Combining Philosophers

All the ideas for Lynch,MP/Glasgow,JM, Alan Sidelle and Leon Horsten

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76 ideas

1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Philosophy is the most general intellectual discipline [Horsten]
     Full Idea: Philosophy is the most general intellectual discipline.
     From: Leon Horsten (The Tarskian Turn [2011], 05.1)
     A reaction: Very simple, but exactly how I see the subject. It is continuous with the sciences, and tries to give an account of nature, but operating at an extreme level of generality. It must respect the findings of science, but offer bold interpretations.
1. Philosophy / E. Nature of Metaphysics / 6. Metaphysics as Conceptual
Metaphysics is clarifying how we speak and think (and possibly improving it) [Sidelle]
     Full Idea: Metaphysics, for the conventionalist, is not a matter of trying to see deeply into the structure of mind-independent reality, but of trying to clarify the way we actually speak and think, and perhaps negotiating ways of doing this to our best advantage.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.1)
     A reaction: Note that he is still allowing space for 'revisionary' as well as for 'descriptive' metaphysics. I can't wholly accept this, as I really do think we can have some deep insights into reality, but Sidelle is articulating a large part of the truth.
2. Reason / D. Definition / 2. Aims of Definition
A definition should allow the defined term to be eliminated [Horsten]
     Full Idea: A definition allows a defined term to be eliminated in every context in which it appears.
     From: Leon Horsten (The Tarskian Turn [2011], 04.2)
     A reaction: To do that, a definition had better be incredibly comprehensive, so that no nice nuance of the original term is thrown out.
2. Reason / D. Definition / 8. Impredicative Definition
Predicative definitions only refer to entities outside the defined collection [Horsten]
     Full Idea: Definitions are called 'predicative', and are considered sound, if they only refer to entities which exist independently from the defined collection.
     From: Leon Horsten (Philosophy of Mathematics [2007], §2.4)
2. Reason / E. Argument / 7. Thought Experiments
We seem to base necessities on thought experiments and imagination [Sidelle]
     Full Idea: Judgments of necessity seem always to be based on thought experiments and appeals to what we can imagine.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.1)
     A reaction: That is, the denial of this thing seems inconceivable. I would say that they are also based on coherence. The idea that we can think without imagination is nonsense.
3. Truth / A. Truth Problems / 1. Truth
Semantic theories of truth seek models; axiomatic (syntactic) theories seek logical principles [Horsten]
     Full Idea: There are semantical theories of truth, concerned with models for languages containing the truth predicate, and axiomatic (or syntactic) theories, interested in basic logical principles governing the concept of truth.
     From: Leon Horsten (The Tarskian Turn [2011], 01.1)
     A reaction: This is the map of contemporary debates, which seem now to have given up talking about 'correspondence', 'coherence' etc.
Truth is a property, because the truth predicate has an extension [Horsten]
     Full Idea: I take truth to be a property because the truth predicate has an extension - the collection of all true sentences - and this collection does not (unlike the 'extension' of 'exists') consist of everything, or even of all sentences.
     From: Leon Horsten (The Tarskian Turn [2011], 01.1)
     A reaction: He concedes that it may be an 'uninteresting' property. My problem is always that I am unconvinced that truth is tied to sentences. I can make perfect sense of animal thoughts being right or wrong. Extension of mental propositions?
3. Truth / A. Truth Problems / 2. Defining Truth
Truth has no 'nature', but we should try to describe its behaviour in inferences [Horsten]
     Full Idea: We should not aim at describing the nature of truth because there is no such thing. Rather, we should aim at describing the inferential behaviour of truth.
     From: Leon Horsten (The Tarskian Turn [2011], 10.2.3)
3. Truth / A. Truth Problems / 5. Truth Bearers
Propositions have sentence-like structures, so it matters little which bears the truth [Horsten]
     Full Idea: It makes little difference, at least in extensional contexts, whether the truth bearers are propositions or sentences (or assertions). Even if the bearers are propositions rather than sentences, propositions are structured rather like sentences.
     From: Leon Horsten (The Tarskian Turn [2011], 02.4)
     A reaction: The 'extensional' context means you are only talking about the things that are referred to, and not about the way this is expressed. I prefer propositions, but this is an interesting point.
3. Truth / C. Correspondence Truth / 2. Correspondence to Facts
Modern correspondence is said to be with the facts, not with true propositions [Horsten]
     Full Idea: Modern correspondence theorists no longer take things to correspond to true propositions; they consider facts to be the truthmakers of propositions.
     From: Leon Horsten (The Tarskian Turn [2011], 02.1)
     A reaction: If we then define facts as the way certain things are, independently from our thinking about it, at least we seem to be avoiding circularity. Not much point in correspondence accounts if you are not a robust realist (like me). [14,000th idea, 23/4/12!]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
The correspondence 'theory' is too vague - about both 'correspondence' and 'facts' [Horsten]
     Full Idea: The principle difficulty of the correspondence theory of truth is its vagueness. It is too vague to be called a theory until more information is given about what is meant by the terms 'correspondence' and 'fact'. Facts can involve a heavy ontology.
     From: Leon Horsten (The Tarskian Turn [2011], 02.1)
     A reaction: I see nothing here to make me give up my commitment to the correspondence view of truth, though it sounds as if I will have to give up the word 'theory' in that context. Truth is so obviously about thought fitting reality that there is nothing to discuss.
3. Truth / D. Coherence Truth / 2. Coherence Truth Critique
The coherence theory allows multiple coherent wholes, which could contradict one another [Horsten]
     Full Idea: The coherence theory seems too liberal. It seems there can be more than one systematic whole which, while being internally coherent, contradict each other, and thus cannot all be true. Coherence is a necessary but not sufficient condition for truth.
     From: Leon Horsten (The Tarskian Turn [2011], 02.1)
     A reaction: This is a modern post-Tarski axiomatic truth theorist making very short work indeed of the coherence theory of truth. I take Horsten to be correct.
3. Truth / E. Pragmatic Truth / 1. Pragmatic Truth
The pragmatic theory of truth is relative; useful for group A can be useless for group B [Horsten]
     Full Idea: The pragmatic theory is unsatisfactory because usefulness is a relative notion. One theory can be useful to group A while being thoroughly impractical for group B. This would make the theory both truth and false.
     From: Leon Horsten (The Tarskian Turn [2011], 02.1)
     A reaction: This objection, along with the obvious fact that certain falsehoods can be very useful, would seem to rule pragmatism out as a theory of truth. It is, in fact, an abandonment of truth.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
Tarski's hierarchy lacks uniform truth, and depends on contingent factors [Horsten]
     Full Idea: According to the Tarskian hierarchical conception, truth is not a uniform notion. ...Also Kripke has emphasised that the level of a token of the truth predicate can depend on contingent factors, such as what else has been said by a speaker.
     From: Leon Horsten (The Tarskian Turn [2011], 04.5)
Tarski Bi-conditional: if you'll assert φ you'll assert φ-is-true - and also vice versa [Horsten]
     Full Idea: The axiom schema 'Sentence "phi;" is true iff φ' is the (unrestricted) Tarski-Biconditional, and is motivated by the thought that if you are willing to assume or outright assert that φ, you will assert that φ is true - and also vice versa.
     From: Leon Horsten (The Tarskian Turn [2011], 02.2)
     A reaction: Very helpful! Most people are just bewildered by the Tarski bi-conditional ('"Snow is white"...), but this formulation nicely shows its minimal character while showing that it really does say something. It says what truths and truth-claims commit you to.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / c. Meta-language for truth
Semantic theories have a regress problem in describing truth in the languages for the models [Horsten]
     Full Idea: Semantic theories give a class of models with a truth predicate, ...but Tarski taught us that this needs a more encompassing framework than its language...so how is the semantics of the framework expressed? The model route has a regress.
     From: Leon Horsten (The Tarskian Turn [2011], 02.3)
     A reaction: [compressed] So this regress problem, of endless theories of truth going up the hierarchy, is Horsten's main reason for opting for axiomatic theories, which he then tries to strengthen, so that they are not quite so deflated.
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
Axiomatic approaches avoid limiting definitions to avoid the truth predicate, and limited sizes of models [Horsten]
     Full Idea: An adequate definition of truth can only be given for the fragment of our language that does not contain the truth predicate. A model can never encompass the whole of the domain of discourse of our language. The axiomatic approach avoids these problems.
     From: Leon Horsten (The Tarskian Turn [2011], 10.1)
Axiomatic approaches to truth avoid the regress problem of semantic theories [Horsten]
     Full Idea: The axiomatic approach to truth does not suffer from the regress problem.
     From: Leon Horsten (The Tarskian Turn [2011], 02.3)
     A reaction: See Idea 15345 for the regress problem. The difficulty then seems to be that axiomatic approaches lack expressive power, so the hunt is on for a set of axioms which will do a decent job. Fun work, if you can cope with it.
An axiomatic theory needs to be of maximal strength, while being natural and sound [Horsten]
     Full Idea: The challenge is to find the arithmetically strongest axiomatical truth theory that is both natural and truth-theoretically sound.
     From: Leon Horsten (The Tarskian Turn [2011], 07.7)
'Reflexive' truth theories allow iterations (it is T that it is T that p) [Horsten]
     Full Idea: A theory of truth is 'reflexive' if it allows us to prove truth-iterations ("It is true that it is true that so-and-so").
     From: Leon Horsten (The Tarskian Turn [2011], 01.4)
A good theory of truth must be compositional (as well as deriving biconditionals) [Horsten]
     Full Idea: Deriving many Tarski-biconditionals is not a sufficient condition for being a good theory of truth. A good theory of truth must in addition do justice to the compositional nature of truth.
     From: Leon Horsten (The Tarskian Turn [2011], 06.1)
The Naďve Theory takes the bi-conditionals as axioms, but it is inconsistent, and allows the Liar [Horsten]
     Full Idea: The Naďve Theory of Truth collects all the Tarski bi-conditionals of a language and takes them as axioms. But no consistent theory extending Peano arithmetic can prove all of them. It is inconsistent, and even formalises the liar paradox.
     From: Leon Horsten (The Tarskian Turn [2011], 03.5.2)
     A reaction: [compressed] This looks to me like the account of truth that Davidson was working with, since he just seemed to be compiling bi-conditionals for tricky cases. (Wrong! He championed the Compositional Theory, Horsten p.71)
Axiomatic theories take truth as primitive, and propose some laws of truth as axioms [Horsten]
     Full Idea: In the axiomatic approach we take the truth predicate to express an irreducible, primitive notion. The meaning of the truth predicate is partially explicated by proposing certain laws of truth as basic principles, as axioms.
     From: Leon Horsten (The Tarskian Turn [2011], 04.2)
     A reaction: Judging by Horsten's book, this is a rather fruitful line of enquiry, but it still seems like a bit of a defeat to take truth as 'primitive'. Presumably you could add some vague notion of correspondence as the background picture.
By adding truth to Peano Arithmetic we increase its power, so truth has mathematical content! [Horsten]
     Full Idea: It is surprising that just by adding to Peano Arithmetic principles concerning the notion of truth, we increase the mathematical strength of PA. So, contrary to expectations, the 'philosophical' notion of truth has real mathematical content.
     From: Leon Horsten (The Tarskian Turn [2011], 06.4)
     A reaction: Horsten invites us to be really boggled by this. All of this is in the Compositional Theory TC. It enables a proof of the consistency of arithmetic (but still won't escape Gödel's Second).
3. Truth / G. Axiomatic Truth / 2. FS Truth Axioms
Friedman-Sheard theory keeps classical logic and aims for maximum strength [Horsten]
     Full Idea: The Friedman-Sheard theory of truth holds onto classical logic and tries to construct a theory that is as strong as possible.
     From: Leon Horsten (The Tarskian Turn [2011], 01.4)
3. Truth / G. Axiomatic Truth / 3. KF Truth Axioms
Kripke-Feferman has truth gaps, instead of classical logic, and aims for maximum strength [Horsten]
     Full Idea: If we abandon classical logic in favour of truth-value gaps and try to strengthen the theory, this leads to the Kripke-Feferman theory of truth, and variants of it.
     From: Leon Horsten (The Tarskian Turn [2011], 01.4)
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Inferential deflationism says truth has no essence because no unrestricted logic governs the concept [Horsten]
     Full Idea: According to 'inferential deflationism', truth is a concept without a nature or an essence. This is betrayed by the fact that there are no unrestricted logical laws that govern the concept of truth.
     From: Leon Horsten (The Tarskian Turn [2011], 01.1)
Deflationism skips definitions and models, and offers just accounts of basic laws of truth [Horsten]
     Full Idea: Contemporary deflationism about truth does not attempt to define truth, and does not rely on models containing the truth predicate. Instead they are interpretations of axiomatic theories of truth, containing only basic laws of truth.
     From: Leon Horsten (The Tarskian Turn [2011], 02.3)
Deflationism concerns the nature and role of truth, but not its laws [Horsten]
     Full Idea: Deflationism is not a theory of the laws of truth. It is a view on the nature and role of the concept of truth.
     From: Leon Horsten (The Tarskian Turn [2011], 05 Intro)
This deflationary account says truth has a role in generality, and in inference [Horsten]
     Full Idea: On the conception of deflationism developed in this book, the prime positive role of the truth predicate is to serve as a device for expressing generalities, and an inferential tool.
     From: Leon Horsten (The Tarskian Turn [2011], 07.5)
Deflationism says truth isn't a topic on its own - it just concerns what is true [Horsten]
     Full Idea: Deflationism says the theory of truth does not have a substantial domain of its own. The domain of the theory of truth consists of the bearers of truth.
     From: Leon Horsten (The Tarskian Turn [2011], 05.1)
     A reaction: The immediate thought is that truth also concerns falsehoods, which would be inexplicable without it. If physics just concerns the physical, does that mean that physics lacks its own 'domain'? Generalising about the truths is a topic.
Deflation: instead of asserting a sentence, we can treat it as an object with the truth-property [Horsten]
     Full Idea: The Deflationary view just says that instead of asserting a sentence, we can turn the sentence into an object and assert that this object has the property of truth.
     From: Leon Horsten (The Tarskian Turn [2011], 05.2.2)
     A reaction: That seems to leave a big question hanging, which concerns the nature of the property that is being attributed to this object. Quine 1970:10-13 says it is just a 'device'. Surely you can rest content with that as an account of truth?
4. Formal Logic / E. Nonclassical Logics / 1. Nonclassical Logics
Nonclassical may accept T/F but deny applicability, or it may deny just T or F as well [Horsten]
     Full Idea: Some nonclassical logic stays close to classical, assuming two mutually exclusive truth values T and F, but some sentences fail to have one. Others have further truth values such as 'half truth', or dialethists allow some T and F at the same time.
     From: Leon Horsten (The Tarskian Turn [2011], 01.2)
     A reaction: I take that to say that the first lot accept bivalence but reject excluded middle (allowing 'truth value gaps'), while the second lot reject both. Bivalence gives the values available, and excluded middle says what has them.
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Doubt is thrown on classical logic by the way it so easily produces the liar paradox [Horsten]
     Full Idea: Aside from logic, so little is needed to generate the liar paradox that one wonders whether the laws of classical logic are unrestrictedly valid after all. (Many theories of truth have therefore been formulated in nonclassical logic.)
     From: Leon Horsten (The Tarskian Turn [2011], 01.2)
     A reaction: Kripke uses Strong Kleene logic for his theory. The implication is that debates discussed by Horsten actually have the status of classical logic at stake, as well as the nature of truth.
5. Theory of Logic / B. Logical Consequence / 5. Modus Ponens
Deduction Theorem: ψ only derivable from φ iff φ→ψ are axioms [Horsten]
     Full Idea: The Deduction Theorem says ψ is derivable in classical predicate logic from ψ iff the sentence φ→ψ is a theorem of classical logic. Hence inferring φ to ψ is truth-preserving iff the axiom scheme φ→ψ is provable.
     From: Leon Horsten (The Tarskian Turn [2011], 02.2)
     A reaction: Horsten offers this to show that the Tarski bi-conditionals can themselves be justified, and not just the rule of inference involved. Apparently you can only derive something if you first announce that you have the ability to derive it. Odd.
5. Theory of Logic / E. Structures of Logic / 8. Theories in Logic
A theory is 'non-conservative' if it facilitates new mathematical proofs [Horsten]
     Full Idea: A theory is 'non-conservative' if it allows us to prove mathematical facts that go beyond what the background mathematical theory can prove on its own.
     From: Leon Horsten (The Tarskian Turn [2011], 01.4)
     A reaction: This is an instance of the relationship with mathematics being used as the test case for explorations of logic. It is a standard research method, because it is so precise, but should not be mistaken for the last word about a theory.
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
It is easier to imagine truth-value gaps (for the Liar, say) than for truth-value gluts (both T and F) [Horsten]
     Full Idea: It is easier to imagine what it is like for a sentence to lack a truth value than what it is like for a sentence to be both truth and false. So I am grudgingly willing to entertain the possibility that certain sentences (like the Liar) lack a truth value.
     From: Leon Horsten (The Tarskian Turn [2011], 02.5)
     A reaction: Fans of truth value gluts are dialethists like Graham Priest. I'm with Horsten on this one. But in what way can a sentence be meaningful if it lacks a truth-value? He mentions unfulfilled presuppositions and indicative conditionals as gappy.
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
Satisfaction is a primitive notion, and very liable to semantical paradoxes [Horsten]
     Full Idea: Satisfaction is a more primitive notion than truth, and it is even more susceptible to semantical paradoxes than the truth predicate.
     From: Leon Horsten (The Tarskian Turn [2011], 06.3)
     A reaction: The Liar is the best known paradox here. Tarski bases his account of truth on this primitive notion, so Horsten is pointing out the difficulties.
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
A theory is 'categorical' if it has just one model up to isomorphism [Horsten]
     Full Idea: If a theory has, up to isomorphism, exactly one model, then it is said to be 'categorical'.
     From: Leon Horsten (Philosophy of Mathematics [2007], §5.2)
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
The first incompleteness theorem means that consistency does not entail soundness [Horsten]
     Full Idea: It is a lesson of the first incompleteness theorem that consistency does not entail soundness. If we add the negation of the gödel sentence for PA as an extra axiom to PA, the result is consistent. This negation is false, so the theory is unsound.
     From: Leon Horsten (The Tarskian Turn [2011], 04.3)
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
Strengthened Liar: 'this sentence is not true in any context' - in no context can this be evaluated [Horsten]
     Full Idea: The Strengthened Liar sentence says 'this sentence is not true in any context'. It is not hard to figure out that there is no context in which the sentence can be coherently evaluated.
     From: Leon Horsten (The Tarskian Turn [2011], 04.6)
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
English expressions are denumerably infinite, but reals are nondenumerable, so many are unnameable [Horsten]
     Full Idea: The number of English expressions is denumerably infinite. But Cantor's theorem can be used to show that there are nondenumerably many real numbers. So not every real number has a (simple or complex name in English).
     From: Leon Horsten (The Tarskian Turn [2011], 06.3)
     A reaction: This really bothers me. Are we supposed to be committed to the existence of entities which are beyond our powers of naming? How precise must naming be? If I say 'pick a random real number', might that potentially name all of them?
6. Mathematics / B. Foundations for Mathematics / 2. Proof in Mathematics
Computer proofs don't provide explanations [Horsten]
     Full Idea: Mathematicians are uncomfortable with computerised proofs because a 'good' proof should do more than convince us that a certain statement is true. It should also explain why the statement in question holds.
     From: Leon Horsten (Philosophy of Mathematics [2007], §5.3)
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
The concept of 'ordinal number' is set-theoretic, not arithmetical [Horsten]
     Full Idea: The notion of an ordinal number is a set-theoretic, and hence non-arithmetical, concept.
     From: Leon Horsten (Philosophy of Mathematics [2007], §2.3)
ZFC showed that the concept of set is mathematical, not logical, because of its existence claims [Horsten]
     Full Idea: One of the strengths of ZFC is that it shows that the concept of set is a mathematical concept. Many originally took it to be a logical concept. But ZFC makes mind-boggling existence claims, which should not follow if it was a logical concept.
     From: Leon Horsten (The Tarskian Turn [2011], 05.2.3)
     A reaction: This suggests that set theory is not just a way of expressing mathematics (see Benacerraf 1965), but that some aspect of mathematics has been revealed by it - maybe even its essential nature.
Set theory is substantial over first-order arithmetic, because it enables new proofs [Horsten]
     Full Idea: The nonconservativeness of set theory over first-order arithmetic has done much to establish set theory as a substantial theory indeed.
     From: Leon Horsten (The Tarskian Turn [2011], 07.5)
     A reaction: Horsten goes on to point out the price paid, which is the whole new ontology which has to be added to the arithmetic. Who cares? It's all fictions anyway!
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
Predicativism says mathematical definitions must not include the thing being defined [Horsten]
     Full Idea: Predicativism has it that a mathematical object (such as a set of numbers) cannot be defined by quantifying over a collection that includes that same mathematical object. To do so would be a violation of the vicious circle principle.
     From: Leon Horsten (The Tarskian Turn [2011], 07.7)
     A reaction: In other words, when you define an object you are obliged to predicate something new, and not just recycle the stuff you already have.
7. Existence / C. Structure of Existence / 3. Levels of Reality
A necessary relation between fact-levels seems to be a further irreducible fact [Lynch/Glasgow]
     Full Idea: It seems unavoidable that the facts about logically necessary relations between levels of facts are themselves logically distinct further facts, irreducible to the microphysical facts.
     From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], C)
     A reaction: I'm beginning to think that rejecting every theory of reality that is proposed by carefully exposing some infinite regress hidden in it is a rather lazy way to do philosophy. Almost as bad as rejecting anything if it can't be defined.
7. Existence / C. Structure of Existence / 5. Supervenience / c. Significance of supervenience
If some facts 'logically supervene' on some others, they just redescribe them, adding nothing [Lynch/Glasgow]
     Full Idea: Logical supervenience, restricted to individuals, seems to imply strong reduction. It is said that where the B-facts logically supervene on the A-facts, the B-facts simply re-describe what the A-facts describe, and the B-facts come along 'for free'.
     From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], C)
     A reaction: This seems to be taking 'logically' to mean 'analytically'. Presumably an entailment is logically supervenient on its premisses, and may therefore be very revealing, even if some people think such things are analytic.
7. Existence / D. Theories of Reality / 6. Physicalism
Nonreductive materialism says upper 'levels' depend on lower, but don't 'reduce' [Lynch/Glasgow]
     Full Idea: The root intuition behind nonreductive materialism is that reality is composed of ontologically distinct layers or levels. …The upper levels depend on the physical without reducing to it.
     From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], B)
     A reaction: A nice clear statement of a view which I take to be false. This relationship is the sort of thing that drives people fishing for an account of it to use the word 'supervenience', which just says two things seem to hang out together. Fluffy materialism.
The hallmark of physicalism is that each causal power has a base causal power under it [Lynch/Glasgow]
     Full Idea: Jessica Wilson (1999) says what makes physicalist accounts different from emergentism etc. is that each individual causal power associated with a supervenient property is numerically identical with a causal power associated with its base property.
     From: Lynch,MP/Glasgow,JM (The Impossibility of Superdupervenience [2003], n 11)
     A reaction: Hence the key thought in so-called (serious, rather than self-evident) 'emergentism' is so-called 'downward causation', which I take to be an idle daydream.
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
We may believe in atomic facts, but surely not complex disjunctive ones? [Horsten]
     Full Idea: While positive and perhaps even negative atomic facts may be unproblematic, it seems excessive to commit oneself to the existence of logically complex facts such as disjunctive facts.
     From: Leon Horsten (The Tarskian Turn [2011], 02.1)
     A reaction: Presumably it is hard to deny that very complex statements involving massive disjunctions can be true or false. But why does commitment to real facts have to involve a huge ontology? The ontology is just the ingredients of the fact, isn't it?
7. Existence / D. Theories of Reality / 10. Vagueness / f. Supervaluation for vagueness
In the supervaluationist account, disjunctions are not determined by their disjuncts [Horsten]
     Full Idea: If 'Britain is large' and 'Italy is large' lack truth values, then so must 'Britain or Italy is large' - so on the supervaluationist account the truth value of a disjunction is not determined by the truth values of its disjuncts.
     From: Leon Horsten (The Tarskian Turn [2011], 06.2)
     A reaction: Compare Idea 15362 to get the full picture here.
If 'Italy is large' lacks truth, so must 'Italy is not large'; but classical logic says it's large or it isn't [Horsten]
     Full Idea: If 'Italy is a large country' lacks a truth value, then so too, presumably, does 'Italy is not a large country'. But 'Italy is or is not a large country' is true, on the supervaluationist account, because it is a truth of classical propositional logic.
     From: Leon Horsten (The Tarskian Turn [2011], 06.2)
     A reaction: See also Idea 15363. He cites Fine 1975.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / d. Dispositions as occurrent
There doesn't seem to be anything in the actual world that can determine modal facts [Sidelle]
     Full Idea: Metaphysically, nothing in the actual world seems to be a candidate for determining what is necessarily the case.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.4)
     A reaction: I file this under 'Dispositions' to show what is at stake in the debate about dispositional and categorical properties. I take a commitment to dispositions to be a commitment to modal facts about the actual world.
9. Objects / D. Essence of Objects / 2. Types of Essence
Causal reference presupposes essentialism if it refers to modally extended entities [Sidelle]
     Full Idea: Even if the causal theory of reference proper does not presuppose essentialism, it does presuppose essentialism if it is to be an account of reference to modally extended entities.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.6)
9. Objects / D. Essence of Objects / 7. Essence and Necessity / c. Essentials are necessary
Clearly, essential predications express necessary properties [Sidelle]
     Full Idea: It is clear, of course, that if there are true essential predications, then they express necessary properties.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.2)
     A reaction: I would certainly want to ask whether essences have to be analysed as properties, and also (more boldly) whether there might not be contingent essences.
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
Being a deepest explanatory feature is an actual, not a modal property [Sidelle]
     Full Idea: The property of being a deepest explanatory feature is a nonmodal property: it's an actual property.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.4)
     A reaction: I don't accept the existence of properties of the form 'being-F'. The possibility of securing a door may be the deepest explanatory feature of a lock. [To be fair to Sidelle, see context - just for once!] Dispositions are actual.
9. Objects / D. Essence of Objects / 15. Against Essentialism
That the essence of water is its microstructure is a convention, not a discovery [Sidelle]
     Full Idea: The necessity to water of whatever is found out to be the water's microstructure is given by convention, and is not something which is discovered.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.2)
     A reaction: A powerful point. It shows the authority of science that we accept the microstructure as the essence. The essences of statues and people are definitely not their microstructures. One H2O molecule isn't water. Why not? Macro-properties count too!
9. Objects / F. Identity among Objects / 3. Relative Identity
We aren't clear about 'same stuff as this', so a principle of individuation is needed to identify it [Sidelle]
     Full Idea: Independent of conventions, no definite sense can be given to the notion of 'the same stuff as this'. So reference-fixing must include some principle of individuation to determine the aspects of sameness for the identity referred to.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.6)
     A reaction: Is he really saying that we don't understand 'same stuff as this'? Surely animals can manage that, and they are not famous for their conventions. Sidelle has fallen into the sortalist trap, I think.
10. Modality / A. Necessity / 4. De re / De dicto modality
Evaluation of de dicto modalities does not depend on the identity of its objects [Sidelle]
     Full Idea: In the evaluation of de dicto modal statements, whether some possible state of affairs is relevant to its truth does not depend on the identity of its objects, as in 'Necessarily, the President of the USA is male'.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.3)
     A reaction: This is a more clear-cut and easy to grasp criterion than most that are on offer.
10. Modality / C. Sources of Modality / 3. Necessity by Convention
Necessary a posteriori is conventional for necessity and nonmodal for a posteriority [Sidelle, by Sider]
     Full Idea: Sidelle defends conventionalism against a posteriori necessities by 'factoring' a necessary a posteriori truth into an analytic component and a nonmodal component. The modal force then comes from the analytic part, and the a posteriority from the other.
     From: report of Alan Sidelle (Necessity, Essence and Individuation [1989]) by Theodore Sider - Writing the Book of the World 12.8
     A reaction: [I note that Sidelle refers, it seems, to the nonmodal component as a 'deep explanatory feature', which is exactly what I take an essence to be].
To know empirical necessities, we need empirical facts, plus conventions about which are necessary [Sidelle]
     Full Idea: What we need to know, in order to know what is empirically necessary, is some empirical fact plus our conventions that tell us which truths are necessary given which empirical facts.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.4)
     A reaction: I take this attack on a posteriori necessities to be the most persuasive part of Sidelle's case, but you can't just put all of our truths down to convention. There are stabilities in the world, as well as in our conventions.
10. Modality / D. Knowledge of Modality / 3. A Posteriori Necessary
The necessary a posteriori is statements either of identity or of essence [Sidelle]
     Full Idea: The necessary a posteriori crudely divides into two groups - (synthetic) identity statements (between rigid designators), and statements of essential properties. The latter is either statements of property identity, or of the essences of natural kinds.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.2)
     A reaction: He cites Kripke's examples (Hesperus,Cicero,Truman,water,gold), and divides them into the two groups. Helpful.
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
Empiricism explores necessities and concept-limits by imagining negations of truths [Sidelle]
     Full Idea: In the traditional empiricist picture, we go about modal enquiry by trying to see whether we can imagine a situation in which it would be correct to assert the negation of a proposed necessary truth. Thus we can find out the limits of our concepts.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.1)
Contradictoriness limits what is possible and what is imaginable [Sidelle]
     Full Idea: Contradictoriness is the boundary both of what is possible and also of what is imaginable.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.4)
     A reaction: Of course we may see contradictions where there are none, and fail to grasp real hidden contradictions, so the two do not coincide in the practice. I think I would say it is 'a' boundary, not 'the' boundary.
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
The individuals and kinds involved in modality are also a matter of convention [Sidelle]
     Full Idea: It is not merely the modal facts that result from our conventions, but the individuals and kinds that are modally involved.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.3)
     A reaction: I am beginning to find Sidelle's views very sympathetic - going over to the Dark Side, I'm afraid. But conventions won't work at all if they don't correspond closely to reality.
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
A thing doesn't need transworld identity prior to rigid reference - that could be a convention of the reference [Sidelle]
     Full Idea: For a term to be rigid, it is said there must be real transworld identity prior to our use of the rigid term, ..but this may only be because we have conventional principles for individuating across worlds. 'Let's call him Fred' - perhaps explicitly rigid.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.3)
     A reaction: This seems right. An example might be a comic book character, who retains a perfect identity in all the comics, with no scars, weight change, or ageing.
'Dthat' operates to make a singular term into a rigid term [Sidelle]
     Full Idea: 'Dthat' is Kaplan's indexical operator; it operates on a given singular term, φ, and makes it into a rigid designator of whatever φ designates in the original context.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.6 n11)
     A reaction: I like this idea a lot, because it strikes me that referring to something rigidly is a clear step beyond referring to it in actuality. I refer to 'whoever turns up each week', but that is hardly rigid. The germ of 2-D semantics is here.
11. Knowledge Aims / A. Knowledge / 4. Belief / c. Aim of beliefs
Some claim that indicative conditionals are believed by people, even though they are not actually held true [Horsten]
     Full Idea: In the debate about doxastic attitudes towards indicative conditional sentences, one finds philosophers who claim that conditionals can be believed even though they have no truth value (and thus are not true).
     From: Leon Horsten (The Tarskian Turn [2011], 09.3)
12. Knowledge Sources / A. A Priori Knowledge / 8. A Priori as Analytic
A priori knowledge is entirely of analytic truths [Sidelle]
     Full Idea: The a priori method yields a priori knowledge, and the objects of this knowledge are not facts about the world, but analytic truths.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.1)
     A reaction: Are we not allowed any insights at all into how the world must be, independent of how we happen to conceptualise it?
18. Thought / C. Content / 5. Twin Earth
That water is essentially H2O in some way concerns how we use 'water' [Sidelle]
     Full Idea: If water is essentially H2O, this is going to have something to do with our intentions in using 'water'.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.1)
     A reaction: This very simple point looks to be correct, and raises very important questions about the whole Twin Earth thing. When new discoveries are made, words shift their meanings. We're not quite sure what 'jade' means any more.
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
Causal reference seems to get directly at the object, thus leaving its nature open [Sidelle]
     Full Idea: The causal theory of reference appears to give us a way to get at an object while leaving it undetermined what its essence or necessary features might be.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.1)
     A reaction: This pinpoints why the direct/causal theory of reference seems to open the doors to scientific essentialism. Sidelle, of course, opposes the whole programme.
19. Language / B. Reference / 5. Speaker's Reference
Because some entities overlap, reference must have analytic individuation principles [Sidelle]
     Full Idea: The phenomenon of overlapping entities requires that if our reference is to be determinate (as determinate as it is), then there must be analytic principles of individuation.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.5)
     A reaction: His point is that there is something inescapably conventional about the way in which our reference works. It isn't just some bald realist baptism.
19. Language / C. Assigning Meanings / 1. Syntax
A theory of syntax can be based on Peano arithmetic, thanks to the translation by Gödel coding [Horsten]
     Full Idea: A notion of formal provability can be articulated in Peano arithmetic. ..This is surprisingly 'linguistic' rather than mathematical, but the key is in the Gödel coding. ..Hence we use Peano arithmetic as a theory of syntax.
     From: Leon Horsten (The Tarskian Turn [2011], 02.4)
     A reaction: This is the explanation of why issues in formal semantics end up being studied in systems based on formal arithmetic. And I had thought it was just because they were geeks who dream in numbers, and can't speak language properly...
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / e. Anti scientific essentialism
Can anything in science reveal the necessity of what it discovers? [Sidelle]
     Full Idea: Is there anything in the procedures of scientists that could reveal to them that water is necessarily H2O or that gold necessarily has atomic number 79.
     From: Alan Sidelle (Necessity, Essence and Individuation [1989], Ch.4)
     A reaction: This is Leibniz's is view, that empirical evidence can never reveal necessities. Given that we know some necessities, you have an argument for rationalism.