Combining Philosophers

All the ideas for H.Putnam/P.Oppenheim, Nathan Salmon and Jonathan Schaffer

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90 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Modern Quinean metaphysics is about what exists, but Aristotelian metaphysics asks about grounding [Schaffer,J]
     Full Idea: On the now dominant Quinean view, metaphysics is about what there is (such as properties, meanings and numbers). I will argue for the revival of a more traditional Aristotelian view, on which metaphysics is about what grounds what.
     From: Jonathan Schaffer (On What Grounds What [2009], Intro)
     A reaction: I find that an enormously helpful distinction, and support the Aristotelian view. Schaffer's general line is that what exists is fairly uncontroversial and dull, but the interesting truths about the world emerge when we grasp its structure.
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
If you tore the metaphysics out of philosophy, the whole enterprise would collapse [Schaffer,J]
     Full Idea: Traditional metaphysics is so tightly woven into the fabric of philosophy that it cannot be torn out without the whole tapestry unravelling.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.3)
     A reaction: I often wonder why the opponents of metaphysics still continue to do philosophy. I don't see how you address questions of ethics, or philosophy of mathematics (etc) without coming up against highly general and abstract over-questions.
1. Philosophy / F. Analytic Philosophy / 3. Analysis of Preconditions
Analysis aims at secure necessary and sufficient conditions [Schaffer,J]
     Full Idea: An analysis is an attempt at providing finite, non-circular, and intuitively adequate necessary and sufficient conditions.
     From: Jonathan Schaffer (Causation and Laws of Nature [2008], 3)
     A reaction: Specifying the 'conditions' for something doesn't seem to quite add up to telling you what the thing is. A trivial side-effect might qualify as a sufficient condition for something, if it always happens.
2. Reason / B. Laws of Thought / 6. Ockham's Razor
We should not multiply basic entities, but we can have as many derivative entities as we like [Schaffer,J]
     Full Idea: Occam's Razor should only be understood to concern substances: do not multiply basic entities without necessity. There is no problem with the multiplication of derivative entities - they are an 'ontological free lunch'.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1)
     A reaction: The phrase 'ontological free lunch' comes from Armstrong. This is probably what Occam meant. A few extra specks of dust, or even a few more numbers (thank you, Cantor!) don't seem to challenge the principle.
2. Reason / D. Definition / 11. Ostensive Definition
Ostensive definitions needn't involve pointing, but must refer to something specific [Salmon,N]
     Full Idea: So-called ostensive definitions need not literally involve ostension, e.g. pointing, but they must involve genuine reference of some sort (in this case reference to a sample of water).
     From: Nathan Salmon (Reference and Essence (1st edn) [1981], 4.11.2)
2. Reason / F. Fallacies / 1. Fallacy
'Reification' occurs if we mistake a concept for a thing [Schaffer,J]
     Full Idea: 'Reification' occurs when a mere concept is mistaken for a thing. We seem generally prone to this sort of error.
     From: Jonathan Schaffer (Causation and Laws of Nature [2008], 3.1)
     A reaction: Personally I think we should face up to the fact that this is the only way we can think about generalised or abstract entities, and stop thinking of it as an 'error'. We have evolved to think well about objects, so we translate everything that way.
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
T adds □p→p for reflexivity, and is ideal for modeling lawhood [Schaffer,J]
     Full Idea: System T is a normal modal system augmented with the reflexivity-generating axiom □p→p, and is, I think, the best modal logic for modeling lawhood.
     From: Jonathan Schaffer (Causation and Laws of Nature [2008], n46)
     A reaction: Schaffer shows in the article why transitivity would not be appropriate for lawhood.
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
S4, and therefore S5, are invalid for metaphysical modality [Salmon,N, by Williamson]
     Full Idea: Salmon argues that S4 and therefore S5 are invalid for metaphysical modality.
     From: report of Nathan Salmon (Reference and Essence (1st edn) [1981], 238-40) by Timothy Williamson - Modal Logic within Counterfactual Logic 4
     A reaction: [He gives references for Salmon, and for his own reply] Salmon's view seems to be opposed my most modern logicians (such as Ian Rumfitt).
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 / E. Structures of Logic / 1. Logical Form
Logical form can't dictate metaphysics, as it may propose an undesirable property [Schaffer,J]
     Full Idea: Logical form should not have the last word in metaphysics, since it might predicate a property that we have theoretical reason to reject.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1.3.1)
     A reaction: These kind of warnings need to be sounded all the time, to prevent logicians and language experts from pitching their tents in the middle of metaphysics. They are welcome guests only,
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
If 'there are red roses' implies 'there are roses', then 'there are prime numbers' implies 'there are numbers' [Schaffer,J]
     Full Idea: We can automatically infer 'there are roses' from 'there are red roses' (with no shift in the meaning of 'roses'). Likewise one can automatically infer 'there are numbers' from 'there are prime numbers'.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1)
     A reaction: He similarly observes that the atheist's 'God is a fictional character' implies 'there are fictional characters'. Schaffer is not committing to a strong platonism with his claim - merely that the existence of numbers is hardly worth disputing.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
If a notion is ontologically basic, it should be needed in our best attempt at science [Schaffer,J]
     Full Idea: Science represents our best systematic understanding of the world, and if a certain notion proves unneeded in our best attempt at that, this provides strong evidence that what this notion concerns is not ontologically basic.
     From: Jonathan Schaffer (Causation and Laws of Nature [2008], 3.2)
     A reaction: But is the objective of science to find out what is 'ontologically basic'? If scientists can't get a purchase on a question, they have no interest in it. What are electrons made of?
7. Existence / C. Structure of Existence / 1. Grounding / a. Nature of grounding
Grounding is unanalysable and primitive, and is the basic structuring concept in metaphysics [Schaffer,J]
     Full Idea: Grounding should be taken as primitive, as per the neo-Aristotelian approach. Grounding is an unanalyzable but needed notion - it is the primitive structuring conception of metaphysics.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.2)
     A reaction: [he cites K.Fine 1991] I find that this simple claim clarifies the discussions of Kit Fine, where you are not always quite sure what the game is. I agree fully with it. It makes metaphysics interesting, where cataloguing entities is boring.
As causation links across time, grounding links the world across levels [Schaffer,J]
     Full Idea: Grounding is something like metaphysical causation. Just as causation links the world across time, grounding links the world across levels. Grounding connects the more fundamental to the less fundamental, and thereby backs a certain form of explanation.
     From: Jonathan Schaffer (Grounding, Transitivity and Contrastivity [2012], Intro)
     A reaction: Obviously you need 'levels' for this, which we should take to be structural levels.
If ground is transitive and irreflexive, it has a strict partial ordering, giving structure [Schaffer,J]
     Full Idea: By treating grounding as transitive (and irreflexive), one generates a strict partial ordering that induces metaphysical structure.
     From: Jonathan Schaffer (Grounding, Transitivity and Contrastivity [2012], Intro)
     A reaction: Schaffer's paper goes on to attach the claim that grounding is transitive, but I didn't find his examples very convincing.
7. Existence / C. Structure of Existence / 2. Reduction
Three types of reduction: Theoretical (of terms), Definitional (of concepts), Ontological (of reality) [Schaffer,J]
     Full Idea: Theoretical reduction concerns terms found in a theory; Definitional reduction concerns concepts found in the mind; Ontological reduction is independent of how we conceptualize entities, or theorize about them, and is about reality.
     From: Jonathan Schaffer (Causation and Laws of Nature [2008], 1)
     A reaction: An Aristotelian definition refers to reality, rather than to our words or concepts.
7. Existence / C. Structure of Existence / 5. Supervenience / a. Nature of supervenience
Supervenience is just modal correlation [Schaffer,J]
     Full Idea: Supervenience is mere modal correlation.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.2)
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
The cosmos is the only fundamental entity, from which all else exists by abstraction [Schaffer,J]
     Full Idea: My preferred view is that there is only one fundamental entity - the whole concrete cosmos - from which all else exists by abstraction.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1)
     A reaction: This looks to me like weak anti-realism - that there are no natural 'joints' in nature - but I don't think Schaffer intends that. I take the joints to be fundamentals, which necessitates that the cosmos has parts. His 'abstraction' is clearly a process.
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
There is only one fact - the True [Schaffer,J]
     Full Idea: It can be argued that if all facts are logically equivalent, then there is only one fact - the True.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1.1)
     A reaction: [he cites Davidson's 'Causal Relations', who cites Frege] This is the sort of bizarre stuff you end up with if you start from formal logic and work out to the world, instead of vice versa.
7. Existence / D. Theories of Reality / 10. Vagueness / g. Degrees of vagueness
It can't be indeterminate whether x and y are identical; if x,y is indeterminate, then it isn't x,x [Salmon,N]
     Full Idea: Insofar as identity seems vague, it is provably mistaken. If it is vague whether x and y are identical (as in the Ship of Theseus), then x,y is definitely not the same as x,x, since the first pair is indeterminate and the second pair isn't.
     From: Nathan Salmon (Reference and Essence: seven appendices [2005], App I)
     A reaction: [compressed; Gareth Evans 1978 made a similar point] This strikes me as begging the question in the Ship case, since we are shoehorning the new ship into either the slot for x or the slot for y, but that was what we couldn’t decide. No rough identity?
7. Existence / E. Categories / 4. Category Realism
Maybe categories are just the different ways that things depend on basic substances [Schaffer,J]
     Full Idea: Maybe the categories are determined by the different grounding relations, ..so that categories just are the ways things depend on substances. ...Categories are places in the dependence ordering.
     From: Jonathan Schaffer (On What Grounds What [2009], 1.3)
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
Tropes are the same as events [Schaffer,J]
     Full Idea: Tropes can be identified with events.
     From: Jonathan Schaffer (Causation and Laws of Nature [2008], n17)
     A reaction: This is presumably on the view of events, associated with Kim, as instantiations of properties. This idea is a new angle on tropes and events which had never occurred to me.
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Individuation aims to count entities, by saying when there is one [Schaffer,J]
     Full Idea: Individuation principles are attempts to describe how to count entities in a given domain, by saying when there is one.
     From: Jonathan Schaffer (Causation and Laws of Nature [2008], 3)
     A reaction: At last, someone tells me what they mean by 'individuation'! So it is just saying what your units are prior to counting, followed (presumably) by successful counting. It seems to aim more at kinds than at particulars.
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
No sortal could ever exactly pin down which set of particles count as this 'cup' [Schaffer,J]
     Full Idea: Many decent candidates could the referent of this 'cup', differing over whether outlying particles are parts. No further sortal I could invoke will be selective enough to rule out all but one referent for it.
     From: Jonathan Schaffer (Deflationary Metaontology of Thomasson [2009], 3.1 n8)
     A reaction: I never had much faith in sortals for establishing individual identity, so this point comes as no surprise. The implication is strongly realist - that the cup has an identity which is permanently beyond our capacity to specify it.
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
There exist heaps with no integral unity, so we should accept arbitrary composites in the same way [Schaffer,J]
     Full Idea: I am happy to accept universal composition, on the grounds that there are heaps, piles etc with no integral unity, and that arbitrary composites are no less unified than heaps.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1 n11)
     A reaction: The metaphysical focus is then placed on what constitutes 'integral unity', which is precisely the question which most interested Aristotle. Clearly if there is nothing more to an entity than its components, scattering them isn't destruction.
The notion of 'grounding' can explain integrated wholes in a way that mere aggregates can't [Schaffer,J]
     Full Idea: The notion of grounding my capture a crucial mereological distinction (missing from classical mereology) between an integrated whole with genuine unity, and a mere aggregate. x is an integrated whole if it grounds its proper parts.
     From: Jonathan Schaffer (On What Grounds What [2009], 3.1)
     A reaction: That gives a nice theoretical notion, but if you remove each of the proper parts, does x remain? Is it a bare particular? I take it that it will have to be an abstract principle, the one Aristotle was aiming at with his notion of 'form'. Schaffer agrees.
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
Essentialism says some properties must be possessed, if a thing is to exist [Salmon,N]
     Full Idea: The metaphysical doctrine of essentialism says that certain properties of things are properties that those things could not fail to have, except by not existing.
     From: Nathan Salmon (Reference and Essence (1st edn) [1981], 3.8.2)
     A reaction: A bad account of essentialism, and a long way from Aristotle. It arises from the logicians' tendency to fix objects entirely in terms of a 'flat' list of predicates (called 'properties'!), which ignore structure, constitution, history etc.
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 / 6. Identity between Objects
Identities can be true despite indeterminate reference, if true under all interpretations [Schaffer,J]
     Full Idea: There can be determinately true identity claims despite indeterminate reference of the terms flanking the identity sign; these will be identity claims true under all admissible interpretations of the flanking terms.
     From: Jonathan Schaffer (Deflationary Metaontology of Thomasson [2009], 3.1)
     A reaction: In informal contexts there might be problems with the notion of what is 'admissible'. Is 'my least favourite physical object' admissible?
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
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 / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
Only ideal conceivability could indicate what is possible [Schaffer,J]
     Full Idea: The only plausible link from conceivability to possibility is via ideal conceivability.
     From: Jonathan Schaffer (Causation and Laws of Nature [2008], n22)
     A reaction: [He cites Chalmers 2002] I'm not sure what 'via' could mean here. Since I don't know any other way than attempted conceivability for assessing a possibility, I am a bit baffled by this idea.
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
Belief in impossible worlds may require dialetheism [Schaffer,J]
     Full Idea: One motivation for dialetheism is the view that there are impossible worlds.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.3)
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'.
11. Knowledge Aims / B. Certain Knowledge / 2. Common Sense Certainty
'Moorean certainties' are more credible than any sceptical argument [Schaffer,J]
     Full Idea: A 'Moorean certainty' is when something is more credible than any philosopher's argument to the contrary.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1)
     A reaction: The reference is to G.E. Moore's famous claim that the existence of his hand is more certain than standard sceptical arguments. It sounds empiricist, but they might be parallel rational truths, of basic logic or arithmetic.
14. Science / D. Explanation / 2. Types of Explanation / b. Contrastive explanations
Explaining 'Adam ate the apple' depends on emphasis, and thus implies a contrast [Schaffer,J]
     Full Idea: Explaining why ADAM ate the apple is a different matter from explaining why he ATE the apple, and from why he ate THE APPLE. ...In my view the best explanations incorporate ....contrastive information.
     From: Jonathan Schaffer (Grounding, Transitivity and Contrastivity [2012], 4.3.1)
     A reaction: But why are the contrasts Eve, or throwing it, or a pear? It occurs to me that this is wrong! The contrast is with anything else which could have gone in subject, verb or object position. It is a matter of categories, not of contrasts.
14. Science / D. Explanation / 2. Types of Explanation / j. Explanations by reduction
Six reduction levels: groups, lives, cells, molecules, atoms, particles [Putnam/Oppenheim, by Watson]
     Full Idea: There are six 'reductive levels' in science: social groups, (multicellular) living things, cells, molecules, atoms, and elementary particles.
     From: report of H.Putnam/P.Oppenheim (Unity of Science as a Working Hypothesis [1958]) by Peter Watson - Convergence 10 'Intro'
     A reaction: I have the impression that fields are seen as more fundamental that elementary particles. What is the status of the 'laws' that are supposed to govern these things? What is the status of space and time within this picture?
19. Language / B. Reference / 1. Reference theories
Frege's 'sense' solves four tricky puzzles [Salmon,N]
     Full Idea: Reference via sense solves Frege's four puzzles, of the informativeness of identity statements, the failure of substitutivity in attitude contexts, of negative existentials, and the truth-value of statements using nondenoting singular terms.
     From: Nathan Salmon (Reference and Essence (1st edn) [1981], 1.1.1)
     A reaction: These must then be compared with Kripke's three puzzles about referring via sense, and the whole debate is then spread before us.
19. Language / B. Reference / 3. Direct Reference / a. Direct reference
The perfect case of direct reference is a variable which has been assigned a value [Salmon,N]
     Full Idea: The paradigm of a nondescriptional, directly referential, singular term is an individual variable. …The denotation of a variable… is semantically determined directly by the assignment of values.
     From: Nathan Salmon (Reference and Essence (1st edn) [1981], 1.1.2)
     A reaction: This cuts both ways. Maybe we are muddling ordinary reference with the simplicities of logical assignments, or maybe we make logical assignments because that is the natural way our linguistic thinking works.
Kripke and Putnam made false claims that direct reference implies essentialism [Salmon,N]
     Full Idea: Kripke and Putnam made unsubstantiated claims, indeed false claims, to the effect that the theory of direct reference has nontrivial essentialist import.
     From: Nathan Salmon (Reference and Essence: seven appendices [2005], Pref to Exp Ed)
     A reaction: Kripke made very few claims, and is probably innocent of the charge. Most people agree with Salmon that you can't derive metaphysics from a theory of reference.
26. Natural Theory / A. Speculations on Nature / 1. Nature
I take what is fundamental to be the whole spatiotemporal manifold and its fields [Schaffer,J]
     Full Idea: I myself would prefer to speak of what is fundamental in terms of the whole spatiotemporal manifold and the fields that permeate it, with parts counting as derivative of the whole.
     From: Jonathan Schaffer (Grounding, Transitivity and Contrastivity [2012], 4.1.1)
     A reaction: Not quite the Parmenidean One, since it has parts, but a nice try at updating the great man. Note the reference to 'fields', suggesting that this view is grounded in the physics rather than metaphysics. How many fields has it got?
26. Natural Theory / B. Natural Kinds / 5. Reference to Natural Kinds
Nothing in the direct theory of reference blocks anti-essentialism; water structure might have been different [Salmon,N]
     Full Idea: There seems to be nothing in the theory of direct reference to block the anti-essentialist assertion that the substance water might have been the very same entity and yet have had a different chemical structure.
     From: Nathan Salmon (Reference and Essence (1st edn) [1981], 6.23.1)
     A reaction: Indeed, water could be continuously changing its inner structure, while retaining the surface appearance that gets baptised as 'water'. We make the reasonable empirical assumption, though, that structure-change implies surface-change.
26. Natural Theory / C. Causation / 1. Causation
In causation there are three problems of relata, and three metaphysical problems [Schaffer,J]
     Full Idea: The questions about causation concern their relata (in space-time, how fine-grained, how many?) and the metaphysics (distinguish causal sequences from others, the direction of causation, selecting causes among pre-conditions?).
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], Intro)
     A reaction: A very nice map (which has got me thinking about restructuring this database). I can't think of a better way to do philosophy than this (let's hear it for analysis - but the greatest role models for the approach are Aristotle and Aquinas).
Causation may not be transitive; the last event may follow from the first, but not be caused by it [Schaffer,J]
     Full Idea: It is not clear whether causation is transitive. For example, if a boulder roll's towards a hiker's head, causing the hiker to duck, which causes the hiker to survive, it does not seem that the rolling boulder causes the survival of the hiker.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1.2)
     A reaction: Maybe survival is not an event or an effect. How many times have I survived in my life? We could, though, say that the hiker strained a muscle as he or she ducked. But then it is unclear whether the boulder caused the muscle-strain.
There are at least ten theories about causal connections [Schaffer,J]
     Full Idea: Theories of causal connection are: nomological subsumption, statistical correlation, counterfactual dependence, agential manipulability, contiguous change, energy flow, physical processes, property transference, primitivism and eliminativism.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1.3.1)
     A reaction: Schaffer reduces these to probability and process. I prefer the latter. The first two are wrong, the third right but superficial, the fourth wrong, the fifth, sixth and seventh on the right lines, the eighth wrong, the ninth tempting, and the last wrong.
Nowadays causation is usually understood in terms of equations and variable ranges [Schaffer,J]
     Full Idea: The leading treatments of causation work within 'structural equation models', with events represented via variables each of which is allotted a range of permitted values, which constitute a 'contrast space'.
     From: Jonathan Schaffer (Grounding, Transitivity and Contrastivity [2012], 4.3.1)
     A reaction: Like Woodward's idea that causation is a graph, this seems to be a matter of plotting or formalising correlations between activities, which is a very Humean approach to causation.
26. Natural Theory / C. Causation / 4. Naturalised causation
Causation transcends nature, because absences can cause things [Schaffer,J]
     Full Idea: The main argument for causation being transcendent (rather than being immanent in nature) is that absences can be involved in causal relations. Thus a rock-climber is caused to survive by not falling.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1.1)
     A reaction: I don't like that. The obvious strategy is to redescribe the events. Even being hit with a brick could be described as an 'absence of brick-prevention'. So not being hit by a brick can be described as 'presence of brick prevention'.
Causation may not be a process, if a crucial part of the process is 'disconnected' [Schaffer,J]
     Full Idea: One problem case for the process view of causation is 'disconnection'. If a brick breaks a window by being fired from a catapult, a latch is released which was preventing the catapult from firing, so the 'process' is just internal to the catapult.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.1)
     A reaction: Schaffer says the normal reply is to deny that the catch-releasing is genuinely causal. I would have thought we should go more fine-grained, and identify linked components of the causal process.
A causal process needs to be connected to the effect in the right way [Schaffer,J]
     Full Idea: A problem case for the process view of causation is 'misconnection'. A process may be connected to an effect, without being causal, as when someone watches an act of vandalism in dismay.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.1)
     A reaction: This is a better objection to the process view than Idea 10377. If I push a window with increasing force until it breaks, the process is continuous, but it suddenly becomes a cause.
Causation can't be a process, because a process needs causation as a primitive [Schaffer,J]
     Full Idea: It might be that if causation is said to be a process, then a process is nothing more than a causal sequence, so that causation is primitive.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: This again is tempting (as well as the primitivist view of probabilistic causation). If one tries to define a process as mere chronology, then the causal and accidental are indistinguishable. I take the label 'primitive' to be just our failure.
26. Natural Theory / C. Causation / 5. Direction of causation
At least four rivals have challenged the view that causal direction is time direction [Schaffer,J]
     Full Idea: The traditional view that the direction of causation is the direction of time has been challenged, by the direction of forking, by overdetermination, by independence, and by manipulation, which all seem to be one-directional features.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1.3.1)
     A reaction: Personally I incline to the view that time is prior, and fixes the direction of causation. I'm not sure that 'backward causation' can be stated coherently, even if it is metaphysically or naturally possible.
Causal order must be temporal, or else causes could be blocked, and time couldn't be explained [Schaffer,J]
     Full Idea: Reasons for causal order being temporal order are that otherwise the effect might occur but the cause then get prevented, ..and that they must be the same, because the temporal order can only be analysed in terms of the causal order.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.2)
     A reaction: If one took both time and causation as primitive, then the second argument would be void. The first argument, though, sounds pretty overwhelming to me.
Causal order is not temporal, because of time travel, and simultanous, joint or backward causes [Schaffer,J]
     Full Idea: Reasons for denying that causal order is temporal order are that time travel seems possible, that cause and effect can be simultaneous, because joint effects have temporal order without causal connection, and because backward causation may exist.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.2)
     A reaction: The possibility of time travel and backward causation can clearly be doubted, and certainly can't be grounds for one's whole metaphysics. The other two need careful analysis, but I think they can be answered. Causation is temporal.
26. Natural Theory / C. Causation / 6. Causation as primitive
Causation is primitive; it is too intractable and central to be reduced; all explanations require it [Schaffer,J]
     Full Idea: Primitivism arises from our failure to reduce causation, but also from causation being too central to reduce. The probability and process accounts are said to be inevitably circular, as they cannot be understood without reference to causation.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: This is very tempting. The primitive view, though, must deal with the direction problem, which may suggest that time is even more primitive. Can we have a hierarchy of primitiveness? To be alive is to be causal.
If causation is just observables, or part of common sense, or vacuous, it can't be primitive [Schaffer,J]
     Full Idea: The three main objections to causation being primitive are that causation can't be anything more than what we observe, or that such a primitive is too spooky to be acceptable, or that primitivism leads to elimination of causation.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: [summarised] I don't like the first (Humean) view. I suspect that anything which we finally decide has to be primitive (time, for example) is going to be left looking 'spooky', and I suspect that eliminativism is just Humeanism in disguise.
26. Natural Theory / C. Causation / 7. Eliminating causation
The notion of causation allows understanding of science, without appearing in equations [Schaffer,J]
     Full Idea: The concepts of 'event', 'law', 'cause' and 'explanation' are nomic concepts which serve to allow a systematic understanding of science; they do not themselves appear in the equations.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: This is a criticism of Russell's attempt to eliminate causation from science. It shows that there has to be something we can call 'metascience', which is the province of philosophers, since scientists don't have much interest in it.
Causation is utterly essential for numerous philosophical explanations [Schaffer,J]
     Full Idea: Causation can't be eliminated if it is needed to explain persistence, explanation, disposition, perception, warrant, action, responsibility, mental functional role, conceptual content, and reference. It's elimination would be catastrophic.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: [compressed list] I think I am going to vote for the view that causation is one of the primitives in the metaphysics of nature, so I have to agree with this. Most of the listed items, though, are controversial, so eliminativists are not defeated.
26. Natural Theory / C. Causation / 8. Particular Causation / a. Observation of causation
If two different causes are possible in one set of circumstances, causation is primitive [Schaffer,J]
     Full Idea: Causation seems to be primitive if the same laws and patterns of events might embody three different possible causes, as when two magicians cast the same successful spell, each with a 50% chance of success, and who was successful is unclear.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: I'm cautious when the examples involve magic. It implies that the process that leads to the result will be impossible to observe, but if magic never really happens, then the patterns of events will always be different.
If causation is primitive, it can be experienced in ourselves, or inferred as best explanation [Schaffer,J]
     Full Idea: The view that causation is primitive can be defended against Humean critics by saying that causation can be directly observed in the will or our bodies, or that it can be inferred as the best explanation.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: I like both views, and have just converted myself to the primitivist view of causation! I can't know the essence of a tree, because I am not a tree, but I can know the essence of causation. The Greek fascination with explaining movement is linked.
26. Natural Theory / C. Causation / 8. Particular Causation / b. Causal relata
Events are fairly course-grained (just saying 'hello'), unlike facts (like saying 'hello' loudly) [Schaffer,J]
     Full Idea: Events are relatively coarse-grained, unlike facts; so the event of John's saying 'hello' seems to be the same event as John's saying 'hello' loudly, while they seem to be different facts.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1)
     A reaction: The example seems good support for facts, since saying 'hello' loudly could have quite different effects from just saying 'hello'. I also incline temperamentally towards a fine-grained account, because it is more reductivist.
Causal relata are events - or facts, features, tropes, states, situations or aspects [Schaffer,J]
     Full Idea: The standard view make causal relata events (Davidson, Kim, Lewis), but there is considerable support for facts (Bennett, Mellor), and occasional support for features (Dretske), tropes (Campbell), states of affairs (Armstrong), and situations and aspects.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1)
     A reaction: An event is presumed to be concrete, while a fact is more abstract (a proposition, perhaps). I'm always drawn to 'processes' (because they are good for discussing the mind), so an event, as a sort of natural process, looks good.
One may defend three or four causal relata, as in 'c causes e rather than e*' [Schaffer,J]
     Full Idea: The view that there are two causal relata is widely assumed but seldom defended. But the account based on 'effectual difference' says the form is 'c causes e rather than e*'. One might defend four relata, in 'c rather than c* causes e rather than e*'.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1)
     A reaction: [compressed] This doesn't sound very plausible to me. How do you decide which is e*? If I lob a brick into the crowd, it hits Jim rather than - who?
If causal relata must be in nature and fine-grained, neither facts nor events will do [Schaffer,J]
     Full Idea: Theorists who reject both events and facts as causal relata do so because the relata must be immanent in nature, and thus not facts, but also fine-grained and thus not events.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 1.2)
     A reaction: Kim, however, offers a fine-grained account of events (as triples), and Bennett individuates them even more finely (as propositions), so events might be saved. Descriptions can be very fine-grained.
The relata of causation (such as events) need properties as explanation, which need causation! [Schaffer,J]
     Full Idea: The primitivist about causation might say that the notion of an event (or other relata) cannot be understood without reference to causation, because properties themselves are individuated by their causal role.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: Having enthusiastically embraced the causal view of properties (see Shoemaker and Ellis), I suddenly realise that I seem required to embrace primitivism about causation, which I hadn't anticipated! I've no immediate problem with that.
26. Natural Theory / C. Causation / 8. Particular Causation / d. Selecting the cause
Our selection of 'the' cause is very predictable, so must have a basis [Schaffer,J]
     Full Idea: The main argument against saying that there is no basis for selecting the one cause of an event is that our selections are too predictable to be without a basis.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.3)
     A reaction: The problem is that we CAN, if we wish, whimsically pick out any pre-condition of an event for discussion (e.g. the railways before WW1). I would say that sensitivity to nature leads us to a moderately correct selection of 'the' cause.
Selecting 'the' cause must have a basis; there is no causation without such a selection [Schaffer,J]
     Full Idea: Another argument against the view that there is no basis for selecting 'the' cause is that we have no concept of causation without such a selection.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.3)
     A reaction: Good. Otherwise we could only state the conditions preceding an event, and then every event that occurred at any given moment in a region would have the same cause. How can 'the' cause be necessary, and yet capricious?
26. Natural Theory / C. Causation / 8. Particular Causation / e. Probabilistic causation
The actual cause may make an event less likely than a possible more effective cause [Schaffer,J]
     Full Idea: If Pam threw the brick that broke the window, then Bob (who refrained) might be a more reliable vandal, so that Pam's throw might have made the shattering less likely, so probability-raising is not necessary for causation.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1)
     A reaction: That objection looks pretty conclusive to me. I take the probabilistic view to be a non-starter.
All four probability versions of causation may need causation to be primitive [Schaffer,J]
     Full Idea: All four probability versions of causation may need causation to be primitive: nomological - to distinguish laws from generalizations; statistical - to decide background; counterfactual - decide background; agent intervention - to understand intervention.
     From: Jonathan Schaffer (The Metaphysics of Causation [2007], 2.1.2)
     A reaction: I don't need much convincing that the probabilistic view is wrong. To just accept causation as primitive seems an awful defeat for philosophy. We should be able to characterise it, even if we cannot know its essence.