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All the ideas for 'Frege's Concept of Numbers as Objects', 'Just and Unjust Wars' and 'Ontology'

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83 ideas

1. Philosophy / C. History of Philosophy / 1. History of Philosophy
We can only learn from philosophers of the past if we accept the risk of major misrepresentation [Wright,C]
     Full Idea: We can learn from the work of philosophers of other periods only if we are prepared to run the risk of radical and almost inevitable misrepresentation of his thought.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Pref)
     A reaction: This sounds about right, and a motto for my own approach to Aristotle and Leibniz, but I see the effort as more collaborative than this suggests. Professional specialists in older philosophers are a vital part of the team. Read them!
2. Reason / C. Styles of Reason / 1. Dialectic
The best way to understand a philosophical idea is to defend it [Wright,C]
     Full Idea: The most productive way in which to attempt an understanding of any philosophical idea is to work on its defence.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.vii)
     A reaction: Very nice. The key point is that this brings greater understanding than working on attacking an idea, which presumably has the dangers of caricature, straw men etc. It is the Socratic insight that dialectic is the route to wisdom.
2. Reason / D. Definition / 7. Contextual Definition
The attempt to define numbers by contextual definition has been revived [Wright,C, by Fine,K]
     Full Idea: Frege gave up on the attempt to introduce natural numbers by contextual definition, but the project has been revived by neo-logicists.
     From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Kit Fine - The Limits of Abstraction II
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
The modal logic of C.I.Lewis was only interpreted by Kripke and Hintikka in the 1960s [Jacquette]
     Full Idea: The modal syntax and axiom systems of C.I.Lewis (1918) were formally interpreted by Kripke and Hintikka (c.1965) who, using Z-F set theory, worked out model set-theoretical semantics for modal logics and quantified modal logics.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: A historical note. The big question is always 'who cares?' - to which the answer seems to be 'lots of people', if they are interested in precision in discourse, in artificial intelligence, and maybe even in metaphysics. Possible worlds started here.
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic describes inferences between sentences expressing possible properties of objects [Jacquette]
     Full Idea: It is fundamental that logic depends on logical possibilities, in which logically possible properties are predicated of logically possible objects. Logic describes inferential structures among sentences expressing the predication of properties to objects.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: If our imagination is the only tool we have for assessing possibilities, this leaves the domain of logic as being a bit subjective. There is an underlying Platonism to the idea, since inferences would exist even if nothing else did.
5. Theory of Logic / C. Ontology of Logic / 2. Platonism in Logic
Logic is not just about signs, because it relates to states of affairs, objects, properties and truth-values [Jacquette]
     Full Idea: At one level logic can be regarded as a theory of signs and formal rules, but we cannot neglect the meaning of propositions as they relate to states of affairs, and hence to possible properties and objects... there must be the possibility of truth-values.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: Thus if you define logical connectives by truth tables, you need the concept of T and F. You could, though, regard those too as purely formal (like 1 and 0 in electronics). But how do you decide which propositions are 1, and which are 0?
5. Theory of Logic / F. Referring in Logic / 1. Naming / d. Singular terms
An expression refers if it is a singular term in some true sentences [Wright,C, by Dummett]
     Full Idea: For Wright, an expression refers to an object if it fulfils the 'syntactic role' of a singular term, and if we have fixed the truth-conditions of sentences containing it in such a way that some of them come out true.
     From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Michael Dummett - Frege philosophy of mathematics Ch.15
     A reaction: Much waffle is written about reference, and it is nice to hear of someone actually trying to state the necessary and sufficient conditions for reference to be successful. So is it possible for 'the round square' to ever refer? '...is impossible to draw'
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / c. Theory of definite descriptions
On Russell's analysis, the sentence "The winged horse has wings" comes out as false [Jacquette]
     Full Idea: It is infamous that on Russell's analysis the sentences "The winged horse has wings" and "The winged horse is a horse" are false, because in the extant domain of actual existent entities there contingently exist no winged horses
     From: Dale Jacquette (Ontology [2002], Ch. 6)
     A reaction: This is the best objection I have heard to Russell's account of definite descriptions. The connected question is whether 'quantifies over' is really a commitment to existence. See Idea 6067.
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / d. Russell's paradox
Can a Barber shave all and only those persons who do not shave themselves? [Jacquette]
     Full Idea: The Barber Paradox refers to the non-existent property of being a barber who shaves all and only those persons who do not shave themselves.
     From: Dale Jacquette (Ontology [2002], Ch. 9)
     A reaction: [Russell spotted this paradox, and it led to his Theory of Types]. This paradox may throw light on the logic of indexicals. What does "you" mean when I say to myself "you idiot!"? If I can behave as two persons, so can the barber.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
Number theory aims at the essence of natural numbers, giving their nature, and the epistemology [Wright,C]
     Full Idea: In the Fregean view number theory is a science, aimed at those truths furnished by the essential properties of zero and its successors. The two broad question are then the nature of the objects, and the epistemology of those facts.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro)
     A reaction: [compressed] I pounce on the word 'essence' here (my thing). My first question is about the extent to which the natural numbers all have one generic essence, and the extent to which they are individuals (bless their little cotton socks).
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / c. Priority of numbers
One could grasp numbers, and name sizes with them, without grasping ordering [Wright,C]
     Full Idea: Someone could be clear about number identities, and distinguish numbers from other things, without conceiving them as ordered in a progression at all. The point of them would be to make comparisons between sizes of groups.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xv)
     A reaction: Hm. Could you grasp size if you couldn't grasp which of two groups was the bigger? What's the point of noting that I have ten pounds and you only have five, if you don't realise that I have more than you? You could have called them Caesar and Brutus.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / d. Counting via concepts
Instances of a non-sortal concept can only be counted relative to a sortal concept [Wright,C]
     Full Idea: The invitation to number the instances of some non-sortal concept is intelligible only if it is relativised to a sortal.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i)
     A reaction: I take this to be an essentially Fregean idea, as when we count the boots when we have decided whether they fall under the concept 'boot' or the concept 'pair'. I also take this to be the traditional question 'what units are you using'?
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
Wright thinks Hume's Principle is more fundamental to cardinals than the Peano Axioms are [Wright,C, by Heck]
     Full Idea: Wright is claiming that HP is a special sort of truth in some way: it is supposed to be the fundamental truth about cardinality; ...in particular, HP is supposed to be more fundamental, in some sense than the Dedekind-Peano axioms.
     From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Richard G. Heck - Cardinality, Counting and Equinumerosity 1
     A reaction: Heck notes that although PA can be proved from HP, HP can be proven from PA plus definitions, so direction of proof won't show fundamentality. He adds that Wright thinks HP is 'more illuminating'.
There are five Peano axioms, which can be expressed informally [Wright,C]
     Full Idea: Informally, Peano's axioms are: 0 is a number, numbers have a successor, different numbers have different successors, 0 isn't a successor, properties of 0 which carry over to successors are properties of all numbers.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro)
     A reaction: Each statement of the famous axioms is slightly different from the others, and I have reworded Wright to fit him in. Since the last one (the 'induction axiom') is about properties, it invites formalization in second-order logic.
Number truths are said to be the consequence of PA - but it needs semantic consequence [Wright,C]
     Full Idea: The intuitive proposal is the essential number theoretic truths are precisely the logical consequences of the Peano axioms, ...but the notion of consequence is a semantic one...and it is not obvious that we possess a semantic notion of the requisite kind.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro)
     A reaction: (Not sure I understand this, but it is his starting point for rejecting PA as the essence of arithmetic).
What facts underpin the truths of the Peano axioms? [Wright,C]
     Full Idea: We incline to think of the Peano axioms as truths of some sort; so there has to be a philosophical question how we ought to conceive of the nature of the facts which make those statements true.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro)
     A reaction: [He also asks about how we know the truths]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
Sameness of number is fundamental, not counting, despite children learning that first [Wright,C]
     Full Idea: We teach our children to count, sometimes with no attempt to explain what the sounds mean. Doubtless it is this habit which makes it so natural to think of the number series as fundamental. Frege's insight is that sameness of number is fundamental.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xv)
     A reaction: 'When do children understand number?' rather than when they can recite numerals. I can't make sense of someone being supposed to understand number without a grasp of which numbers are bigger or smaller. To make 13='15' do I add or subtract?
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / d. Hume's Principle
We derive Hume's Law from Law V, then discard the latter in deriving arithmetic [Wright,C, by Fine,K]
     Full Idea: Wright says the Fregean arithmetic can be broken down into two steps: first, Hume's Law may be derived from Law V; and then, arithmetic may be derived from Hume's Law without any help from Law V.
     From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Kit Fine - The Limits of Abstraction I.4
     A reaction: This sounds odd if Law V is false, but presumably Hume's Law ends up as free-standing. It seems doubtful whether the resulting theory would count as logic.
Frege has a good system if his 'number principle' replaces his basic law V [Wright,C, by Friend]
     Full Idea: Wright proposed removing Frege's basic law V (which led to paradox), replacing it with Frege's 'number principle' (identity of numbers is one-to-one correspondence). The new system is formally consistent, and the Peano axioms can be derived from it.
     From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Michčle Friend - Introducing the Philosophy of Mathematics 3.7
     A reaction: The 'number principle' is also called 'Hume's principle'. This idea of Wright's resurrected the project of logicism. The jury is ought again... Frege himself questioned whether the number principle was a part of logic, which would be bad for 'logicism'.
Wright says Hume's Principle is analytic of cardinal numbers, like a definition [Wright,C, by Heck]
     Full Idea: Wright intends the claim that Hume's Principle (HP) embodies an explanation of the concept of number to imply that it is analytic of the concept of cardinal number - so it is an analytic or conceptual truth, much as a definition would be.
     From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Richard G. Heck - Cardinality, Counting and Equinumerosity 1
     A reaction: Boolos is quoted as disagreeing. Wright is claiming a fundamental truth. Boolos says something can fix the character of something (as yellow fixes bananas), but that doesn't make it 'fundamental'. I want to defend 'fundamental'.
It is 1-1 correlation of concepts, and not progression, which distinguishes natural number [Wright,C]
     Full Idea: What is fundamental to possession of any notion of natural number at all is not the knowledge that the numbers may be arrayed in a progression but the knowledge that they are identified and distinguished by reference to 1-1 correlation among concepts.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xv)
     A reaction: My question is 'what is the essence of number?', and my inclination to disagree with Wright on this point suggests that the essence of number is indeed caught in the Dedekind-Peano axioms. But what of infinite numbers?
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / e. Caesar problem
If numbers are extensions, Frege must first solve the Caesar problem for extensions [Wright,C]
     Full Idea: Identifying numbers with extensions will not solve the Caesar problem for numbers unless we have already solved the Caesar problem for extensions.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xiv)
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
Number platonism says that natural number is a sortal concept [Wright,C]
     Full Idea: Number-theoretic platonism is just the thesis that natural number is a sortal concept.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i)
     A reaction: See Crispin Wright on sortals to expound this. An odd way to express platonism, but he is presenting the Fregean version of it.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
We can't use empiricism to dismiss numbers, if numbers are our main evidence against empiricism [Wright,C]
     Full Idea: We may not be able to settle whether some general form of empiricism is correct independently of natural numbers. It might be precisely our grasp of the abstract sortal, natural number, which shows the hypothesis of empiricism to be wrong.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i)
     A reaction: A nice turning of the tables. In the end only coherence decides these things. You may accept numbers and reject empiricism, and then find you have opened the floodgates for abstracta. Excessive floodgates, or blockages of healthy streams?
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
Treating numbers adjectivally is treating them as quantifiers [Wright,C]
     Full Idea: Treating numbers adjectivally is, in effect, treating the numbers as quantifiers. Frege observes that we can always parse out any apparently adjectival use of a number word in terms of substantival use.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.iii)
     A reaction: The immediate response to this is that any substantival use can equally be expressed adjectivally. If you say 'the number of moons of Jupiter is four', I can reply 'oh, you mean Jupiter has four moons'.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
The Peano Axioms, and infinity of cardinal numbers, are logical consequences of how we explain cardinals [Wright,C]
     Full Idea: The Peano Axioms are logical consequences of a statement constituting the core of an explanation of the notion of cardinal number. The infinity of cardinal numbers emerges as a consequence of the way cardinal number is explained.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xix)
     A reaction: This, along with Idea 13896, nicely summarises the neo-logicist project. I tend to favour a strategy which starts from ordering, rather than identities (1-1), but an attraction is that this approach is closer to counting objects in its basics.
The aim is to follow Frege's strategy to derive the Peano Axioms, but without invoking classes [Wright,C]
     Full Idea: We shall endeavour to see whether it is possible to follow through the strategy adumbrated in 'Grundlagen' for establishing the Peano Axioms without at any stage invoking classes.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xvi)
     A reaction: The key idea of neo-logicism. If you can avoid classes entirely, then set theory paradoxes become irrelevant, and classes aren't logic. Philosophers now try to derive the Peano Axioms from all sorts of things. Wright admits infinity is a problem.
Wright has revived Frege's discredited logicism [Wright,C, by Benardete,JA]
     Full Idea: Crispin Wright has reactivated Frege's logistic program, which for decades just about everybody assumed was a lost cause.
     From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by José A. Benardete - Logic and Ontology 3
     A reaction: [This opens Bernadete's section called "Back to Strong Logicism?"]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Logicism seemed to fail by Russell's paradox, Gödel's theorems, and non-logical axioms [Wright,C]
     Full Idea: Most would cite Russell's paradox, the non-logical character of the axioms which Russell and Whitehead's reconstruction of Frege's enterprise was constrained to employ, and the incompleteness theorems of Gödel, as decisive for logicism's failure.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro)
The standard objections are Russell's Paradox, non-logical axioms, and Gödel's theorems [Wright,C]
     Full Idea: The general view is that Russell's Paradox put paid to Frege's logicist attempt, and Russell's own attempt is vitiated by the non-logical character of his axioms (esp. Infinity), and by the incompleteness theorems of Gödel. But these are bad reasons.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xvi)
     A reaction: Wright's work is the famous modern attempt to reestablish logicism, in the face of these objections.
7. Existence / A. Nature of Existence / 2. Types of Existence
The idea that 'exist' has multiple senses is not coherent [Wright,C]
     Full Idea: I have the gravest doubts whether any coherent account could be given of any multiplicity of senses of 'exist'.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 2.x)
     A reaction: I thoroughly agree with this thought. Do water and wind exist in different senses of 'exist'?
7. Existence / A. Nature of Existence / 3. Being / a. Nature of Being
To grasp being, we must say why something exists, and why there is one world [Jacquette]
     Full Idea: We grasp the concept of being only when we have satisfactorily answered the question why there is something rather than nothing and why there is only one logically contingent actual world.
     From: Dale Jacquette (Ontology [2002], Conclusion)
     A reaction: See Ideas 7688 and 7692 for a glimpse of Jacquette's answer. Personally I don't yet have a full grasp of the concept of being, but I'm sure I'll get there if I only work a bit harder.
7. Existence / A. Nature of Existence / 5. Reason for Existence
Existence is completeness and consistency [Jacquette]
     Full Idea: A combinatorial ontology holds that existence is nothing more or less than completeness and consistency, or what is also called 'maximal consistency'.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: You'll have to read Jacquette to understand this one! The claim is that existence is to be defined in terms of logic (and whatever is required for logic). I take this to be a bit Platonist (rather than conventionalist) about logic.
Being is maximal consistency [Jacquette]
     Full Idea: Being is maximal consistency.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: You'll have to read Ch.2 of Jacquette to see what this is all about, but as it stands it is a lovely slogan, and a wonderful googly/curve ball to propel at Parmenides or Heidegger.
7. Existence / D. Theories of Reality / 1. Ontologies
Ontology is the same as the conceptual foundations of logic [Jacquette]
     Full Idea: The principles of pure philosophical ontology are indistinguishable ... from the conceptual foundations of logic.
     From: Dale Jacquette (Ontology [2002], Pref)
     A reaction: I would take Russell to be an originator of this view. If the young Wittgenstein showed that the foundations of logic are simply conventional (truth tables), this seems to make ontology conventional too, which sounds very odd indeed (to me).
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
Ontology must include the minimum requirements for our semantics [Jacquette]
     Full Idea: The entities included in a theoretical ontology are those minimally required for an adequate philosophical semantics. ...These are the objects that we say exist, to which we are ontologically committed.
     From: Dale Jacquette (Ontology [2002], Pref)
     A reaction: Worded with exquisite care! He does not say that ontology is reducible to semantics (which is a silly idea). We could still be committed, as in a ghost story, to existence of some 'nameless thing'. Things utterly beyond our ken might exist.
7. Existence / D. Theories of Reality / 11. Ontological Commitment / b. Commitment of quantifiers
Singular terms in true sentences must refer to objects; there is no further question about their existence [Wright,C]
     Full Idea: When a class of terms functions as singular terms, and the sentences are true, then those terms genuinely refer. Being singular terms, their reference is to objects. There is no further question whether they really refer, and there are such objects.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.iii)
     A reaction: This seems to be a key sentence, because this whole view is standardly called 'platonic', but it certainly isn't platonism as we know it, Jim. Ontology has become an entirely linguistic matter, but do we then have 'sakes' and 'whereaboutses'?
7. Existence / E. Categories / 3. Proposed Categories
Logic is based either on separate objects and properties, or objects as combinations of properties [Jacquette]
     Full Idea: Logic involves the possibilities of predicating properties of objects in a conceptual scheme wherein either objects and properties are included in altogether separate categories, or objects are reducible to combinations of properties.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: In the first view, he says that objects are just 'logical pegs' for properties. Objects can't be individuated without properties. But combinations of properties would seem to need essences, or else they are too unstable to count as objects.
Reduce states-of-affairs to object-property combinations, and possible worlds to states-of-affairs [Jacquette]
     Full Idea: We can reduce references to states-of-affairs to object-property combinations, and we can reduce logically possible worlds to logically possible states-of-affairs combinations.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: If we further reduce object-property combinations to mere combinations of properties (Idea 7683), then we have reduced our ontology to nothing but properties. Wow. We had better be very clear, then, about what a property is. I'm not.
8. Modes of Existence / B. Properties / 11. Properties as Sets
If classes can't be eliminated, and they are property combinations, then properties (universals) can't be either [Jacquette]
     Full Idea: If classes alone cannot be eliminated from ontology on Quine's terms, and if classes are defined as property combinations, then neither are all properties, universals in the tradition sense, entirely eliminable.
     From: Dale Jacquette (Ontology [2002], Ch. 9)
     A reaction: If classes were totally conventional (and there was no such things as a 'natural' class) then you might admit something to a class without knowing its properties (as 'the thing in the box').
9. Objects / A. Existence of Objects / 1. Physical Objects
An object is a predication subject, distinguished by a distinctive combination of properties [Jacquette]
     Full Idea: To be an object is to be a predication subject, and to be this as opposed to that particular object, whether existent or not, is to have a distinctive combination of properties.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: The last part depends on Leibniz's Law. The difficulty is that two objects may only be distinguishable by being in different places, and location doesn't look like a property. Cf. Idea 5055.
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
Contextually defined abstract terms genuinely refer to objects [Wright,C, by Dummett]
     Full Idea: Wright says we should accord to contextually defined abstract terms a genuine full-blown reference to objects.
     From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Michael Dummett - Frege philosophy of mathematics Ch.18
     A reaction: This is the punch line of Wright's neo-logicist programme. See Idea 9868 for his view of reference. Dummett regards this strong view of contextual definition as 'exorbitant'. Wright's view strikes me as blatantly false.
Numbers, sets and propositions are abstract particulars; properties, qualities and relations are universals [Jacquette]
     Full Idea: Roughly, numbers, sets and propositions are assumed to be abstract particulars, while properties, including qualities and relations, are usually thought to be universals.
     From: Dale Jacquette (Ontology [2002], Ch. 9)
     A reaction: There is an interesting nominalist project of reducing all of these to particulars. Numbers to patterns, sets to their members, propositions to sentences, properties to causal powers, relations to, er, something else.
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
Sortal concepts cannot require that things don't survive their loss, because of phase sortals [Wright,C]
     Full Idea: The claim that no concept counts as sortal if an instance of it can survive its loss, runs foul of so-called phase sortals like 'embryo' and 'chrysalis'.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i)
     A reaction: The point being that those items only fall under that sortal for one phase of their career, and of their identity. I've always thought such claims absurd, and this gives a good reason for my view.
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
The actual world is a consistent combination of states, made of consistent property combinations [Jacquette]
     Full Idea: The actual world is a maximally consistent state-of-affairs combination involving all and only the existent objects, which in turn exist because they are maximally consistent property combinations.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: [This extends Idea 7688]. This seems to invite the standard objections to the coherence theory of truth, such as Ideas 5422 and 4745. Is 'maximal consistency' merely a test for actuality, rather than an account of what actuality is?
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
The actual world is a maximally consistent combination of actual states of affairs [Jacquette]
     Full Idea: The actual world can be defined as a maximally consistent combination of actual states of affairs, or maximally consistent states-of-affairs combination.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: A key part of Jacquette's program of deriving ontological results from the foundations of logic. Is the counterfactual situation of my pen being three centimetres to the left of its current position a "less consistent" situation than the actual one?
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / c. Worlds as propositions
Do proposition-structures not associated with the actual world deserve to be called worlds? [Jacquette]
     Full Idea: Many modal logicians in their philosophical moments have raised doubts about whether structures of propositions not associated with the actual world deserved to be called worlds at all.
     From: Dale Jacquette (Ontology [2002], Ch. 2)
     A reaction: A good question. Consistency is obviously required, but we also need a lot of propositions before we would consider it a 'world'. Very remote but consistent worlds quickly become unimaginable. Does that matter?
We must experience the 'actual' world, which is defined by maximally consistent propositions [Jacquette]
     Full Idea: Conventional modal semantics, in which all logically possible worlds are defined in terms of maximally consistent proposition sets, has no choice except to allow that the actual world is the world we experience in sensation, or that we inhabit.
     From: Dale Jacquette (Ontology [2002], Ch. 9)
     A reaction: Jacquette dislikes this because he is seeking an account of ontology that doesn't, as so often, merely reduce to epistemology (e.g. Berkeley). See Idea 7691 for his preferred account.
15. Nature of Minds / B. Features of Minds / 5. Qualia / c. Explaining qualia
If qualia supervene on intentional states, then intentional states are explanatorily fundamental [Jacquette]
     Full Idea: If qualia supervene on intentional states, then intentionality is also more explanatorily fundamental than qualia.
     From: Dale Jacquette (Ontology [2002], Ch.10)
     A reaction: See Idea 7272 for opposite view. Maybe intentional states are large mental objects of which we are introspectively aware, but which are actually composed of innumerable fine-grained qualia. Intentional states would only explain qualia if they caused them.
17. Mind and Body / E. Mind as Physical / 2. Reduction of Mind
Reduction of intentionality involving nonexistent objects is impossible, as reduction must be to what is actual [Jacquette]
     Full Idea: If intentionality sometimes involves a relation to nonexistent objects, like my dreamed-of visit to a Greek island, then such thoughts cannot be explained physically or causally, because only actual physical entities and events can be mentioned.
     From: Dale Jacquette (Ontology [2002], Ch.10)
     A reaction: Unimpressive. Thoughts of a Greek island will obviously reduce to memories of islands and Greece and travel brochures. Memory clearly retains past events in the present, and hence past events can be part of the material used in reductive accounts.
18. Thought / D. Concepts / 1. Concepts / a. Nature of concepts
A concept is only a sortal if it gives genuine identity [Wright,C]
     Full Idea: Before we can conclude that φ expresses a sortal concept, we need to ensure that 'is the same φ as' generates statements of genuine identity rather than of some other equivalence relation.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i)
'Sortal' concepts show kinds, use indefinite articles, and require grasping identities [Wright,C]
     Full Idea: A concept is 'sortal' if it exemplifies a kind of object. ..In English predication of a sortal concept needs an indefinite article ('an' elm). ..What really constitutes the distinction is that it involves grasping identity for things which fall under it.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i)
     A reaction: This is a key notion, which underlies the claims of 'sortal essentialism' (see David Wiggins).
18. Thought / D. Concepts / 4. Structure of Concepts / b. Analysis of concepts
Entities fall under a sortal concept if they can be used to explain identity statements concerning them [Wright,C]
     Full Idea: 'Tree' is not a sortal concept under which directions fall since we cannot adequately explain the truth-conditions of any identity statement involving a pair of tree-denoting singular terms by appealing to facts to do with parallelism between lines.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xiv)
     A reaction: The idea seems to be that these two fall under 'hedgehog', because that is a respect in which they are identical. I like to notion of explanation as a part of this.
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
If we can establish directions from lines and parallelism, we were already committed to directions [Wright,C]
     Full Idea: The fact that it seems possible to establish a sortal notion of direction by reference to lines and parallelism, discloses tacit commitments to directions in statements about parallelism...There is incoherence in the idea that a line might lack direction.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xviii)
     A reaction: This seems like a slippery slope into a very extravagant platonism about concepts. Are concepts like direction as much a part of the natural world as rivers are? What other undiscovered concepts await us?
19. Language / A. Nature of Meaning / 5. Meaning as Verification
A milder claim is that understanding requires some evidence of that understanding [Wright,C]
     Full Idea: A mild version of the verification principle would say that it makes sense to think of someone as understanding an expression only if he is able, by his use of the expression, to give the best possible evidence that he understands it.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.vii)
     A reaction: That doesn't seem to tell us what understanding actually consists of, and may just be the truism that to demonstrate anything whatsoever will necessarily involve some evidence.
19. Language / B. Reference / 1. Reference theories
If apparent reference can mislead, then so can apparent lack of reference [Wright,C]
     Full Idea: If the appearance of reference can be misleading, why cannot an apparent lack of reference be misleading?
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 2.xi)
     A reaction: A nice simple thought. Analytic philosophy has concerned itself a lot with sentences that seem to refer, but the reference can be analysed away. For me, this takes the question of reference out of the linguistic sphere, which wasn't Wright's plan.
19. Language / C. Assigning Meanings / 3. Predicates
We can accept Frege's idea of object without assuming that predicates have a reference [Wright,C]
     Full Idea: The heart of the problem is Frege's assumption that predicates have Bedeutungen at all; and no reason is at present evident why someone who espouses Frege's notion of object is contrained to make that assumption.
     From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.iv)
     A reaction: This seems like a penetrating objection to Frege's view of reference, and presumably supports the Kripke approach.
19. Language / D. Propositions / 1. Propositions
The extreme views on propositions are Frege's Platonism and Quine's extreme nominalism [Jacquette]
     Full Idea: The extreme ontological alternatives with respect to the metaphysics of propositions are a Fregean Platonism (his "gedanken", 'thoughts'), and a radical nominalism or inscriptionalism, as in Quine, where they are just marks related to stimuli.
     From: Dale Jacquette (Ontology [2002], Ch. 9)
     A reaction: Personally I would want something between the two - that propositions are brain events of a highly abstract kind. I say that introspection reveals pre-linguistic thoughts, which are propositions. A proposition is an intentional state.
20. Action / C. Motives for Action / 4. Responsibility for Actions
Criminal responsibility can be fully assigned to each member of a group [Walzer]
     Full Idea: It is a feature of criminal responsibility that it can be distributed without being divided. We can, that is, blame more than one person for a particular act without splitting up the blame we assign.
     From: Michael Walzer (Just and Unjust Wars [1977], 19)
     A reaction: How far can this extend? To a large violent mob? To an entire nation? In court the responsibility is usually adjusted in the sentencing, rather than in the initial verdict.
20. Action / C. Motives for Action / 5. Action Dilemmas / b. Double Effect
Double Effect needs a double intention - to achieve the good, and minimise the evil [Walzer]
     Full Idea: Double effect is defensible, I want to argue, only when the two outcomes are the product of a double intention - that 'good' be achieved, and that the foreseeable evil be reduced as far as possible.
     From: Michael Walzer (Just and Unjust Wars [1977], 09)
     A reaction: A good proposal, I think. We have to accept evil side effects sometimes, but it is immoral to pursue some good 'whatever the cost'.
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / d. Ethical theory
Deep ethical theory is very controversial, but we have to live with higher ethical practice [Walzer]
     Full Idea: The substructure of the ethical world is a matter of deep and unending controversy, Meanwhile, however, we are living in the superstructure.
     From: Michael Walzer (Just and Unjust Wars [1977], Pref)
     A reaction: This may be the best approach to ethics. Nearly all applied ethics takes the common sense consensus on values for granted. Personally I think that is because the substructure is the obvious success and failure of human functioning.
25. Social Practice / C. Rights / 1. Basis of Rights
If whole states possess rights, there can be social relations between states [Walzer]
     Full Idea: If states possess rights more or less as individuals do, then it is possible to imagine a society among them more or less like the individuals.
     From: Michael Walzer (Just and Unjust Wars [1977], 04)
     A reaction: The state's rights must derive from the people. Plots of land don't have rights. In some states the people are in conflict. It can't just be the government which represents the rights of the state.
25. Social Practice / E. Policies / 1. War / a. Just wars
States can rightly pre-empt real and serious threats [Walzer]
     Full Idea: States can use force in the face of threats of war, if there is a serious risk to territory or independence. They are then forced to fight, and are the victims of aggression.
     From: Michael Walzer (Just and Unjust Wars [1977], 05)
     A reaction: [compressed] He uses this to justify Israeli pre-emptive strikes against Palestinians. I don't think his confident assertion of this principle is justified. It is open to massive abuse. There are, though, clearly situations where he is right.
Just wars are self-defence, or a rightful intercession in another's troubles [Walzer]
     Full Idea: Just wars may not be self-defence, if they are to help an independence struggle, or it is to save another country being invaded, or to prevent enslavement or massacre.
     From: Michael Walzer (Just and Unjust Wars [1977], 06)
     A reaction: [summary] Modern wars support some examples of these, but also suggest that without a long-term plan, or an understanding of the country they are entering, such intercessions may worsen the situation.
The aim of reprisals is to enforce the rules of war [Walzer]
     Full Idea: The purpose of reprisals is not to win the war or prevent defeat, but simply to enforce the rules [of war].
     From: Michael Walzer (Just and Unjust Wars [1977], 13)
     A reaction: That may be wishful thinking, since reprisals are often vastly more ruthless than the original offence, and there is often injustice in the nature of the reprisals, since they cannot be precise.
Reprisal is defensible, as an alternative to war [Walzer]
     Full Idea: Reprisal is the first resort of force. It is an alternative to war, and that description is an important argument in its favour.
     From: Michael Walzer (Just and Unjust Wars [1977], 13)
     A reaction: Enduring wrongs with dignity might be another alternative. Successful reprisals may be acceptable, but how do you assess their prospects?
With nuclear weapons we have a permanent supreme emergency (which is unstable) [Walzer]
     Full Idea: With nuclear weapons, supreme emergency has become a permanent condition. …[283] But supreme emergency is never a stable position.
     From: Michael Walzer (Just and Unjust Wars [1977], 17)
     A reaction: The obvious instability of balanced mutual threat is a nuclear state which finds itself losing a war.
States need not endure attacks passively, and successful reprisals are legitimate [Walzer]
     Full Idea: Whenever there is some substantial chance of success, reprisals are the legitimate resort of a victim state; for no state can be required passively to endure attacks upon its citizens.
     From: Michael Walzer (Just and Unjust Wars [1977], 13)
     A reaction: My concern is whether the reprisals have any direct connection to the attacks. They killed some of ours, so we will kill some of theirs is immoral. E.g. bombing Tripoli as reprisal for crashing the Lockerbie plane.
Even non-violent intrusive acts between states count as aggression, if they justify resistance [Walzer]
     Full Idea: Every violation of an independent state is called aggression, which fails to differentiate between a seizure or imposition, and an actual conquest. …But what they have in common is that all aggressive acts justify forceful resistance.
     From: Michael Walzer (Just and Unjust Wars [1977], 04)
     A reaction: [compressed] Walzer concedes that this makes 'aggression' rather imprecise, and small acts can be used as an excuse for desired violent resistance. Each entrant in August 1914 seems to have had a slightly different motive.
The only good reason for fighting is in defence of rights [Walzer]
     Full Idea: The defence of rights is a reason for fighting. I want now to stress again, and finally, that it is the only reason.
     From: Michael Walzer (Just and Unjust Wars [1977], 04)
     A reaction: Walzer states at the beginning, without discussion, that his moral assumptions are based on the notion of rights. This is tricky because rights are assigned by some people to other people, and claims of rights can be challenged.
Nuclear bombs are not for normal war; they undermine the 'just war', with a new morality [Walzer]
     Full Idea: Nuclear weapons are not designed for war at all. …They explode the idea of a just war. They are the first technological innovations that are simply not encompassable within the familiar moral world.
     From: Michael Walzer (Just and Unjust Wars [1977], 17)
     A reaction: A nuclear war can hardly lead to normal victory, if it destroys the thing you are trying to conquer. It is like bringing a machine gun to a boxing match.
25. Social Practice / E. Policies / 1. War / b. Justice in war
For moral reasons, a just war must be a limited war [Walzer]
     Full Idea: Just wars are limited wars; there are moral reasons for the statesmen and soldiers who fight them to be prudent and realistic.
     From: Michael Walzer (Just and Unjust Wars [1977], 07)
     A reaction: This is rather profound, I think. Watch closely the behaviour of the good guys when they are winning the war. In general, to know someone's moral principles, the best indicator is how they behave when they have power.
Napoleon said 'I don't care about the deaths of a million men' [Walzer]
     Full Idea: Napoleon said 'Soldiers are made to be killed. …I do not care a fig for the lives of a million men'.
     From: Michael Walzer (Just and Unjust Wars [1977], 08)
     A reaction: [Two separate remarks attributed to Napoleon] He apparently often said things like this this later in his career. It strikes me as despicable, and anyone who still tries to present Napoleon as admirable should be ashamed.
Jus ad bellum and Jus in bello are independent; unjust wars can be fought in a just way [Walzer]
     Full Idea: Justice of war [ad bellum] and justice in war [in bello] are logically independent. It is perfectly possible for a just war to be fought unjustly, and for an unjust war to be fought in strict accordance with the rules.
     From: Michael Walzer (Just and Unjust Wars [1977], 02)
     A reaction: The perfect decorum of an unjust firing squad might even make the crime worse. There is something chilling about an evil army conducting itself perfectly within the ethics of warfare. Better than the other thing, though. McMahan disagrees.
25. Social Practice / E. Policies / 1. War / c. Combatants
The duties and moral status of loyal and obedient soldiers is the same in defence and aggression [Walzer]
     Full Idea: The duties of individual soldiers …are precisely the same in wars of aggression and wars of defence. …The moral status of soldiers on both sides is very much the same; they are led to fight by their loyalty and their lawful obedience.
     From: Michael Walzer (Just and Unjust Wars [1977], 08)
     A reaction: He excludes war crimes. This is the thesis which Jeff McMahan objects to. It would be very odd to think that mafiosi and the legitimate police were morally equal, because the former are loyal. We should all try hard to avoid supporting unjust causes.
We can't blame soldiers for anything they do which clearly promotes victory [Walzer]
     Full Idea: It would be difficult to condemn soldiers for anything they did in the course of a battle or a war that they honestly believed, and had good reason to believe, was necessary, or important, or simply useful in determining the outcome.
     From: Michael Walzer (Just and Unjust Wars [1977], 08)
     A reaction: We can't blame unjust aggressors if their own lives are at stake, but what about in a surprise attack on the first day of the war (such as Pearl Harbour)? Or if they massacre the enemy with safe and overwhelming superiority?
Rejecting Combatant Equality allows just soldiers to be harsher, even to the extreme [Walzer]
     Full Idea: Objections to combatant equality appeal to a sliding scale of 'the more justice, the more right'. …It allows the justice of one's cause to make a difference in the way one fights. …The extreme says soldiers fightly justly can do anything that is useful.
     From: Michael Walzer (Just and Unjust Wars [1977], 14)
     A reaction: This slippery slope fear seems to be Walzer's main argument in favour of the moral equality of combatants. See Jeff McMahan for the opposing view.
Even aggressor soldiers are not criminals, so they have equal rights with their opponents [Walzer]
     Full Idea: Soldiers fighting for an aggressor state are not themselves criminals: hence their war rights are the same as those of their opponents.
     From: Michael Walzer (Just and Unjust Wars [1977], 08)
     A reaction: Walzer's main support for this is that opposing armies never regard one another as intrinsically criminal. It seems inevitable, though, that even the invaders themselves see that they are a bit more criminal than the defenders.
Kidnapped sailors and volunteers have different obligations to the passengers [Walzer]
     Full Idea: Soldiers may stand to civilians like the crew of a liner to its passengers, for whom they must risk their lives. …But would they be so bound if the sailors had been kidnapped?
     From: Michael Walzer (Just and Unjust Wars [1977], 19)
     A reaction: The point, I assume, is that a conscripted army does not have the same obligations as volunteers. I can't imagine that principle being accepted in an army which is a mixture of the two.
25. Social Practice / E. Policies / 1. War / d. Non-combatants
Soldiers will only protect civilians if they feel safe from them [Walzer]
     Full Idea: Soldiers must feel safe among civilians if civilians are ever to be safe from soldiers.
     From: Michael Walzer (Just and Unjust Wars [1977], 11)
     A reaction: This is the great dilemma of any resistance movement. It is very easy for the soldiers to abuse their power, even if they do feel safe. Then what?
What matters in war is unacceptable targets, not unacceptable weapons [Walzer]
     Full Idea: The crucial distinction in the theory and practice of war is not between prohibited and acceptable weapons but between prohibited and acceptable targets.
     From: Michael Walzer (Just and Unjust Wars [1977], 17)
     A reaction: Walzer presents this idea as arising out of discussions about nuclear deterrence. Gas attacks were accepted in WW1 trenches, but modern gas attacks on civilians are a crime. Are nuclear attacks on strictly military targets OK? E.g a fleet.
If the oppressor is cruel, nonviolence is either surrender, or a mere gesture [Walzer]
     Full Idea: When one cannot count on the moral code of the oppressor, nonviolence is either a disguised form of surrender or a minimalist way of upholding communal values after a military defeat.
     From: Michael Walzer (Just and Unjust Wars [1977], Afterword)
     A reaction: The point is that ruthless conquerors may just kill the nonviolent, so it would achieve nothing. Nonviolence is only a plausible strategy in a fairly civilised world. Hard to disagree.
25. Social Practice / E. Policies / 1. War / e. Peace
We can only lead war towards peace if we firmly enforce the rules of war [Walzer]
     Full Idea: We must begin by insisting upon the rules of war and by holding soldiers rigidly to the norms they set. The restraint of war is the beginning of peace.
     From: Michael Walzer (Just and Unjust Wars [1977], Afterword)
     A reaction: Last sentence of his book. Some cultures have a much greater tradition of ruthless cruelty than others, it seems. Most war ethics seems to concern how the good guys should respond to the bad guys (since the latter hardly care).