merely labels for individual persons or objects, and contribute no more than those individuals themselves to the meanings of sentences in which they occur.
     From: report of John Stuart Mill (System of Logic [1843]) by William Lycan - Philosophy of Language
     A reaction: Identity statements can become trivial on this view ('Twain is Clemens'). Modern views have become more sympathetic to Mill, since externalism places meanings outside the head of the speaker.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
There are no such things as numbers [Benacerraf]
     Full Idea: There are no such things as numbers.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], IIIC)
     A reaction: Mill said precisely the same (Idea 9794). I think I agree. There has been a classic error of reification. An abstract pattern is not an object. If I coin a word for all the three-digit numbers in our system, I haven't created a new 'object'.
Numbers can't be sets if there is no agreement on which sets they are [Benacerraf]
     Full Idea: The fact that Zermelo and Von Neumann disagree on which particular sets the numbers are is fatal to the view that each number is some particular set.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], II)
     A reaction: I agree. A brilliantly simple argument. There is the possibility that one of the two accounts is correct (I would vote for Zermelo), but it is not actually possible to prove it.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / c. Priority of numbers
Benacerraf says numbers are defined by their natural ordering [Benacerraf, by Fine,K]
     Full Idea: Benacerraf thinks of numbers as being defined by their natural ordering.
     From: report of Paul Benacerraf (What Numbers Could Not Be [1965]) by Kit Fine - Cantorian Abstraction: Recon. and Defence §5
     A reaction: My intuition is that cardinality is logically prior to ordinality, since that connects better with the experienced physical world of objects. Just as the fact that people have different heights must precede them being arranged in height order.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / f. Cardinal numbers
To understand finite cardinals, it is necessary and sufficient to understand progressions [Benacerraf, by Wright,C]
     Full Idea: Benacerraf claims that the concept of a progression is in some way the fundamental arithmetical notion, essential to understanding the idea of a finite cardinal, with a grasp of progressions sufficing for grasping finite cardinals.
     From: report of Paul Benacerraf (What Numbers Could Not Be [1965]) by Crispin Wright - Frege's Concept of Numbers as Objects 3.xv
     A reaction: He cites Dedekind (and hence the Peano Axioms) as the source of this. The interest is that progression seems to be fundamental to ordianls, but this claims it is also fundamental to cardinals. Note that in the first instance they are finite.
A set has k members if it one-one corresponds with the numbers less than or equal to k [Benacerraf]
     Full Idea: Any set has k members if and only if it can be put into one-to-one correspondence with the set of numbers less than or equal to k.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], I)
     A reaction: This is 'Ernie's' view of things in the paper. This defines the finite cardinal numbers in terms of the finite ordinal numbers. He has already said that the set of numbers is well-ordered.
To explain numbers you must also explain cardinality, the counting of things [Benacerraf]
     Full Idea: I would disagree with Quine. The explanation of cardinality - i.e. of the use of numbers for 'transitive counting', as I have called it - is part and parcel of the explication of number.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], I n2)
     A reaction: Quine says numbers are just a progression, with transitive counting as a bonus. Interesting that Benacerraf identifies cardinality with transitive counting. I would have thought it was the possession of numerical quantity, not ascertaining it.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units
Numbers must be assumed to have identical units, as horses are equalised in 'horse-power' [Mill]
     Full Idea: There is one hypothetical element in the basis of arithmetic, without which none of it would be true: all the numbers are numbers of the same or of equal units. When we talk of forty horse-power, we assume all horses are of equal strength.
     From: John Stuart Mill (System of Logic [1843], 2.6.3)
     A reaction: Of course, horses are not all of equal strength, so there is a problem here for your hard-line empiricist. Mill needs processes of idealisation and abstraction before his empirical arithmetic can get off the ground.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
We can count intransitively (reciting numbers) without understanding transitive counting of items [Benacerraf]
     Full Idea: Learning number words in the right order is counting 'intransitively'; using them as measures of sets is counting 'transitively'. ..It seems possible for someone to learn the former without learning the latter.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], I)
     A reaction: Scruton's nice question (Idea 3907) is whether you could be said to understand numbers if you could only count intransitively. I would have thought such a state contained no understanding at all of numbers. Benacerraf agrees.
Someone can recite numbers but not know how to count things; but not vice versa [Benacerraf]
     Full Idea: It seems that it is possible for someone to learn to count intransitively without learning to count transitively. But not vice versa.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], I)
     A reaction: Benacerraf favours the priority of the ordinals. It is doubtful whether you have grasped cardinality properly if you don't know how to count things. Could I understand 'he has 27 sheep', without understanding the system of natural numbers?
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / g. Applying mathematics
The application of a system of numbers is counting and measurement [Benacerraf]
     Full Idea: The application of a system of numbers is counting and measurement.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], I)
     A reaction: A simple point, but it needs spelling out. Counting seems prior, in experience if not in logic. Measuring is a luxury you find you can indulge in (by imagining your quantity) split into parts, once you have mastered counting.
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers
The only axioms needed are for equality, addition, and successive numbers [Mill, by Shapiro]
     Full Idea: Mill says arithmetic has two axioms, that 'things which are equal to the same thing are equal to each other', and 'equals added to equals make equal sums', plus a definition for each numeral as 'formed by the addition of a unit to the previous number'.
     From: report of John Stuart Mill (System of Logic [1843], p.610?) by Stewart Shapiro - Thinking About Mathematics 4.3
     A reaction: The difficulty here seems to be the definition of 1, and (even worse for an empiricist), of 0. Then he may have a little trouble when he reaches infinity.
For Zermelo 3 belongs to 17, but for Von Neumann it does not [Benacerraf]
     Full Idea: Ernie's number progression is [φ],[φ,[φ]],[φ,[φ],[φ,[φ,[φ]]],..., whereas Johnny's is [φ],[[φ]],[[[φ]]],... For Ernie 3 belongs to 17, not for Johnny. For Ernie 17 has 17 members; for Johnny it has one.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], II)
     A reaction: Benacerraf's point is that there is no proof-theoretic way to choose between them, though I am willing to offer my intuition that Ernie (Zermelo) gives the right account. Seventeen pebbles 'contains' three pebbles; you must pass 3 to count to 17.
The successor of x is either x and all its members, or just the unit set of x [Benacerraf]
     Full Idea: For Ernie, the successor of a number x was the set consisting of x and all the members of x, while for Johnny the successor of x was simply [x], the unit set of x - the set whose only member is x.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], II)
     A reaction: See also Idea 9900. Benacerraf's famous point is that it doesn't seem to make any difference to arithmetic which version of set theory you choose as its basis. I take this to conclusively refute the idea that numbers ARE sets.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / b. Greek arithmetic
Arithmetic is based on definitions, and Sums of equals are equal, and Differences of equals are equal [Mill]
     Full Idea: The inductions of arithmetic are based on so-called definitions (such as '2 and 1 are three'), and on two axioms: The sums of equals are equal, The differences of equals are equal.
     From: John Stuart Mill (System of Logic [1843], 2.6.3)
     A reaction: These are axioms for arithmetical operations, rather than for numbers themselves (which, for Mill, do not require axioms as they are empirically derived).
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Disputes about mathematical objects seem irrelevant, and mathematicians cannot resolve them [Benacerraf, by Friend]
     Full Idea: If two children were brought up knowing two different set theories, they could entirely agree on how to do arithmetic, up to the point where they discuss ontology. There is no mathematical way to tell which is the true representation of numbers.
     From: report of Paul Benacerraf (What Numbers Could Not Be [1965]) by Michèle Friend - Introducing the Philosophy of Mathematics
     A reaction: Benacerraf ends by proposing a structuralist approach. If mathematics is consistent with conflicting set theories, then those theories are not shedding light on mathematics.
No particular pair of sets can tell us what 'two' is, just by one-to-one correlation [Benacerraf, by Lowe]
     Full Idea: Hume's Principle can't tell us what a cardinal number is (this is one lesson of Benacerraf's well-known problem). An infinity of pairs of sets could actually be the number two (not just the simplest sets).
     From: report of Paul Benacerraf (What Numbers Could Not Be [1965]) by E.J. Lowe - The Possibility of Metaphysics 10.3
     A reaction: The drift here is for numbers to end up as being basic, axiomatic, indefinable, universal entities. Since I favour patterns as the basis of numbers, I think the basis might be in a pre-verbal experience, which even a bird might have, viewing its eggs.
If ordinal numbers are 'reducible to' some set-theory, then which is which? [Benacerraf]
     Full Idea: If a particular set-theory is in a strong sense 'reducible to' the theory of ordinal numbers... then we can still ask, but which is really which?
     From: Paul Benacerraf (What Numbers Could Not Be [1965], IIIB)
     A reaction: A nice question about all reductions. If we reduce mind to brain, does that mean that brain is really just mind. To have a direction (up/down?), reduction must lead to explanation in a single direction only. Do numbers explain sets?
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
If any recursive sequence will explain ordinals, then it seems to be the structure which matters [Benacerraf]
     Full Idea: If any recursive sequence whatever would do to explain ordinal numbers suggests that what is important is not the individuality of each element, but the structure which they jointly exhibit.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], IIIC)
     A reaction: This sentence launched the whole modern theory of Structuralism in mathematics. It is hard to see what properties a number-as-object could have which would entail its place in an ordinal sequence.
The job is done by the whole system of numbers, so numbers are not objects [Benacerraf]
     Full Idea: 'Objects' do not do the job of numbers singly; the whole system performs the job or nothing does. I therefore argue that numbers could not be objects at all.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], IIIC)
     A reaction: This thought is explored by structuralism - though it is a moot point where mere 'nodes' in a system (perhaps filled with old bits of furniture) will do the job either. No one ever explains the 'power' of numbers (felt when you do a sudoku). Causal?
The number 3 defines the role of being third in a progression [Benacerraf]
     Full Idea: Any object can play the role of 3; that is, any object can be the third element in some progression. What is peculiar to 3 is that it defines that role, not by being a paradigm, but by representing the relation of any third member of a progression.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], IIIC)
     A reaction: An interesting early attempt to spell out the structuralist idea. I'm thinking that the role is spelled out by the intersection of patterns which involve threes.
Number words no more have referents than do the parts of a ruler [Benacerraf]
     Full Idea: Questions of the identification of the referents of number words should be dismissed as misguided in just the way that a question about the referents of the parts of a ruler would be seen as misguided.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], IIIC)
     A reaction: What a very nice simple point. It would be very strange to insist that every single part of the continuum of a ruler should be regarded as an 'object'.
Mathematical objects only have properties relating them to other 'elements' of the same structure [Benacerraf]
     Full Idea: Mathematical objects have no properties other than those relating them to other 'elements' of the same structure.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], p.285), quoted by Fraser MacBride - Structuralism Reconsidered §3 n13
     A reaction: Suppose we only had one number - 13 - and we all cried with joy when we recognised it in a group of objects. Would that be a number, or just a pattern, or something hovering between the two?
How can numbers be objects if order is their only property? [Benacerraf, by Putnam]
     Full Idea: Benacerraf raises the question how numbers can be 'objects' if they have no properties except order in a particular ω-sequence.
     From: report of Paul Benacerraf (What Numbers Could Not Be [1965], p.301) by Hilary Putnam - Mathematics without Foundations
     A reaction: Frege certainly didn't think that order was their only property (see his 'borehole' metaphor in Grundlagen). It might be better to say that they are objects which only have relational properties.
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
Number-as-objects works wholesale, but fails utterly object by object [Benacerraf]
     Full Idea: The identification of numbers with objects works wholesale but fails utterly object by object.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], IIIC)
     A reaction: This seems to be a glaring problem for platonists. You can stare at 1728 till you are blue in the face, but it only begins to have any properties at all once you examine its place in the system. This is unusual behaviour for an object.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
Different parcels made from three pebbles produce different actual sensations [Mill]
     Full Idea: Three pebbles make different sense impressions in one parcel or in two. That the same pebbles by an alteration of place and arrangement may be made to produce either sensation is not the identical proposition.
     From: John Stuart Mill (System of Logic [1843], 2.6.2)
     A reaction: [compressed] Not quite clear, but Mill seems to be adamant that we really must experience the separation, and not just think what 'may' happen, so Frege is right that Mill is lucky that everything is not 'nailed down'.
'2 pebbles and 1 pebble' and '3 pebbles' name the same aggregation, but different facts [Mill]
     Full Idea: The expressions '2 pebbles and 1 pebble' and '3 pebbles' stand for the same aggregation of objects, but do not stand for the same physical fact. They name the same objects in different states, 'denoting' the same things, with different 'connotations'.
     From: John Stuart Mill (System of Logic [1843], 2.6.2)
     A reaction: Nothing in this would convert me from the analytic view to the empirical view of simple arithmetic, if I were that way inclined. Personally I think of three pebbles as 4 minus 1, because I am haunted by the thought of a missing stone.
3=2+1 presupposes collections of objects ('Threes'), which may be divided thus [Mill]
     Full Idea: 'Three is two and one' presupposes that collections of objects exist, which while they impress the senses thus, ¶¶¶, may be separated into two parts, thus, ¶¶ ¶. This being granted, we term all such parcels Threes.
     From: John Stuart Mill (System of Logic [1843], 2.6.2)
     A reaction: Mill is clearly in trouble here because he sticks to simple arithmetic. He must deal with parcels too big for humans to count, and parcels so big that they could not naturally exist, and that is before you even reach infinite parcels.
Numbers denote physical properties of physical phenomena [Mill]
     Full Idea: The fact asserted in the definition of a number is a physical fact. Each of the numbers two, three, four denotes physical phenomena, and connotes a physical property of those phenomena. Two denotes all pairs of things, and twelve all dozens.
     From: John Stuart Mill (System of Logic [1843], 3.24.5)
     A reaction: The least plausible part of Mill's thesis. Is the fact that a pair of things is fewer than five things also a property? You see two boots, or you see a pair of boots, depending partly on you. Is pure two a visible property? Courage and an onion?
We can't easily distinguish 102 horses from 103, but we could arrange them to make it obvious [Mill]
     Full Idea: 102 horses are not as easily distinguished from 103 as two are from three, yet the horses may be so placed that a difference will be perceptible.
     From: John Stuart Mill (System of Logic [1843], 3.24.5)
     A reaction: More trouble for Mill. We are now moving from the claim that we actually perceive numbers to the claim that we could if we arranged things right. But we would still only see which group of horses was bigger by one, not how many horses there were.
Arithmetical results give a mode of formation of a given number [Mill]
     Full Idea: Every statement of the result of an arithmetical operation is a statement of one of the modes of formation of a given number.
     From: John Stuart Mill (System of Logic [1843], 3.24.5)
     A reaction: Although Mill sticks cautiously to very simple arithmetic, inviting empirical accounts of much higher mathematics, I think the phrase 'modes of formation' of numbers is very helpful. It could take us either into structuralism, or into constructivism.
12 is the cube of 1728 means pebbles can be aggregated a certain way [Mill]
     Full Idea: When we say 12 is the cube of 1728, we affirm that if we had sufficient pebbles, we put them into parcels or aggregates called twelves, and put those twelves into similar collections, and make twelve of these largests parcels, we have the aggregate 1728.
     From: John Stuart Mill (System of Logic [1843], 3.24.5)
     A reaction: There is always hidden modal thinking in Mill's proposals, despite his longing to stick to actual experience. Imagination actually plays a much bigger role in his theory than sense experience does.
Numbers must be of something; they don't exist as abstractions [Mill]
     Full Idea: All numbers must be numbers of something: there are no such things as numbers in the abstract.
     From: John Stuart Mill (System of Logic [1843], p.245?), quoted by Stewart Shapiro - Thinking About Mathematics 4.3
     A reaction: This shows why the concept of 'abstraction' is such a deep problem. Numbers can't be properties of objects, because two boots can become one boot without changing the surviving boot. But why should abstractions have to 'exist'?
Mill says logic and maths is induction based on a very large number of instances [Mill, by Ayer]
     Full Idea: Mill maintained that the truths of logic and mathematics are not necessary or certain, by saying these propositions are inductive generalisations based on an extremely large number of instances.
     From: report of John Stuart Mill (System of Logic [1843]) by A.J. Ayer - Language,Truth and Logic Ch.4
     A reaction: Ayer asserts that they are necessary (but only because they are tautological). I like the idea that maths is the 'science of patterns', but that might lead from an empirical start to a rationalist belief in a priori synthetic truths.
If two black and two white objects in practice produced five, what colour is the fifth one? [Lewis,CI on Mill]
     Full Idea: If Mill has a demon who, every time two things are brought together with two other things, always introduces a fifth, then if two black marbles and two white ones are put in an urn, the demon could choose his color, but there would be more of one colour.
     From: comment on John Stuart Mill (System of Logic [1843]) by C.I. Lewis - A Pragmatic Conception of the A Priori p.367
     A reaction: Nice to see philosophers fighting back against demons. This is a lovely argument against the absurdity of thinking that experience could ever controvert a priori knowledge (though Lewis is no great fan of the latter).
Mill mistakes particular applications as integral to arithmetic, instead of general patterns [Dummett on Mill]
     Full Idea: Mill's mistake is taking particular applications as integral to the sense of arithmetical propositions. But what is integral to arithmetic is the general principle that explains its applicability, and determines the pattern of particular applications.
     From: comment on John Stuart Mill (System of Logic [1843], 2.6) by Michael Dummett - Frege philosophy of mathematics Ch.20
     A reaction: [Dummett is summarising Frege's view] Sounds like a tidy objection, but you still have to connect the general principles and patterns to the physical world. 'Structure' could be the magic word to achieve this.
There are no such things as numbers in the abstract [Mill]
     Full Idea: There are no such things as numbers in the abstract.
     From: John Stuart Mill (System of Logic [1843], 2.6.2)
     A reaction: Depends. Would we want to say that 'horses don't exist' (although each individual horse does exist)? It sounds odd to say of an idea that it doesn't exist, when you are currently thinking about it. I am, however, sympathetic to Mill.
Things possess the properties of numbers, as quantity, and as countable parts [Mill]
     Full Idea: All things possess quantity; consist of parts which can be numbered; and in that character possess all the properties which are called properties of numbers.
     From: John Stuart Mill (System of Logic [1843], 2.6.2)
     A reaction: Here Mill is skating on the very thinnest of ice, and I find myself reluctantly siding with Frege. It is a very optimistic empiricist who hopes to find the numbers actually occurring as properties of experienced objects. A pack of cards, for example.
Numbers have generalised application to entities (such as bodies or sounds) [Mill]
     Full Idea: 'Ten' must mean ten bodies, or ten sounds, or ten beatings of the pulse. But though numbers must be numbers of something, they may be numbers of anything.
     From: John Stuart Mill (System of Logic [1843], 2.6.2)
     A reaction: Mill always prefers things in close proximity, in space or time. 'I've had ten headaches in the last year'. 'There are ten reasons for doubting p'. His second point puts him very close to Aristotle in his view.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
Mill is too imprecise, and is restricted to simple arithmetic [Kitcher on Mill]
     Full Idea: The problem with Mill is that many of his formulations are imprecise, and he only considers the most rudimentary parts of arithmetic.
     From: comment on John Stuart Mill (System of Logic [1843]) by Philip Kitcher - The Nature of Mathematical Knowledge Intro
     A reaction: This is from a fan of Mill, trying to restore his approach in the face of the authoritative and crushing criticisms offered by Frege. I too am a fan of Mill's approach. Patterns can be discerned in arrangements of pebbles. Infinities are a problem.
Empirical theories of arithmetic ignore zero, limit our maths, and need probability to get started [Frege on Mill]
     Full Idea: Mill does not give us a clue as to how to understand the number zero, he limits our mathematical knowledge to the limits of our experience, ..and induction can only give you probability, but that presupposes arithmetical laws.
     From: comment on John Stuart Mill (System of Logic [1843]) by Gottlob Frege - Grundlagen der Arithmetik (Foundations)
     A reaction: This summarises Frege's criticisms of Mill's empirical account of maths. I like 'maths is the science of patterns', in which case zero is just a late-introduced trick (it is hardly a Platonic Form!), and induction is the wrong account to give.
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
Numbers are a very general property of objects [Mill, by Brown,JR]
     Full Idea: Mill held that numbers are a kind of very general property that objects possess.
     From: report of John Stuart Mill (System of Logic [1843], Ch.4) by James Robert Brown - Philosophy of Mathematics
     A reaction: Intuitively this sounds hopeless, because if you place one apple next to another you introduce 'two', but which apple has changed its property? Both? It seems to be a Cambridge change. It isn't a change that would bother the apples. Kitcher pursues this.
Number words are not predicates, as they function very differently from adjectives [Benacerraf]
     Full Idea: The unpredicative nature of number words can be seen by noting how different they are from, say, ordinary adjectives, which do function as predicates.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], II)
     A reaction: He points out that 'x is seventeen' is a rare construction in English, unlike 'x is happy/green/interesting', and that numbers outrank all other adjectives (having to appear first in any string of them).
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
The set-theory paradoxes mean that 17 can't be the class of all classes with 17 members [Benacerraf]
     Full Idea: In no consistent theory is there a class of all classes with seventeen members. The existence of the paradoxes is a good reason to deny to 'seventeen' this univocal role of designating the class of all classes with seventeen members.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], II)
     A reaction: This was Frege's disaster, and seems to block any attempt to achieve logicism by translating numbers into sets. It now seems unclear whether set theory is logic, or mathematics, or sui generis.
7. Existence / A. Nature of Existence / 1. Nature of Existence
The world is either a whole made of its parts, or a container which contains its parts [Vetter]
     Full Idea: We can think of the world as a 'whole' that has everything as its parts, like raisins in a cake, or we can think of the world as a 'container', which is disjoint from everything there is, like a bottle containing water.
     From: Barbara Vetter (Potentiality [2015], 7.3)
     A reaction: [compressed] Space and time seem to have a special role here, and it is hard to think of any other candidates for being the 'container'. I think I will apply my 'what's it made of' test to ontology, and opt for the world as a 'whole'.
7. Existence / C. Structure of Existence / 1. Grounding / b. Relata of grounding
Grounding can be between objects ('relational'), or between sentences ('operational') [Vetter]
     Full Idea: 'Relational' grounding is between entities, best expressed by the two-place predicate 'x grounds y'. 'Operational' grounding is between sentences, best expressed by the two-place sentence operator read as 'because of' or 'in virtue of'.
     From: Barbara Vetter (Potentiality [2015], 1.6)
7. Existence / C. Structure of Existence / 5. Supervenience / d. Humean supervenience
The Humean supervenience base entirely excludes modality [Vetter]
     Full Idea: Humean supervenience excludes modality - the whole modal package - from the supervenience base. The Humean world is, at root, thoroughly non-modal.
     From: Barbara Vetter (Potentiality [2015], 1.2)
     A reaction: This sums up my problem with David Lewis with perfect clarity. He is just excessively empirical. Hume himself also excluded modality from the basic impressions. Locke allows powerful essences (even if they are well hidden).
8. Modes of Existence / B. Properties / 3. Types of Properties
A determinate property must be a unique instance of the determinable class [Vetter]
     Full Idea: The crucial feature of the determinates / determinables relation is that to possess the determinable property, an object must possess exactly one of the determinate properties.
     From: Barbara Vetter (Potentiality [2015], 5.7.2)
     A reaction: This sounds like a determinable being a function, and the determinate being its output. If 'scarlet' is a determinate of the determinables 'red' or 'coloured', it is not obvious that there is only one possible shade of scarlet. This schema oversimplifies.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
I have an 'iterated ability' to learn the violin - that is, the ability to acquire that ability [Vetter]
     Full Idea: I do not have the ability to play the violin. Nor does my desk. Unlike my desk, however, I possess the ability to learn to play the violin - the ability, that is, to acquire the ability to play the violin. I have an 'iterated ability' to play the violin.
     From: Barbara Vetter (Potentiality [2015], 4.6)
     A reaction: An important idea, though the examples are more likely to come from human behaviour than from the non-human physical world.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / c. Dispositions as conditional
We should think of dispositions as 'to do' something, not as 'to do something, if ....' [Vetter]
     Full Idea: We should think in terms of dispositions in terms of the manifestation alone - not as a disposition to ...if..., but as a disposition to ..., full stop.
     From: Barbara Vetter (Potentiality [2015], 1.7)
     A reaction: This way of individuating dispositions seems plausible. Some dispositions only have one trigger, but others have many. All sorts of things are inclined to trigger a human smile, but we are just disposed to smile. Some people smile at disasters.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / d. Dispositions as occurrent
Nomological dispositions (unlike ordinary ones) have to be continually realised [Vetter]
     Full Idea: Nomological dispositions such as electric charge seem different from ordinary dispositions. A particle's being electrically charged is not just a possibility of exerting a certain force. Rather, the particle has to exert a force in certain circumstances.
     From: Barbara Vetter (Potentiality [2015], 2.7)
     A reaction: I can only pull when there is something to pull, but a magnet seems to have a 'field' of attraction which is pullish in character. Does it detect something to pull (like a monad)? Can there be a force which has no object?
8. Modes of Existence / C. Powers and Dispositions / 7. Against Powers
How can spatiotemporal relations be understood in dispositional terms? [Vetter]
     Full Idea: Spatiotemporal relations are a prime example of properties that are difficult to understand in dispositional terms.
     From: Barbara Vetter (Potentiality [2015], 1.6)
     A reaction: [Vetter refers to A.Bird 2007 Ch.8 for an attempt] One approach would be to question whether they are 'properties'. I don't think of relations as properties, even if they are predicates. Is space a property of something?
9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects
Whatever is made up of parts is made up of parts of those parts [Mill]
     Full Idea: Whatever is made up of parts is made up of parts of those parts.
     From: John Stuart Mill (System of Logic [1843], 3.24.5)
     A reaction: Mill considers this principle to be fundamental to the possibilities of arithmetic. Presumably he thought of it as an inductive inference from our dealings with physical objects.
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
The essence is that without which a thing can neither be, nor be conceived to be [Mill]
     Full Idea: The essence of a thing was said to be that without which the thing could neither be, nor be conceived to be.
     From: John Stuart Mill (System of Logic [1843], 1.6.2)
     A reaction: Fine cites this as the 'modal' account of essence, as opposed to the 'definitional' account.
9. Objects / E. Objects over Time / 12. Origin as Essential
Why does origin matter more than development; why are some features of origin more important? [Vetter]
     Full Idea: Not every feature of an individual's origin is plausibly considered necessary, so we can distinguish two questions: 'why origin, rather than development?', and 'why these particular features of origin?'.
     From: Barbara Vetter (Potentiality [2015], 6.2)
     A reaction: [she cites P. Mackie 1998] The point is that exactly where someone was born doesn't seem vital. If it is nothing more than that every contingent object must have an origin, that is not very exciting.
We take origin to be necessary because we see possibilities as branches from actuality [Vetter]
     Full Idea: The plausibility of the necessity of origin is a symptom of our general tendency to think of possibility in terms of the 'branching model' - that unactualised possibilities must branch off from actuality, at some point.
     From: Barbara Vetter (Potentiality [2015], 7.9)
     A reaction: [she cites P. Mackie 1998] It is hard to see how we could flatly deny some possibilities which had absolutely no connection with actuality, and were probably quite unimaginable for us.
9. Objects / F. Identity among Objects / 6. Identity between Objects
Identity statements make sense only if there are possible individuating conditions [Benacerraf]
     Full Idea: Identity statements make sense only in contexts where there exist possible individuating conditions.
     From: Paul Benacerraf (What Numbers Could Not Be [1965], III)
     A reaction: He is objecting to bizarre identifications involving numbers. An identity statement may be bizarre even if we can clearly individuate the two candidates. Winston Churchill is a Mars Bar. Identifying George Orwell with Eric Blair doesn't need a 'respect'.
10. Modality / A. Necessity / 2. Nature of Necessity
Necessity is what will be, despite any alternative suppositions whatever [Mill]
     Full Idea: That which is necessary, that which must be, means that which will be, whatever suppositions we may make in regard to all other things.
     From: John Stuart Mill (System of Logic [1843], 3.06.6)
     A reaction: [Mill discusses causal necessity] This is quoted by McFetridge. This slightly firms up the definition as 'what has to be true', though it makes it dependent on our 'suppositions'. Presumably nothing beyond our powers of supposition could matter either.
Necessity can only mean what must be, without conditions of any kind [Mill]
     Full Idea: If there be any meaning which confessedly belongs to the term necessity, it is unconditionalness. That which is necessary, that which must be, means that which will be whatever supposition we make with regard to other things.
     From: John Stuart Mill (System of Logic [1843], p.339 [1974 ed]), quoted by R.D. Ingthorsson - A Powerful Particulars View of Causation 5.3
     A reaction: 'It is necessary to leave now, if you want to catch the train' is a genuine type of necessity. Mill's type is probably Absolute necessity, to which nothing could make any difference. Or Metaphysical necessity, determined by all things.
The modern revival of necessity and possibility treated them as special cases of quantification [Vetter]
     Full Idea: Necessity and possibility had a revival with the development of modal logic, treating them as special cases of the existential and universal quantifiers, ranging over an infinity of possible worlds.
     From: Barbara Vetter (Potentiality [2015], 1.1)
     A reaction: The problem seems to be that possible worlds offer a very useful and interesting 'model' of modality, but say nothing at all about its nature. Any more than a weather map will show you what weather is.
It is necessary that p means that nothing has the potentiality for not-p [Vetter]
     Full Idea: Necessities mark the limits of the potentialities that objects have. More precisely, it is necessary that p just in case nothing has, or had, or will have a potentiality to be such that not-p.
     From: Barbara Vetter (Potentiality [2015], 6.2)
     A reaction: [See Vetter's other ideas for her potentiality account of modality] If we wish to build a naturalistic account of modality (and if you don't want that then your untethered metaphysics will drift away in logical space) then this is the way to go.
10. Modality / B. Possibility / 1. Possibility
Possibilities are potentialities of actual things, but abstracted from their location [Vetter]
     Full Idea: When we speak of possibility, we speak of potentiality in abstraction from its possessor; a possibility is a potentiality somewhere or other in the world, no matter where.
     From: Barbara Vetter (Potentiality [2015], 6.1)
     A reaction: I note that, as so often, this is psychological abstraction, which is usually sneered at by modern philosophers (e.g. Geach), and yet is employed all the time. This is Vetter's key thesis, which I like.
All possibility is anchored in the potentiality of individual objects [Vetter]
     Full Idea: Potentiality is, metaphorically speaking, possibility anchored in individual objects; I claim that all possibility is thus anchored in some individual object(s) or other.
     From: Barbara Vetter (Potentiality [2015], 1.1)
     A reaction: This will be fine for specific physical possibilities, but may become tricky for possibilities that are increasingly abstract, or universal, or idealised. I agree with the general approach. Anchor modality in reality (which is physical!).
Possibility is a generalised abstraction from the potentiality of its bearer [Vetter]
     Full Idea: We should think of possibility as potentiality in abstraction from its bearer. So 'it is possible that p' is defined as 'something has an iterated potentiality for it to be the case that p'.
     From: Barbara Vetter (Potentiality [2015], 1.4)
     A reaction: If possibilities are abstractions from potentialities, I am inclined the treat potentialities as abstractions from dispositions, and dispositions (and properties) as abstractions from powers. Powers are not abstractions - they are the reality.
10. Modality / B. Possibility / 4. Potentiality
Potentiality is the common genus of dispositions, abilities, and similar properties [Vetter]
     Full Idea: Potentiality can now be recognised as the common genus of dispositions and such related properties as abilities.
     From: Barbara Vetter (Potentiality [2015], 4.1)
     A reaction: This is the reason why Vetter defends a metaphysics of modality based on potentialities, rather than on narrower concepts such as dispositions, powers or essences. She can evade the problems which those narrower concepts raise.
Water has a potentiality to acquire a potentiality to break (by freezing) [Vetter]
     Full Idea: Water has no potentiality to break. But water has a potentiality to be frozen and turn into ice, which does have a potentiality to break. So water has a potentiality to acquire a potentiality to break.
     From: Barbara Vetter (Potentiality [2015], 4.6)
     A reaction: Thus potentially has an 'iterated' character to it, and an appropriate modal logic for it will have to allow for those iterations. She suggests a version of System T modal logic.
A potentiality may not be a disposition, but dispositions are strong potentialities [Vetter, by Friend/Kimpton-Nye]
     Full Idea: Although not all potentialities are dispositions, Vetter claims that all dispositions are potentialities which are had to a sufficiently high degree.
     From: report of Barbara Vetter (Potentiality [2015]) by Friend/Kimpton-Nye - Dispositions and Powers 2.4.2
     A reaction: This sounds plausible. A potentiality could be faint or negligible, but once it is a serious possibility it becomes a 'disposition'. ...I suppose. But if the meteor is probably going to hit my house, it doesn't mean it has a disposition to do so.
Potentiality does the explaining in metaphysics; we don't explain it away or reduce it [Vetter]
     Full Idea: This book is a plea for recognising potentiality as an explanans in the metaphysics of modality, rather than as something in need of explanation or reduction.
     From: Barbara Vetter (Potentiality [2015], 1.1)
     A reaction: Something has to do the explaining, and it is obviously much better to have some aspect of the real world do the job, rather than remote abstractions such as laws, possible worlds or Forms. Personally I like the potentiality of 'powers'.
Potentiality logic is modal system T. Stronger systems collapse iterations, and necessitate potentials [Vetter]
     Full Idea: The logic for potentiality corresponds to modal system T, the minimum for metaphysics. The S4 axiom ◊◊φ → ◊φ says iterated potentialities collapse, and the S5 ◊φ → □◊φ says potentialities can't be lost.
     From: Barbara Vetter (Potentiality [2015], 5.9)
     A reaction: [compressed] This seems persuasive. I nice example of modern analytic metaphysics, that you have to find a logic that suits your theory. N.Salmon defends system T for all of metaphysics, though most people favour S5.
There are potentialities 'to ...', but possibilities are 'that ....'. [Vetter]
     Full Idea: Potentialities are 'potentialities to ....', while possibilities are 'possibilities that ....'.
     From: Barbara Vetter (Potentiality [2015], 6.4)
     A reaction: This feels a bit like a stipulation, rather than a precise description of normal usage. That said, it is quite a nice distinction. It sounds as if an event follows a potentiality, and a state of affairs follows a possibility. Active and passive?
Potentialities may be too weak to count as 'dispositions' [Vetter]
     Full Idea: Potentialities may get exercised despite having a degree that is too low for them to qualify as dispositions.
     From: Barbara Vetter (Potentiality [2015], 5.7.4)
     A reaction: The key reason why her book is called 'Potentialities', rather than 'Dispositions'. She still wants to offer a naturalistic picture which ties potentialities to individual objects, but I am wondering whether potentialities are too abstract for the job.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / c. Worlds as propositions
If worlds are sets of propositions, how do we know which propositions are genuinely possible? [Vetter]
     Full Idea: If possible worlds are sets of propositions, we need some way to distinguish those sets of propositions that do from those that do not correspond to genuine possibilities.
     From: Barbara Vetter (Potentiality [2015], 1.2)
     A reaction: The idea of a 'genuine' possibility does not seem to play a role in the conceptual scheme of those who treat possibility entirely in terms of possible worlds. If possibility is primitive, or is a set of worlds, there can be no criterion for 'genuine'.
10. Modality / E. Possible worlds / 3. Transworld Objects / e. Possible Objects
Are there possible objects which nothing has ever had the potentiality to produce? [Vetter]
     Full Idea: Is it not possible that there be objects with (natural) properties that no actual thing ever had the potentiality to have, to produce, or constitute? (Call such properties 'super-alien properties').
     From: Barbara Vetter (Potentiality [2015], 7.5)
     A reaction: This is a problem for her potentiality account of possibility. Her solution is (roughly) to either deny the super-aliens, or have chains of iterated possibility which take this case back to actuality. That sounds OK to me.
12. Knowledge Sources / B. Perception / 6. Inference in Perception
Most perception is one-tenth observation and nine-tenths inference [Mill]
     Full Idea: In almost every act of our perceiving faculties, observation and inference are intimately blended. What we are said to observe is usually a compound result, of which one-tenth may be observation, and the remaining nine-tenths inference.
     From: John Stuart Mill (System of Logic [1843], 4.1.2), quoted by Peter Lipton - Inference to the Best Explanation (2nd) 11 'The scientific'
     A reaction: We seem to think that his kind of observation is a great realisation of twentieth century thought, but thoughtful empiricists spotted it much earlier.
12. Knowledge Sources / D. Empiricism / 4. Pro-Empiricism
Clear concepts result from good observation, extensive experience, and accurate memory [Mill]
     Full Idea: The principle requisites of clear conceptions, are habits of attentive observation, an extensive experience, and a memory which receives and retains an exact image of what is observed.
     From: John Stuart Mill (System of Logic [1843], 4.2.5)
     A reaction: Empiricists are always crying out for people to 'attend to the evidence', and this is the deeper reason why. Not only will one know the world better in a direct way, but one will actually think more clearly. Darwin is the perfect model for this.
14. Science / A. Basis of Science / 5. Anomalies
Inductive generalisation is more reliable than one of its instances; they can't all be wrong [Mill]
     Full Idea: A general proposition collected from particulars is often more certainly true than any one of the particular propositions from which, by an act of induction, it was inferred. It might be erroneous in any instance, but cannot be erroneous in all of them.
     From: John Stuart Mill (System of Logic [1843], 4.1.2), quoted by Peter Lipton - Inference to the Best Explanation (2nd) 11 'The scientific'
     A reaction: One anomaly can be ignored, but several can't, especially if the anomalies agree.
14. Science / C. Induction / 1. Induction
The whole theory of induction rests on causes [Mill]
     Full Idea: The notion of cause is the root of the whole theory of induction.
     From: John Stuart Mill (System of Logic [1843], 3.05.2), quoted by Peter Lipton - Inference to the Best Explanation (2nd) 08 'From cause'
     A reaction: This sounds much better to me than the Humean view that it rests on the psychology of regularity and habit. However, maybe Hume describes induction, and Mill is adding abduction (inference to the best explanation).
Mill's methods (Difference,Agreement,Residues,Concomitance,Hypothesis) don't nail induction [Mill, by Lipton]
     Full Idea: The Method of Difference, and even the full four 'experimental methods' (Difference, Agreement, Residues and Concomitant Variations) are agreed on all sides to be incomplete accounts of inductive inference. Mill himself added the Method of Hypothesis.
     From: report of John Stuart Mill (System of Logic [1843], 3.14.4-5) by Peter Lipton - Inference to the Best Explanation (2nd) 08 'Improved'
     A reaction: If induction is just 'learning from experience' (my preferred definition) then there is unlikely to be a precise account of its methods. Mill seems to have done a lovely job.
14. Science / D. Explanation / 1. Explanation / a. Explanation
Surprisingly, empiricists before Mill ignore explanation, which seems to transcend experience [Mill, by Ruben]
     Full Idea: It is surprising that no empiricist philosopher before Mill turned in an explicit way to the scrutiny of the concept of explanation, which had …every appearance of being experience-transcendent.
     From: report of John Stuart Mill (System of Logic [1843]) by David-Hillel Ruben - Explaining Explanation Ch 4
     A reaction: Yes indeed! This is why explanation is absolutely basic, to philosophy and to human understanding. The whole of philosophy is a quest for explanations, so to be strictly empirical about it strikes me as crazy.
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
Explanations by disposition are more stable and reliable than those be external circumstances [Vetter]
     Full Idea: Patterns of behaviour may be explained by circumstances external to the individual, but dispositional explanations, based on the instrinsic make-up of individuals are typically more reliable and stable.
     From: Barbara Vetter (Potentiality [2015], 3.5)
     A reaction: [compressed] This is very nice support for the view I have been defending. She doesn't deal in essences, and prefers 'potentialities' (as broader) to 'dispositions'. The point is to explain events by the natures of the ingredients.
Grounding is a kind of explanation, suited to metaphysics [Vetter]
     Full Idea: Grounding is a kind of explanation - and specifically, the kind of metaphysical explanation that metaphysicians are after.
     From: Barbara Vetter (Potentiality [2015], 4.5)
     A reaction: Depending on how you interpret 'grounding', it is plausible that it is the sort of explanation that physicists and economists are after as well. If the aim is to understand the structure of everything, the target is to know what grounds what.
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
Explanation is fitting of facts into ever more general patterns of regularity [Mill, by Ruben]
     Full Idea: For Mill, explanation was always the fitting of facts into ever more general patterns of regularity.
     From: report of John Stuart Mill (System of Logic [1843]) by David-Hillel Ruben - Explaining Explanation Ch 6
     A reaction: This seems to nicely capture the standard empirical approach to explanation. If you say that this fitting in doesn't explain much, the answer (I think) is that this is the best we can do.
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
Causal inference is by spotting either Agreements or Differences [Mill, by Lipton]
     Full Idea: The best known account of causal inference is Mill's Method of Agreement (only one antecedent is shared by the effects), and the Method of Difference (there is only one difference prior to the effect occurring or not occurring).
     From: report of John Stuart Mill (System of Logic [1843], 3.07) by Peter Lipton - Inference to the Best Explanation (2nd) 01 'Descr'
     A reaction: [my summary of Lipton's summary of Mill]
14. Science / D. Explanation / 3. Best Explanation / a. Best explanation
The Methods of Difference and of Agreement are forms of inference to the best explanation [Mill, by Lipton]
     Full Idea: Like Mill's Method of Difference, applications of the Method of Agreement are naturally construed as inferences to the best explanation.
     From: report of John Stuart Mill (System of Logic [1843], 3.07/8) by Peter Lipton - Inference to the Best Explanation (2nd) 06 'The Method'
     A reaction: This sort of thoroughly sensible approach to understanding modes of investigation has been absurdly sidelined by the desire to 'deduce' observations from 'laws'. Scientific investigation is no different from enquiry in daily life. Where are my glasses?
15. Nature of Minds / C. Capacities of Minds / 3. Abstraction by mind
We can focus our minds on what is common to a whole class, neglecting other aspects [Mill]
     Full Idea: The voluntary power which the mind has, of attending to one part of what is present at any moment, and neglecting another part, enables us to be unaffected by anything in the idea which is not really common to the whole class.
     From: John Stuart Mill (System of Logic [1843], 4.2.1)
     A reaction: There is a question for empiricists of whether abstraction is a 'voluntary' power or a mechanical one. Associationism presents it as more mechanical. I would say, with Mill, that it is a least partly voluntary, and even rational.
15. Nature of Minds / C. Capacities of Minds / 7. Seeing Resemblance
We don't recognise comparisons by something in our minds; the concepts result from the comparisons [Mill]
     Full Idea: It is not a law of our intellect that in comparing things and noting their agreements we recognise as realized in the outward world something we already had in our minds. The conception found its way to us as the result of such a comparison.
     From: John Stuart Mill (System of Logic [1843], 4.2.2)
     A reaction: He recognises, of course, that this gradually becomes a two-way process. In the physicalist view of things, it is not really of great importance which concepts are hard-wired, and which constructed culturally or through perception.
18. Thought / E. Abstraction / 1. Abstract Thought
General conceptions are a necessary preliminary to Induction [Mill]
     Full Idea: Forming general conceptions is a necessary preliminary to Induction.
     From: John Stuart Mill (System of Logic [1843], 4.2.1)
     A reaction: A key link in the framework of empirical philosophies, which gets us from experience to science. Induction is the very process of generalisation. We can't bring a concept like 'evolution' to preliminary observations, so it must be formulated inductively.
The study of the nature of Abstract Ideas does not belong to logic, but to a different science [Mill]
     Full Idea: The metaphysical inquiry into the nature and composition of what have been called Abstract Ideas, or in other words, of the notions which answer in the mind to classes and to general names, belongs not to Logic, but to a different science.
     From: John Stuart Mill (System of Logic [1843], 4.2.1)
     A reaction: He doesn't name the science, but the point here seems to be precisely what Frege so vigorously disagreed with. I would say that the state of being 'abstract' has logical aspects, and can be partly described by logic, but that Mill is basically right.
26. Natural Theory / C. Causation / 8. Particular Causation / c. Conditions of causation
A cause is the total of all the conditions which inevitably produce the result [Mill]
     Full Idea: A cause is the sum total of the conditions positive and negative taken together ...which being realized, the consequent invariably follows.
     From: John Stuart Mill (System of Logic [1843]), quoted by Donald Davidson - Causal Relations §1
     A reaction: This has obvious problems. The absence of Napoleon was a cause of the English Civil War. The Big Bang was a cause of, well, every event. As Davidson notes, some narrowing down is needed.
26. Natural Theory / C. Causation / 8. Particular Causation / d. Selecting the cause
Causes and conditions are not distinct, because we select capriciously from among them [Mill]
     Full Idea: Nothing can better show the absence of any scientific ground for the distinction between the cause of a phenomena and its conditions, than the capricious manner in which we select from among the conditions that which we choose to denominate the cause.
     From: John Stuart Mill (System of Logic [1843]), quoted by Jonathan Schaffer - The Metaphysics of Causation 2.2
     A reaction: [ref Mill p.196, 1846 edn] Schaffer gives this as the main argument for the 'no-basis' view of the selection of what causes an event. The usual thought is that it is entirely our immediate interests which make us select THE cause. Not convinced.
The strict cause is the total positive and negative conditions which ensure the consequent [Mill]
     Full Idea: The cause, philosophically speaking, is the sum total of the conditions, positive and negative taken together; the whole of the contigencies of every description, which being realized, the consequent invariably follows.
     From: John Stuart Mill (System of Logic [1843], 3.05.3)
     A reaction: This somewhat notorious remark is not going to be much help in a law court or a laboratory. It is that view which says that the Big Bang must be included in every causal list ever compiled. Well, yes...
26. Natural Theory / C. Causation / 9. General Causation / a. Constant conjunction
Causation is just invariability of succession between every natural fact and a preceding fact [Mill]
     Full Idea: The Law of Causation, the recognition of which is the main pillar of inductive science, is but the familiar truth, that invariability of succession is found by observation between every fact in nature and some other fact which has preceded it.
     From: John Stuart Mill (System of Logic [1843], 3.5.2), quoted by Bertrand Russell - On the Notion of Cause p.178
     A reaction: Note that Mill rests causation on 'facts'. In the empiricist Mill endorsing the views of Hume. Russell attacks the bogus claim that science rests on causation. Personally I think Mill's view is incorrect.
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
A cause is an antecedent which invariably and unconditionally leads to a phenomenon [Mill]
     Full Idea: We may define the cause of a phenomenon to be the antecedent, or the concurrence of the antecedents, on which it is invariably and unconditionally consequent.
     From: John Stuart Mill (System of Logic [1843], 3.05.6)
     A reaction: This ignores the possibility of the world ending just before the effect occurs, the 'ceteris paribus' clause. If it only counts as a cause if the effect has actually occurred, we begin to suspect tautology.
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
Mill's regularity theory of causation is based on an effect preceded by a conjunction of causes [Mill, by Psillos]
     Full Idea: Millian causation is a version of the Regularity Theory, but with the addition that when claiming that an effect invariably follows from the cause, the cause is not a single factor, but a whole conjunction of necessary and sufficient conditions.
     From: report of John Stuart Mill (System of Logic [1843], p.217) by Stathis Psillos - Causation and Explanation §2.2
     A reaction: Psillos endorses this as an improvement on Hume. But while we may replicate one event preceding another to get regularity, groups of events are hardly ever identical, so no precise pattern will ever be seen.
In Mill's 'Method of Agreement' cause is the common factor in a range of different cases [Mill, by Psillos]
     Full Idea: In Mill's 'Method of Agreement' the cause is the common factor in a number of otherwise different cases in which the effect occurs.
     From: report of John Stuart Mill (System of Logic [1843], p.255) by Stathis Psillos - Causation and Explanation §2.3
     A reaction: This looks more likely to be good evidence for the cause of an event, rather than a definition of what a cause actually is. Suppose a footballer only scores if and only if I go to watch him?
In Mill's 'Method of Difference' the cause is what stops the effect when it is removed [Mill, by Psillos]
     Full Idea: In Mill's 'Method of Difference' the cause is the factor which is different in two cases which are similar, except that in one the effect occurs, and in the other it doesn't.
     From: report of John Stuart Mill (System of Logic [1843], p.256) by Stathis Psillos - Causation and Explanation §2.3
     A reaction: Like the Method of Agreement, this is a good test, but is unlikely to be a conclusive hallmark of causation. A footballer may never score unless I go to watch him. I become his lucky mascot…
26. Natural Theory / D. Laws of Nature / 4. Regularities / b. Best system theory
What are the fewest propositions from which all natural uniformities could be inferred? [Mill]
     Full Idea: What are the fewest general propositions from which all the uniformities which exist in the universe might be deductively inferred?
     From: John Stuart Mill (System of Logic [1843], 3.4.1)
     A reaction: This is the germ of the Mill-Ramsey-Lewis view.
26. Natural Theory / D. Laws of Nature / 5. Laws from Universals
The view that laws are grounded in substance plus external necessity doesn't suit dispositionalism [Vetter]
     Full Idea: The Armstrong/Tooley/Dretske view, which takes laws to be substantial but grounded in a relation of nomic necessitation external to the properties themselves, is not an attractive option for the dispositionalist.
     From: Barbara Vetter (Potentiality [2015], 7.8)
     A reaction: The point is that the dispositionalist sees laws as grounded in the properties. I prefer her other option, of dispositionalism plus a 'shallow' view of laws (which she attributes to Mumford). The laws are as Lewis says, but powers explain them.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / b. Scientific necessity
Dispositional essentialism allows laws to be different, but only if the supporting properties differ [Vetter]
     Full Idea: Even on the dispositional essentialist view the world might have been governed by different laws, if those laws involved different properties. What is excluded is the possibility of different laws involving the same properties as our actual laws.
     From: Barbara Vetter (Potentiality [2015], 7.8)
     A reaction: Important. Critics of dispositional essentialism accuse it of promoting the idea that the laws of nature are necessary, a claim for which we obviously have no evidence. I prefer to say they are necessary given that 'stuff', rather than those properties.
27. Natural Reality / D. Time / 1. Nature of Time / f. Eternalism
If time is symmetrical between past and future, why do they look so different? [Vetter]
     Full Idea: Any defender of the symmetry of time will have to provide some explanation of the obstinate appearance that the future is very different from the past.
     From: Barbara Vetter (Potentiality [2015], 5.8)
     A reaction: Presumably you have to say that it is all there, but only one end of the time spectrum is revealed to us, namely the past. But how do we get this uniquely lopsided view? Being an ominiscient god is more obvious than being a lopsided human.
27. Natural Reality / D. Time / 1. Nature of Time / h. Presentism
Presentists explain cross-temporal relations using surrogate descriptions [Vetter]
     Full Idea: Presentists usually deal with the lack of cross-temporal relations by the construction of a surrogate, by way of paraphrasing the objectionable relation ascriptions. 'I admire Socrates' becomes 'I admire the Socrates properties'.
     From: Barbara Vetter (Potentiality [2015], 7.9)
     A reaction: [compressed. The cites Markosian 2004:63] Why can't I just say 'I admire Socrates, who no longer exists'? The present includes tensed facts, and memories and evidence-based theories. Admiring is not a direct relation between objects.