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All the ideas for 'Issues of Pragmaticism', 'Logical Properties' and 'The Logic of What Might Have Been'

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68 ideas

2. Reason / D. Definition / 1. Definitions
Definitions identify two concepts, so they presuppose identity [McGinn]
     Full Idea: Any definition must presuppose the notion of identity precisely because a definition affirms the identity of two concepts.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: McGinn is arguing that identity is fundamental to thought, and this seems persuasive. It may be, though, that while identities are inescapable, definitions are impossible.
2. Reason / F. Fallacies / 2. Infinite Regress
Regresses are only vicious in the context of an explanation [McGinn]
     Full Idea: Regresses are only vicious in the context of some explanatory aim, not in themselves.
     From: Colin McGinn (Logical Properties [2000], Ch.2 n11)
     A reaction: A nice point. It is not quite clear how 'pure' reason could ever be vicious, or charming, or sycophantic. The problem about a vicious regress is precisely that it fails to explain anything. Now benign regresses are something else… (see Idea 2523)
3. Truth / A. Truth Problems / 4. Uses of Truth
Truth is a method of deducing facts from propositions [McGinn]
     Full Idea: Truth is essentially a method of deducing facts from propositions.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: Very persuasive. McGinn is offering a disquotational account of truth, but in a robust form. Of course, deduction normally takes the form of moving infallibly from one truth to another, but that model of deduction won't fit this particular proposal.
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
'Snow does not fall' corresponds to snow does fall [McGinn]
     Full Idea: We can say that the proposition that snow does not fall from the sky corresponds to the fact that snow does fall from the sky - in the sense that there is a mapping from fact to proposition.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: A very nice difficulty for the correspondence theory. It becomes essential to say how the two things correspond before it can offer any sort of account of the truth-relation.
The idea of truth is built into the idea of correspondence [McGinn]
     Full Idea: The correspondence theory has an air of triviality, and hence undeniability, but this is because it implicitly builds the idea of truth into the notion of correspondence.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: If this is accepted, it is a really fatal objection to the theory. Russell tried to use the idea of 'congruency' between beliefs and reality, but that may be open to the same objection. McGinn is claiming that truth is essentially indefinable.
3. Truth / D. Coherence Truth / 2. Coherence Truth Critique
The coherence theory of truth implies idealism, because facts are just coherent beliefs [McGinn]
     Full Idea: If 'snow falls from the sky' is true iff it coheres with other beliefs, this is a form of idealism; snow could surely fall from sky even if there were no beliefs in the world to cohere with each other.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: The coherence theory of truth strikes me as yet another blunder involving a confusion of ontology and epistemology. Of course, idealism may be true, but I have yet to hear a good reason why I should abandon commonsense realism.
3. Truth / H. Deflationary Truth / 3. Minimalist Truth
Truth is the property of propositions that makes it possible to deduce facts [McGinn]
     Full Idea: Truth is a property of a proposition from which one can deduce the fact stated by the proposition.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: This is McGinn's explanation of the disquotational account of truth ('p' is true iff p). The redundancy theorist would reply that you can deduce p from 'p' without mentioning truth, but it remains to ask why this deduction is possible.
Without the disquotation device for truth, you could never form beliefs from others' testimony [McGinn]
     Full Idea: Imagine being in a community which had no concept of truth; ..you cannot disquote on p and hence form beliefs about the world as a result of testimony, since you lack the device of disquotation that is the essence of truth.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: Whether his theory is right or not, the observation that testimony is the really crucial area where we must have a notion of truth is very good. How about 'truth is what turns propositions into beliefs'?
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / b. Terminology of ML
A world is 'accessible' to another iff the first is possible according to the second [Salmon,N]
     Full Idea: A world w' is accessible to a consistent world w if and only if w' is possible in w. Being 'inaccessible to' or 'possible relative to' a consistent world is simply being possible according to that world, nothing more and nothing less.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], IV)
     A reaction: More illuminating than just saying that w can 'see' w'. Accessibility is internal to worIds. It gives some connection to why we spend time examining modal logic. There is no more important metaphysical notion than what is possible according to actuality.
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / d. System T
For metaphysics, T may be the only correct system of modal logic [Salmon,N]
     Full Idea: Insofar as modal logic is concerned exclusively with the logic of metaphysical modality, ..T may well be the one and only (strongest) correct system of (first-order) propositional logic.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], Intro)
     A reaction: This contrasts sharply with the orthodox view, that S5 (or at the very least S4) is the correct system for metaphysics.
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / f. System B
System B has not been justified as fallacy-free for reasoning on what might have been [Salmon,N]
     Full Idea: Even the conventionally accepted system B, which is weaker than S5 and independent of S4, has not been adequately justified as a fallacy-free system of reasoning about what might have been.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], Intro)
In B it seems logically possible to have both p true and p is necessarily possibly false [Salmon,N]
     Full Idea: The characteristic of B has the form φ⊃□◊φ. ...Even if these axioms are necessarily true, it seems logically possible for p to be true while the proposition that p is necessarily possible is at the same time false.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], Intro)
System B implies that possibly-being-realized is an essential property of the world [Salmon,N]
     Full Idea: Friends of B modal logic commit themselves to the loaded claim that it is logically true that the property of possibly being realized (or being a way things might have been) is an essential property of the world.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], V)
     A reaction: I think this 'loaded' formulation captures quite nicely the dispositional view I favour, that the possibilities of the actual world are built into the actual world, and define its nature just as much as the 'categorial' facts do.
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
What is necessary is not always necessarily necessary, so S4 is fallacious [Salmon,N]
     Full Idea: We can say of a wooden table that it would have been possible for it to have originated from some different matter, even though it is not actually possible. So what is necessary fails to be necessarily necessary, and S4 modal logic is fallacious.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], I)
     A reaction: [compressed]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
S5 modal logic ignores accessibility altogether [Salmon,N]
     Full Idea: When we ignore accessibility altogether, we have finally zeroed in on S5 modal logic.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], IV)
S5 believers say that-things-might-have-been-that-way is essential to ways things might have been [Salmon,N]
     Full Idea: Believers in S5 as a correct system of propositional reasoning about what might have been must claim that it is an essential property of any way things might have been that things might have been that way.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], V)
     A reaction: Salmon is working in a view where you are probably safe to substitute 'necessary' for 'essential' without loss of meaning.
The unsatisfactory counterpart-theory allows the retention of S5 [Salmon,N]
     Full Idea: Counterpart-theoretic modal semantics allows for the retention of S5 modal propositional logic, at a considerable cost.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], V n18)
     A reaction: See the other ideas in this paper by Salmon for his general attack on S5 as the appropriate system for metaphysical necessity. He favours the very modest System T.
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
Metaphysical (alethic) modal logic concerns simple necessity and possibility (not physical, epistemic..) [Salmon,N]
     Full Idea: Metaphysical modal logic concerns metaphysical (or alethic) necessity and metaphysical (alethic) possibility, or necessity and possibility tout court - as opposed to such other types of modality as physical necessity, epistemic necessity etc.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], Intro n2)
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
In 'x is F and x is G' we must assume the identity of x in the two statements [McGinn]
     Full Idea: If we say 'for some x, x is F and x is G' we are making tacit appeal to the idea of identity in using 'x' twice here: it has to be the same object that is both F and G.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: This may well be broadened to any utterances whatsoever. The only remaining question is to speculate about whether it is possible to think without identities. The Hopi presumably gave identity to processes rather objects. How does God think?
Both non-contradiction and excluded middle need identity in their formulation [McGinn]
     Full Idea: To formulate the law of non-contradiction ('nothing can be both F and non-F') and the law of excluded middle ('everything is either F or it is not-F'), we need the concept of identity (in 'nothing' and 'everything').
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: Two good examples in McGinn's argument that identity is basic to all thinking. But the argument also works to say that necessity is basic (since both laws claim it) and properties are basic. Let's just declare everything 'basic', and we can all go home.
Identity is unitary, indefinable, fundamental and a genuine relation [McGinn]
     Full Idea: I have endorsed four main theses about identity: it is unitary, it is indefinable, it is fundamental, and it is a genuine relation
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: That it is fundamental to our thinking seems certain (but to all possible thought?). That it is a relation looks worth questioning. One might challenge unitary by comparing the identity of numbers, values, electrons and continents. I can't define it.
5. Theory of Logic / G. Quantification / 1. Quantification
The quantifier is overrated as an analytical tool [McGinn]
     Full Idea: The quantifier has been overrated as a tool of logical and linguistic analysis.
     From: Colin McGinn (Logical Properties [2000], Pref)
     A reaction: I find this proposal quite thrilling. Twentieth century analytical philosophy has been in thrall to logic, giving the upper hand in philosophical discussion to the logicians, who are often not very good at philosophy.
Existential quantifiers just express the quantity of things, leaving existence to the predicate 'exists' [McGinn]
     Full Idea: What the existential quantifier does is indicate the quantity of things in question - it says that some are; it is left up to the predicate 'exists' to express existence.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: This seems right. The whole quantification business seems like a conjuring trick to conceal the embarrassingly indefinable and 'metaphysical' notion of 'existence'. Cf Idea 7697.
5. Theory of Logic / G. Quantification / 3. Objectual Quantification
'Partial quantifier' would be a better name than 'existential quantifier', as no existence would be implied [McGinn]
     Full Idea: We would do much better to call 'some' the 'partial quantifier' (rather than the 'existential quantifier'), on analogy with the universal quantifier - as neither of them logically implies existence.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: Like McGinn's other suggestions in this chapter, this strikes me as a potentially huge clarification in linguistic analysis. I wait with interest to see whether the philosophical logicians take it up. I bet they don't.
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
We need an Intentional Quantifier ("some of the things we talk about.."), so existence goes into the proposition [McGinn]
     Full Idea: We could introduce an 'intentional quantifier' (Ix) which means 'some of the things we talk about..'; we could then say 'some of the things we talk about are F and exist' (Ix, x is F and x exists).
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: This immediately strikes me as a promising contribution to the analytical toolkit. McGinn is supporting his view that existence is a predicate, and so belongs inside the proposition, not outside.
7. Existence / A. Nature of Existence / 1. Nature of Existence
Existence is a primary quality, non-existence a secondary quality [McGinn]
     Full Idea: Existence is like a primary quality; non-existence is like a secondary quality.
     From: Colin McGinn (Logical Properties [2000], Ch.2 n29)
     A reaction: Since McGinn thinks existence really is a property, and hence, presumably, a predicate, I don't quite see why he uses the word "like". A nicely pithy and thought-provoking remark.
7. Existence / A. Nature of Existence / 6. Criterion for Existence
Existence can't be analysed as instantiating a property, as instantiation requires existence [McGinn]
     Full Idea: Paraphrasing existence statements into statements about the instantiation of a property does not establish that existence is not a predicate, since the notion of instantiation must be taken to have existence built into it.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: Thank you, Colin McGinn! This now strikes me as so obvious that it is astonishing that for the whole of the twentieth century no one seems to have said it. For a century philosophers had swept the ontological dirt under the mat.
We can't analyse the sentence 'something exists' in terms of instantiated properties [McGinn]
     Full Idea: The problems of the orthodox view are made vivid by analysis of the sentence 'something exists'; this is meaningful and true, but what property are we saying is instantiated here?
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: A very nice point. McGinn claims that existence is a property, a very generalised one. Personally I don't think anyone is even remotely clear what a property is, so the whole discussion is a bit premature. Must properties have causal powers?
7. Existence / D. Theories of Reality / 3. Reality
If causal power is the test for reality, that will exclude necessities and possibilities [McGinn]
     Full Idea: Whether my body weight is necessary or contingent makes no difference at all to my causal powers, so modality is epiphenomenal; if you took causal potential as a test of reality you would have to declare modes unreal.
     From: Colin McGinn (Logical Properties [2000], Ch.4)
     A reaction: We could try analysing modality into causal terms, as Lewis proposes with quantification across worlds, or as Quine proposes by reduction to natural regularities. I am not sure what it would mean to declare that modes are 'real'.
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
Facts are object-plus-extension, or property-plus-set-of-properties, or object-plus-property [McGinn]
     Full Idea: A fact may be an object and an extension (Quine's view), or a property and a set of properties, or an object and a property; the view I favour is the third one, which seems the most natural.
     From: Colin McGinn (Logical Properties [2000], Ch.3)
     A reaction: Personally I tend to use the word 'fact' in a realist and non-linguistic way. There must be innumerable inexpressible facts, such as the single pattern made by all the particles of the universe. McGinn seems to be talking of 'atomic facts'. See Idea 6111.
9. Objects / D. Essence of Objects / 15. Against Essentialism
Any property is attached to anything in some possible world, so I am a radical anti-essentialist [Salmon,N]
     Full Idea: By admitting possible worlds of unlimited variation and recombination, I simply abandon true metaphysical essentialism. By my lights, any property is attached to anything in some possible world or other. I am a closet radical anti-essentialist.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], II)
     A reaction: Salmon includes impossible worlds within his scheme of understanding. It strikes me that this is metaphysical system which tells us nothing about how things are: it is sort of 'logical idealist'. Later he talks of 'we essentialists'.
9. Objects / F. Identity among Objects / 1. Concept of Identity
Identity propositions are not always tautological, and have a key epistemic role [McGinn]
     Full Idea: Identity propositions are not always analytic or a priori (as Frege long ago taught us) so there is nothing trivial about such propositions; the claim of redundancy ignores the epistemic role that the concept of identity plays.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: He is referring to Frege's Morning Star/Evening Star distinction (Idea 4972). Wittgenstein wanted to eliminate our basic metaphysics by relabelling it as analytic or tautological, but his project failed. Long live metaphysics!
9. Objects / F. Identity among Objects / 2. Defining Identity
Identity is as basic as any concept could ever be [McGinn]
     Full Idea: Identity has a universality and basicness that is hard to overstate; concepts don't get more basic than this - or more indispensable.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: I agree with this. It seems to me to follow that the natural numbers are just as basic, because they are entailed by the separateness of the identities of things. And the whole of mathematics is the science of the patterns within these numbers.
9. Objects / F. Identity among Objects / 4. Type Identity
Type-identity is close similarity in qualities [McGinn]
     Full Idea: Two things are said to be type-identical when they are similar enough to be declared qualitatively identical.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: A simple point which brings out the fact that type-identity is unlikely to be any sort of true identity (unless there is absolutely no different at all between two electrons, say).
Qualitative identity is really numerical identity of properties [McGinn]
     Full Idea: A statement of so-called qualitative identity is really a statement of numerical identity (that is, identity tout court) about the properties of the objects in question - assuming that there are genuine universals.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: We might agree that two cars are type-identical, even though (under the microscope) we decided that none of their properties were absolutely identical.
Qualitative identity can be analysed into numerical identity of the type involved [McGinn]
     Full Idea: We can analyse qualitative identity in terms of numerical identity, by saying that x and y are type-identical if there is a single type T that x and y both are, i.e. they both exemplify the same type.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: This just seems to shift the problem onto the words 'are' and 'exemplify'. This takes us back to the problem of things 'partaking' of Plato's Forms. Better to say that qualitative identity isn't identity - it is resemblance (see Idea 6045).
It is best to drop types of identity, and speak of 'identity' or 'resemblance' [McGinn]
     Full Idea: It would be better to drop talk of 'numerical' and 'qualitative' identity altogether, speaking instead simply of identity and resemblance.
     From: Colin McGinn (Logical Properties [2000], Ch.1 n4)
     A reaction: This is the kind of beautifully simple proposal I pay analytical philosophers to come up with. I will attempt in future to talk either of 'identity' (which is strict), or 'resemblance' (which comes in degrees).
9. Objects / F. Identity among Objects / 5. Self-Identity
Existence is a property of all objects, but less universal than self-identity, which covers even conceivable objects [McGinn]
     Full Idea: Existence is a property universal to all objects that exist, somewhat like self-identity, but less universal, because self-identity holds of all conceivable objects, not merely those that happen to exist.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: This is a splendidly defiant response to the Kantian slogan that 'existence is not a predicate', and I find McGinn persuasive. I can still not find anyone to explain to me exactly what a property is, so I will reserve judgement.
Sherlock Holmes does not exist, but he is self-identical [McGinn]
     Full Idea: Sherlock Holmes does not exist, but he is self-identical (he is certainly not indentical to Dr Watson).
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: Most significant. Identity does not entail existence; identity is necessary for existence (I think) but not sufficient. But the notion of existence might be prior to the notion of identity, and the creation of Holmes be parasitic on real existence.
9. Objects / F. Identity among Objects / 6. Identity between Objects
All identity is necessary, though identity statements can be contingently true [McGinn]
     Full Idea: All identity is necessary, although there can be contingently true identity statements - those that contain non-rigid designators.
     From: Colin McGinn (Logical Properties [2000], Ch.1 n5)
     A reaction: A nice case of the need to keep epistemology and ontology separate. An example might be 'The Prime Minister wears a wig', where 'Prime Minister' may not be a rigid designator. 'Winston wears a wig' will be necessary, if true (which it wasn't).
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Leibniz's Law says 'x = y iff for all P, Px iff Py' [McGinn]
     Full Idea: Leibniz's Law says 'x = y iff for all P, Px iff Py'.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: That is, two things are the same if when we say that one thing (x) has a property (P), then we are saying that the other thing (y) also has the property. A usefully concise statement of the Law.
Leibniz's Law is so fundamental that it almost defines the concept of identity [McGinn]
     Full Idea: Leibniz's Law, which a defender of relative identity might opt to reject, is so fundamental to the notion of identity that rejecting it amounts to changing the subject.
     From: Colin McGinn (Logical Properties [2000], Ch.1 n8)
     A reaction: The Law here is the 'indiscernibility of identicals'. I agree with McGinn, and anyone who loses their grip on this notion of identity strikes me as losing all grip on reality, and threatening their own sanity (well, call it their 'philosophical sanity').
Leibniz's Law presupposes the notion of property identity [McGinn]
     Full Idea: Leibniz's Law presupposes the notion of property identity.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: A very important observation, because it leads to recognition of the way in which basic concepts and categories of thought interconnect. Which is more metaphysically basic, identity or properties? It is not easy to say…
10. Modality / A. Necessity / 3. Types of Necessity
Logical possibility contains metaphysical possibility, which contains nomological possibility [Salmon,N]
     Full Idea: Just as nomological possibility is a special kind of metaphysical possibility, so metaphysical possibility is a special kind of logical possibility.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], III)
     A reaction: This is the standard view of how the three types of necessity are nested. He gives a possible counterexample in footnote 7.
10. Modality / A. Necessity / 5. Metaphysical Necessity
In the S5 account, nested modalities may be unseen, but they are still there [Salmon,N]
     Full Idea: The S5 theorist's miscontrual of English (in the meaning of 'possibly possible') makes nested modality unseen, but it does not make nested modality vanish. Inaccessible worlds are still worlds.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], IV)
Metaphysical necessity is said to be unrestricted necessity, true in every world whatsoever [Salmon,N]
     Full Idea: It is held that it is the hallmark of metaphysical necessity is that it is completely unrestricted, the limiting case of restricted necessity, with no restrictions whatever. A proposition is necessary only if it is true in absolutely every world whatever.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], II)
     A reaction: This is the standard picture which leads to the claim that S5 modal logic is appropriate for metaphysical necessity, because there are no restrictions on accessibility. Salmon raises objections to this conventional view.
Bizarre identities are logically but not metaphysically possible, so metaphysical modality is restricted [Salmon,N]
     Full Idea: Though there is a way things logically could be according to which I am a credit card account, there is no way things metaphysically might be according to which I am a credit card account. This illustrates the restricted nature of metaphysical modality.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], III)
     A reaction: His drift is that metaphyical modality is restricted, but expressing it in S5 modal logic (where all worlds see one another) makes it unrestricted, so S5 logic is wrong for metaphysics. I'm impressed by his arguments.
Without impossible worlds, the unrestricted modality that is metaphysical has S5 logic [Salmon,N]
     Full Idea: If one confines one's sights to genuinely possible worlds, disavowing the impossible worlds, then metaphysical modality emerges as the limiting case - the 'unrestricted' modality that takes account of 'every' world - and S5 emerges as its proper logic.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], IV)
     A reaction: He observes that this makes metaphysical modality 'restricted' simply because you have restricted what 'all worlds' means. Could there be non-maximal worlds? Are logical and metaphysical modality coextensive? I think I like the S5 view.
Metaphysical necessity is NOT truth in all (unrestricted) worlds; necessity comes first, and is restricted [Salmon,N]
     Full Idea: A mythology gave us the idea that metaphysical necessity is truth in every world whatsoever, without restriction. But the notion of metaphysical modality comes first, and, like every notion of modality, it is restricted.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], IV)
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessity is free of constraints, and may accommodate all of S5 logic [Salmon,N]
     Full Idea: With its freedom from the constraint of metaphysical possibility, logical necessity may be construed as accommodating all the axioms and rules of S5.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], III)
     A reaction: He goes on to raise problems for this simple thought. The big question: what are the limits of what is actually possible? Compare: what are the limits of what is imaginable? what are the limits of what is meaningfully sayable?
10. Modality / A. Necessity / 7. Natural Necessity
Nomological necessity is expressed with intransitive relations in modal semantics [Salmon,N]
     Full Idea: Intransitive relations are introduced into modal semantics for the purposes of interpreting various 'real' or restricted types of modalities, such as nomological necessity.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], II)
     A reaction: The point here is that the (so-called) 'laws of nature' are held to change from world to world, so necessity in one could peter out in some more remote world, rather than being carried over everywhere. A very Humean view of such things.
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modality is not objects or properties, but the type of binding of objects to properties [McGinn]
     Full Idea: Modality has a special ontological category: it consists neither in objects (possible worlds theory) nor in properties (predicate modifier view), but items I have called 'modes', ..which can be hard/soft/rigid/pliable binding of objects to properties.
     From: Colin McGinn (Logical Properties [2000], Ch.4)
     A reaction: As so often, McGinn is very persuasive. Essentially he is proposing that modality is adverbial. He associates the middle view with David Wiggins.
Necessity and possibility are not just necessity and possibility according to the actual world [Salmon,N]
     Full Idea: The real meanings of the simple modal terms 'necessary' and 'possible' are not the same as the concepts of actual necessity and actual possibility, necessity and possibility according to the actual world.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], IV)
     A reaction: If you were an 'actualist' (who denies everything except the actual world) then you are unlikely to agree with this. In unrestricted possible worlds, being true in one world makes it possible in all worlds. So actual necessity is possible everywhere.
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
If 'possible' is explained as quantification across worlds, there must be possible worlds [McGinn]
     Full Idea: If we replace modal words like 'possible' with quantification across worlds, clearly the notion of 'world' must exclude impossible worlds, otherwise 'possibly p' will be true if 'p' holds in an impossible world.
     From: Colin McGinn (Logical Properties [2000], Ch.4)
     A reaction: The point here, of course, is that the question is being begged of what 'possible' and 'impossible' actually mean.
Impossible worlds are also ways for things to be [Salmon,N]
     Full Idea: Total ways things cannot be are also 'worlds', or maximal ways for things to be. They are impossible worlds.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], I)
     A reaction: This unorthodox view doesn't sound too plausible to me. To think of a circular square as a 'way things could be' sounds pretty empty, and mere playing with words. The number 7 could be the Emperor of China?
Denial of impossible worlds involves two different confusions [Salmon,N]
     Full Idea: Every argument I am aware of against impossible worlds confuses ways for things to be with ways things might have been, or worse, confuses ways things cannot be with ways for things to be that cannot exist - or worse yet, commits both errors.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], III)
     A reaction: He is claiming that 'ways for things to be' allows impossible worlds, whereas 'ways things might have been' appears not to. (I think! Read the paragraph yourself!)
Without impossible worlds, how things might have been is the only way for things to be [Salmon,N]
     Full Idea: If one ignores impossible worlds, then ways things might have been are the only ways for things to be that are left.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], IV)
     A reaction: Impossible worlds are included in 'ways for things to be', but excluded from 'ways things might have been'. I struggle with a circle being square as a 'way for circles to be'. I suppose being the greatest philosopher is a way for me to be.
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds rely on what might have been, so they can' be used to define or analyse modality [Salmon,N]
     Full Idea: On my conception, the notions of metaphysical necessity and possibility are not defined or analyzed in terms of the apparatus of possible worlds. The order of analysis is just the reverse: possible worlds rely on the notion of what might have been.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], IV)
     A reaction: This view seems to be becoming the new orthodoxy, and I certainly agree with it. I have no idea how you can begin to talk about possible worlds if you don't already have some idea of what 'possible' means.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Possible worlds are maximal abstract ways that things might have been [Salmon,N]
     Full Idea: I conceive of possible worlds as certain sorts of maximal abstract entities according to which certain things (facts, states of affairs) obtain and certain other things do not obtain. They are total ways things might have been.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], I)
Possible worlds just have to be 'maximal', but they don't have to be consistent [Salmon,N]
     Full Idea: As far as I can tell, worlds need not be logically consistent. The only restriction on worlds is that they must be (in some sense) 'maximal' ways for things to be.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], I)
     A reaction: The normal idea of a maximal model is that it must contain either p or ¬p, and not both, so I don't think I understand this thought, but I pass it on.
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / c. Worlds as propositions
You can't define worlds as sets of propositions, and then define propositions using worlds [Salmon,N]
     Full Idea: It is not a good idea to think of possible worlds as sets of propositions, and at the same time to think of propositions as sets of possible worlds.
     From: Nathan Salmon (The Logic of What Might Have Been [1989], I n3)
     A reaction: Salmon favours thinking of worlds as sets of propositions, and hence rejects the account of propositions as sets of worlds. He favours the 'Russellian' view of propositions, which seem to me to be the same as 'facts'.
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
Necessity and possibility are big threats to the empiricist view of knowledge [McGinn]
     Full Idea: It is clear that modality is a prima-facie threat to the usual kind of naturalistic-causal-empiricist theory of knowledge.
     From: Colin McGinn (Logical Properties [2000], Ch.4)
     A reaction: This is why modern empiricists spend of a lot of energy on trying to analyse counterfactuals and laws of nature. Rationalists are much happier to assert necessities a priori, but then they often don't have much basis for their claims.
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Scepticism about reality is possible because existence isn't part of appearances [McGinn]
     Full Idea: Scepticism about the external world is possible because you can never build existence into the appearances, so it must always be inferred or assumed.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: When McGinn's claim that existence is a very universal property begins to produce interesting observations like this, I think we should take it very seriously.
19. Language / A. Nature of Meaning / 1. Meaning
The meaning or purport of a symbol is all the rational conduct it would lead to [Peirce]
     Full Idea: The entire intellectual purport of any symbol consists in the total of all modes of rational conduct which, conditionally upon all the possible different circumstances and desires, would ensue upon the acceptance of the symbol.
     From: Charles Sanders Peirce (Issues of Pragmaticism [1905], EP ii.246), quoted by Danielle Macbeth - Pragmatism and Objective Truth p.169 n1
     A reaction: Macbeth says pragmatism is founded on this theory of meaning, rather than on a theory of truth. I don't see why the causes of a symbol shouldn't be as much a part of its meaning as the consequences are.
19. Language / C. Assigning Meanings / 5. Fregean Semantics
Semantics should not be based on set-membership, but on instantiation of properties in objects [McGinn]
     Full Idea: Semantics should not employ the relationship of set-membership between objects and extensions, but rather the relation of instantiation between objects and properties.
     From: Colin McGinn (Logical Properties [2000], Ch.3)
     A reaction: At least this means that philosophers won't be required to read fat books on set theory, but they will have to think very carefully about 'instantiation'. A good start is the ideas on 'Partaking' of Platonic Forms in this database (in 'Universals').
19. Language / C. Assigning Meanings / 7. Extensional Semantics
Clearly predicates have extensions (applicable objects), but are the extensions part of their meaning? [McGinn]
     Full Idea: We are taught that predicates have extensions - the class of objects of which the predicate is true - which seems hard to deny; but a stronger claim is also made - that extensions are semantically relevant features of predicates.
     From: Colin McGinn (Logical Properties [2000], Ch.3)
     A reaction: He cites Quine as a spokesman for this view. McGinn is going on to challenge it, by defending universals. It seems to fit in with other externalist theories of concepts and meanings, none of which seems very appealing to me.
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
If Satan is the most imperfect conceivable being, he must have non-existence [McGinn]
     Full Idea: Satan cannot exist because he is the most imperfect conceivable being, and existence is one of the perfections.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: The logic of this seems right to me. Presumably the theologians would hastily deny this as a definition of Satan; he must have some positive qualities (like power) in order to enact his supreme moral imperfections. NIce, though.
I think the fault of the Ontological Argument is taking the original idea to be well-defined [McGinn]
     Full Idea: My own suspicion about the Ontological Argument is that the fault lies in taking notions like 'the most perfect, impressive and powerful being conceivable' to be well-defined.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: I'm tempted to put it more strongly: the single greatest challenge for the theist with intellectual integrity is to give a clear and coherent definition of God. There must be no internal contradictions, and it must be within the bounds of possibility.