Combining Philosophers

All the ideas for H.Putnam/P.Oppenheim, Alexander Bird and Volker Halbach

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156 ideas

1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
Analysis rests on natural language, but its ideal is a framework which revises language [Halbach]
     Full Idea: For me, although the enterprise of philosophical analysis is driven by natural language, its goal is not a linguistic analysis of English but rather an expressively strong framework that may at best be seen as a revision of English.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 12)
     A reaction: I agree, but the problem is that there are different ideals for the revision, which may be in conflict. Logicians, mathematicians, metaphysicians, scientists, moralists and aestheticians are queueing up to improve in their own way.
1. Philosophy / G. Scientific Philosophy / 1. Aims of Science
Instrumentalists say distinctions between observation and theory vanish with ostensive definition [Bird]
     Full Idea: Instrumentalists treat the theoretical/non-theoretical and the observational/non-observational distinctions as the same, ..because they think words get their meaning by way of ostensive definition.
     From: Alexander Bird (Philosophy of Science [1998], Ch.4)
     A reaction: To be honest, I'm not sure I quite understand this, but it sounds interesting... Ostensive definition seems to match the pragmatic spirit of instrumentalism (for which, see Idea 6778). Bird explains it all more fully.
2. Reason / D. Definition / 2. Aims of Definition
An explicit definition enables the elimination of what is defined [Halbach]
     Full Idea: Explicit definitions allow for a complete elimination of the defined notion (at least in extensional contexts).
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 1)
     A reaction: If the context isn't extensional (concerning the things themselves) then we could define one description of it, but be unable to eliminate it under another description. Elimination is no the aim of an Aristotelian definition. Halbach refers to truth.
2. Reason / E. Argument / 3. Analogy
Don't trust analogies; they are no more than a guideline [Halbach]
     Full Idea: Arguments from analogy are to be distrusted: at best they can serve as heuristics.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 4)
3. Truth / A. Truth Problems / 1. Truth
Truth-value 'gluts' allow two truth values together; 'gaps' give a partial conception of truth [Halbach]
     Full Idea: Truth-value 'gluts' correspond to a so-called dialethic conception of truth; excluding gluts and admitting only 'gaps' leads to a conception of what is usually called 'partial' truth.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 15.2)
     A reaction: Talk of 'gaps' and 'gluts' seem to be the neatest way of categorising views of truth. I want a theory with no gaps or gluts.
Truth axioms prove objects exist, so truth doesn't seem to be a logical notion [Halbach]
     Full Idea: Two typed disquotation sentences, truth axioms of TB, suffice for proving that there at least two objects. Hence truth is not a logical notion if one expects logical notions to be ontologically neutral.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 21.2)
3. Truth / A. Truth Problems / 2. Defining Truth
Any definition of truth requires a metalanguage [Halbach]
     Full Idea: It is plain that the distinction between object and metalanguage is required for the definability of truth.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 11)
     A reaction: Halbach's axiomatic approach has given up on definability, and therefore it can seek to abandon the metalanguage and examine 'type-free' theories.
Truth definitions don't produce a good theory, because they go beyond your current language [Halbach]
     Full Idea: It is far from clear that a definition of truth can lead to a philosophically satisfactory theory of truth. Tarski's theorem on the undefinability of the truth predicate needs resources beyond those of the language for which it is being defined.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1)
     A reaction: The idea is that you need a 'metalanguage' for the definition. If I say 'p' is a true sentence in language 'L', I am not making that observation from within language L. The dream is a theory confined to the object language.
Traditional definitions of truth often make it more obscure, rather than less [Halbach]
     Full Idea: A common complaint against traditional definitional theories of truth is that it is far from clear that the definiens is not more in need of clarification than the definiendum (that is, the notion of truth).
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 1)
     A reaction: He refers to concepts like 'correspondence', 'facts', 'coherence' or 'utility', which are said to be trickier to understand than 'true'. I suspect that philosophers like Halbach confuse 'clear' with 'precise'. Coherence is quite clear, but imprecise.
If people have big doubts about truth, a definition might give it more credibility [Halbach]
     Full Idea: If one were wondering whether truth should be considered a legitimate notion at all, a definition might be useful in dispersing doubts about its legitimacy.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 3)
     A reaction: Halbach is proposing to skip definitions, and try to give rules for using 'true' instead, but he doesn't rule out definitions. A definition of 'knowledge' or 'virtue' or 'democracy' might equally give those credibility.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / c. Meta-language for truth
In semantic theories of truth, the predicate is in an object-language, and the definition in a metalanguage [Halbach]
     Full Idea: In semantic theories of truth (Tarski or Kripke), a truth predicate is defined for an object-language. This definition is carried out in a metalanguage, which is typically taken to include set theory or another strong theory or expressive language.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1)
     A reaction: Presumably the metalanguage includes set theory because that connects it with mathematics, and enables it to be formally rigorous. Tarski showed, in his undefinability theorem, that the meta-language must have increased resources.
Semantic theories avoid Tarski's Theorem by sticking to a sublanguage [Halbach]
     Full Idea: In semantic theories (e.g.Tarski's or Kripke's), a definition evades Tarski's Theorem by restricting the possible instances in the schema T[φ]↔φ to sentences of a proper sublanguage of the language formulating the equivalences.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 1)
     A reaction: The schema says if it's true it's affirmable, and if it's affirmable it's true. The Liar Paradox is a key reason for imposing this restriction.
3. Truth / F. Semantic Truth / 2. Semantic Truth
Disquotational truth theories are short of deductive power [Halbach]
     Full Idea: The problem of restricted deductive power has haunted disquotational theories of truth (…because they can't prove generalisations).
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 19.5)
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach]
     Full Idea: Axiomatic theories of truth can be presented within very weak logical frameworks which require very few resources, and avoid the need for a strong metalanguage and metatheory.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1)
CT proves PA consistent, which PA can't do on its own, so CT is not conservative over PA [Halbach]
     Full Idea: Compositional Truth CT proves the consistency of Peano arithmetic, which is not provable in Peano arithmetic by Gödel's second incompleteness theorem. Hence the theory CT is not conservative over Peano arithmetic.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 8.6)
If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [Halbach]
     Full Idea: If truth can be explicitly defined, it can be eliminated, whereas an axiomatized notion of truth may bring all kinds of commitments.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3)
     A reaction: The general principle that anything which can be defined can be eliminated (in an abstract theory, presumably, not in nature!) raises interesting questions about how many true theories there are which are all equivalent to one another.
Axiomatic truth doesn't presuppose a truth-definition, though it could admit it at a later stage [Halbach]
     Full Idea: Choosing an axiomatic approach to truth might well be compatible with the view that truth is definable; the definability of truth is just not presupposed at the outset.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 1)
     A reaction: Is it possible that a successful axiomatisation is a successful definition?
The main semantic theories of truth are Kripke's theory, and revisions semantics [Halbach]
     Full Idea: Revision semantics is arguably the main competitor of Kripke's theory of truth among semantic truth theories. …In the former one may hope through revision to arrive at better and better models, ..sorting out unsuitable extensions of the truth predicate.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 14)
     A reaction: Halbach notes later that Kripke's theory (believe it or not) is considerably simpler than revision semantics.
To axiomatise Tarski's truth definition, we need a binary predicate for his 'satisfaction' [Halbach]
     Full Idea: If the clauses of Tarski's definition of truth are turned into axioms (as Davidson proposed) then a primitive binary predicate symbol for satisfaction is needed, as Tarski defined truth in terms of satisfaction. Standard language has a unary predicate.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 5.2)
Compositional Truth CT has the truth of a sentence depending of the semantic values of its constituents [Halbach]
     Full Idea: In the typed Compositional Truth theory CT, it is compositional because the truth of a sentence depends on the semantic values of the constituents of that sentence.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 8)
     A reaction: [axioms on p. 65 of Halbach]
Gödel numbering means a theory of truth can use Peano Arithmetic as its base theory [Halbach]
     Full Idea: Often syntactic objects are identified with their numerical codes. …Expressions of a countable formal language can be coded in the natural numbers. This allows a theory of truth to use Peano Arithmetic (with its results) as a base theory.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 2)
     A reaction: The numbering system is the famous device invented by Gödel for his great proof of incompleteness. This idea is a key to understanding modern analytic philosophy. It is the bridge which means philosophical theories can be treated mathematically.
Truth axioms need a base theory, because that is where truth issues arise [Halbach]
     Full Idea: Considering the truth axioms in the absence of a base theory is not very sensible because characteristically truth theoretic reasoning arises from the interplay of the truth axioms with the base theory.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 21.2)
     A reaction: The base theory usually seems to be either Peano arithmetic or set theory. We might say that introverted thought (e.g. in infants) has little use for truth; it is when you think about the world that truth becomes a worry.
We know a complete axiomatisation of truth is not feasible [Halbach]
     Full Idea: In the light of incompleteness phenomena, one should not expect a categorical axiomatisation of truth to be feasible, but this should not keep one from studying axiomatic theories of truth (or of arithmetic).
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 3)
     A reaction: This, of course, is because of Gödel's famous results. It is important to be aware in this field that there cannot be a dream of a final theory, so we are just seeing what can be learned about truth.
A theory is 'conservative' if it adds no new theorems to its base theory [Halbach, by PG]
     Full Idea: A truth theory is 'conservative' if the addition of the truth predicate does not add any new theorems to the base theory.
     From: report of Volker Halbach (Axiomatic Theories of Truth [2011], 6 Df 6.6) by PG - Db (ideas)
     A reaction: Halbach presents the definition more formally, and this is my attempt at getting it into plain English. Halbach uses Peano Arithmetic as his base theory, but set theory is also sometimes used.
The Tarski Biconditional theory TB is Peano Arithmetic, plus truth, plus all Tarski bi-conditionals [Halbach]
     Full Idea: The truth theory TB (Tarski Biconditional) is all the axioms of Peano Arithmetic, including all instances of the induction schema with the truth predicate, plus all the sentences of the form T[φ] ↔ φ.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 7)
     A reaction: The biconditional formula is the famous 'snow is white' iff snow is white. The truth of the named sentence is equivalent to asserting the sentence. This is a typed theory of truth, and it is conservative over PA.
Theories of truth are 'typed' (truth can't apply to sentences containing 'true'), or 'type-free' [Halbach]
     Full Idea: I sort theories of truth into the large families of 'typed' and 'type-free'. Roughly, typed theories prohibit a truth predicate's application to sentences with occurrences of that predicate, and one cannot prove the truth of sentences containing 'true'.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], II Intro)
     A reaction: The problem sentence the typed theories are terrified of is the Liar Sentence. Typing produces a hierarchy of languages, referring down to the languages below them.
Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach]
     Full Idea: If truth is not explanatory, truth axioms should not allow proof of new theorems not involving the truth predicate. It is hence said that axiomatic truth should be 'conservative' - not implying further sentences beyond what the axioms can prove.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3)
     A reaction: [compressed]
Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach]
     Full Idea: The axiomatic approach does not presuppose that truth can be defined. Instead, a formal language is expanded by a new primitive predicate of truth, and axioms for that predicate are then laid down.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1)
     A reaction: Idea 15647 explains why Halbach thinks the definition route is no good.
3. Truth / G. Axiomatic Truth / 2. FS Truth Axioms
Friedman-Sheard is type-free Compositional Truth, with two inference rules for truth [Halbach]
     Full Idea: The Friedman-Sheard truth system FS is based on compositional theory CT. The axioms of FS are obtained by relaxing the type restriction on the CT-axioms, and adding rules inferring sentences from their truth, and vice versa.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 15)
     A reaction: The rules are called NEC and CONEC by Halbach. The system FSN is FS without the two rules.
3. Truth / G. Axiomatic Truth / 3. KF Truth Axioms
The KF theory is useful, but it is not a theory containing its own truth predicate [Halbach]
     Full Idea: KF is useful for explicating Peano arithmetic, but it certainly does not come to close to being a theory that contains its own truth predicate.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 16)
     A reaction: Since it is a type-free theory, its main philosophical aspiration was to contain its own truth predicate, so that is bad news (for philosophers).
The KF is much stronger deductively than FS, which relies on classical truth [Halbach]
     Full Idea: The Kripke-Feferman theory is relatively deductively very strong. In particular, it is much stronger than its competitor FS, which is based on a completely classical notion of truth.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 15.3)
Kripke-Feferman theory KF axiomatises Kripke fixed-points, with Strong Kleene logic with gluts [Halbach]
     Full Idea: The Kripke-Feferman theory KF is an axiomatisation of the fixed points of an operator, that is, of a Kripkean fixed-point semantics with the Strong Kleene evaluation schema with truth-value gluts.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 15.1)
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Compositional Truth CT proves generalisations, so is preferred in discussions of deflationism [Halbach]
     Full Idea: Compositional Truth CT and its variants has desirable generalisations among its logical consequences, so they seem to have ousted purely disquotational theories such as TB in the discussion on deflationism.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 8)
Some say deflationism is axioms which are conservative over the base theory [Halbach]
     Full Idea: Some authors have tried to understand the deflationist claim that truth is not a substantial notion as the claim that a satisfactory axiomatisation of truth should be conservative over the base theory.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 8)
Deflationists say truth merely serves to express infinite conjunctions [Halbach]
     Full Idea: According to many deflationists, truth serves merely the purpose of expressing infinite conjunctions.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.3)
     A reaction: That is, it asserts sentences that are too numerous to express individually. It also seems, on a deflationist view, to serve for anaphoric reference to sentences, such as 'what she just said is true'.
Deflationism says truth is a disquotation device to express generalisations, adding no new knowledge [Halbach]
     Full Idea: There are two doctrines at the core of deflationism. The first says truth is a device of disquotation used to express generalisations, and the second says truth is a thin notion that contributes nothing to our knowledge of the world
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 21)
The main problem for deflationists is they can express generalisations, but not prove them [Halbach]
     Full Idea: The main criticism that deflationist theories based on the disquotation sentences or similar axioms have to meet was raised by Tarski: the disquotation sentences do not allow one to prove generalisations.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 7)
Deflationists say truth is just for expressing infinite conjunctions or generalisations [Halbach]
     Full Idea: Deflationists do not hold that truth is completely dispensable. They claim that truth serves the purpose of expressing infinite conjunctions or generalisations.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 7)
     A reaction: It is also of obvious value as a shorthand in ordinary conversation, but rigorous accounts can paraphrase that out. 'What he said is true'. 'Pick out the true sentences from p,q,r and s' seems to mean 'affirm some of them'. What does 'affirm' mean?
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
The plausible Barcan formula implies modality in the actual world [Bird]
     Full Idea: Modality in the actual world is the import of the Barcan formula, and there are good reasons for accepting the Barcan formula.
     From: Alexander Bird (Nature's Metaphysics [2007], 1.2)
     A reaction: If you thought logic was irrelevant to metaphysics, this should make you think twice.
4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic
In Strong Kleene logic a disjunction just needs one disjunct to be true [Halbach]
     Full Idea: In Strong Kleene logic a disjunction of two sentences is true if at least one disjunct is true, even when the other disjunct lacks a truth value.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 18)
     A reaction: This sounds fine to me. 'Either I'm typing this or Homer had blue eyes' comes out true in any sensible system.
In Weak Kleene logic there are 'gaps', neither true nor false if one component lacks a truth value [Halbach]
     Full Idea: In Weak Kleene Logic, with truth-value gaps, a sentence is neither true nor false if one of its components lacks a truth value. A line of the truth table shows a gap if there is a gap anywhere in the line, and the other lines are classical.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 18)
     A reaction: This will presumably apply even if the connective is 'or', so a disjunction won't be true, even if one disjunct is true, when the other disjunct is unknown. 'Either 2+2=4 or Lot's wife was left-handed' sounds true to me. Odd.
4. Formal Logic / F. Set Theory ST / 1. Set Theory
To prove the consistency of set theory, we must go beyond set theory [Halbach]
     Full Idea: The consistency of set theory cannot be established without assumptions transcending set theory.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 2.1)
Every attempt at formal rigour uses some set theory [Halbach]
     Full Idea: Almost any subject with any formal rigour employs some set theory.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 4.1)
     A reaction: This is partly because mathematics is often seen as founded in set theory, and formal rigour tends to be mathematical in character.
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
The underestimated costs of giving up classical logic are found in mathematical reasoning [Halbach]
     Full Idea: The costs of giving up classical logic are easily underestimated, …the price being paid in terms of mathematical reasoning.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 16.2)
     A reaction: No one cares much about such costs, until you say they are 'mathematical'. Presumably this is a message to Graham Priest and his pals.
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
We can use truth instead of ontologically loaded second-order comprehension assumptions about properties [Halbach]
     Full Idea: The reduction of 2nd-order theories (of properties or sets) to axiomatic theories of truth may be conceived as a form of reductive nominalism, replacing existence assumptions (for comprehension axioms) by ontologically innocent truth assumptions.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.1)
     A reaction: I like this very much, as weeding properties out of logic (without weeding them out of the world). So-called properties in logic are too abundant, so there is a misfit with their role in science.
5. Theory of Logic / E. Structures of Logic / 7. Predicates in Logic
Instead of saying x has a property, we can say a formula is true of x - as long as we have 'true' [Halbach]
     Full Idea: Quantification over (certain) properties can be mimicked in a language with a truth predicate by quantifying over formulas. Instead of saying that Tom has the property of being a poor philosopher, we can say 'x is a poor philosopher' is true of Tom.
     From: Volker Halbach (Axiomatic Theories of Truth (2005 ver) [2005], 1.1)
     A reaction: I love this, and think it is very important. He talks of 'mimicking' properties, but I see it as philosophers mistakenly attributing properties, when actually what they were doing is asserting truths involving certain predicates.
5. Theory of Logic / E. Structures of Logic / 8. Theories in Logic
A theory is some formulae and all of their consequences [Halbach]
     Full Idea: A theory is a set of formulae closed under first-order logical consequence.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 5.1)
5. Theory of Logic / K. Features of Logics / 3. Soundness
You cannot just say all of Peano arithmetic is true, as 'true' isn't part of the system [Halbach]
     Full Idea: One cannot just accept that all the theorems of Peano arithmetic are true when one accepts Peano arithmetic as the notion of truth is not available in the language of arithmetic.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 22.1)
     A reaction: This is given as the reason why Kreisel and Levy (1968) introduced 'reflection principles', which allow you to assert whatever has been proved (with no mention of truth). (I think. The waters are closing over my head).
Normally we only endorse a theory if we believe it to be sound [Halbach]
     Full Idea: If one endorses a theory, so one might argue, one should also take it to be sound.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 22.1)
Soundness must involve truth; the soundness of PA certainly needs it [Halbach]
     Full Idea: Soundness seems to be a notion essentially involving truth. At least I do not know how to fully express the soundness of Peano arithmetic without invoking a truth predicate.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 22.1)
     A reaction: I suppose you could use some alternative locution such as 'assertible' or 'cuddly'. Intuitionists seem a bit vague about the truth end of things.
5. Theory of Logic / L. Paradox / 1. Paradox
Many new paradoxes may await us when we study interactions between frameworks [Halbach]
     Full Idea: Paradoxes that arise from interaction of predicates such as truth, necessity, knowledge, future and past truths have receive little attention. There may be many unknown paradoxes lurking when we develop frameworks with these intensional notions.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 24.2)
     A reaction: Nice. This is a wonderful pointer to new research in the analytic tradition, in which formal problems will gradually iron out our metaphysical framework.
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
The liar paradox applies truth to a negated truth (but the conditional will serve equally) [Halbach]
     Full Idea: An essential feature of the liar paradox is the application of the truth predicate to a sentence with a negated occurrence of the truth predicate, though the negation can be avoided by using the conditional.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 19.3)
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
The compactness theorem can prove nonstandard models of PA [Halbach]
     Full Idea: Nonstandard models of Peano arithmetic are models of PA that are not isomorphic to the standard model. Their existence can be established with the compactness theorem or the adequacy theorem of first-order logic.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 8.3)
The global reflection principle seems to express the soundness of Peano Arithmetic [Halbach]
     Full Idea: The global reflection principle ∀x(Sent(x) ∧ Bew[PA](x) → Tx) …seems to be the full statement of the soundness claim for Peano arithmetic, as it expresses that all theorems of Peano arithmetic are true.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 22.1)
     A reaction: That is, an extra principle must be introduced to express the soundness. PA is, of course, not complete.
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
To reduce PA to ZF, we represent the non-negative integers with von Neumann ordinals [Halbach]
     Full Idea: For the reduction of Peano Arithmetic to ZF set theory, usually the set of finite von Neumann ordinals is used to represent the non-negative integers.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 6)
     A reaction: Halbach makes it clear that this is just one mode of reduction, relative interpretability.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Set theory was liberated early from types, and recent truth-theories are exploring type-free [Halbach]
     Full Idea: While set theory was liberated much earlier from type restrictions, interest in type-free theories of truth only developed more recently.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 4)
     A reaction: Tarski's theory of truth involves types (or hierarchies).
7. Existence / A. Nature of Existence / 6. Criterion for Existence
If all existents are causally active, that excludes abstracta and causally isolated objects [Bird]
     Full Idea: If one says that 'everything that exists is causally active', that rules out abstracta (notably sets and numbers), and it rules out objects that are causally isolated.
     From: Alexander Bird (Nature's Metaphysics [2007], 5.5)
     A reaction: I like the principle. I take abstracta to be brain events, so they are causally active, within highly refined and focused brains, and if your physics is built on the notion of fields then I would think a 'causally isolated' object incoherent.
7. Existence / C. Structure of Existence / 2. Reduction
That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction [Halbach]
     Full Idea: The observation that Peano arithmetic is relatively interpretable in ZF set theory is taken by many philosophers to be a reduction of numbers to sets.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 23)
     A reaction: Nice! Being able to express something in a different language is not the same as a reduction. Back to the drawing board. What do you really mean by a reduction? If we model something, we don't 'reduce' it to the model.
7. Existence / C. Structure of Existence / 5. Supervenience / c. Significance of supervenience
If naturalism refers to supervenience, that leaves necessary entities untouched [Bird]
     Full Idea: If one's naturalistic principles are formulated in terms of supervenience, then necessary entities are left untouched.
     From: Alexander Bird (Nature's Metaphysics [2007], 5.5)
     A reaction: I take this to be part of the reason why some people like supervenience - that it leaves a pure 'space of reasons' which is unreachable from the flesh and blood inside a cranium. Personall I like the space of reasons, but I drop the 'pure'.
7. Existence / D. Theories of Reality / 4. Anti-realism
Anti-realism is more plausible about laws than about entities and theories [Bird]
     Full Idea: There is anti-realism with regard to unobservable entities and the theories that purport to mention them, but the more plausible version attaches to theories concerning what laws of nature are.
     From: Alexander Bird (Philosophy of Science [1998], Ch.4)
     A reaction: This sounds right. I certainly find anti-realism about the entities of science utterly implausible. I also doubt whether there is any such thing as a law, above and beyond the behaviour of matter. Theories float between the two.
8. Modes of Existence / B. Properties / 3. Types of Properties
There might be just one fundamental natural property [Bird]
     Full Idea: The thought that there might be just one fundamental natural property is not that strange.
     From: Alexander Bird (Nature's Metaphysics [2007], 6.3)
     A reaction: A nice variation on the Parmenides idea that only the One exists. Bird's point would refer to a possible unification of modern physics. We see, for example, the forces of electricity and of magnetism turning out to be the same force.
8. Modes of Existence / B. Properties / 6. Categorical Properties
Categorical properties are not modally fixed, but change across possible worlds [Bird]
     Full Idea: Categorical properties do not have their dispositional characters modally fixed, but may change their dispositional characters (and their causal and nomic behaviour more generally) across different worlds.
     From: Alexander Bird (Nature's Metaphysics [2007], 3.1)
     A reaction: This is the key ground for Bird's praiseworth opposition to categorical propertie. I take it to be a nonsense to call the category in which we place something a 'property' of that thing. A confusion of thought with reality.
The categoricalist idea is that a property is only individuated by being itself [Bird]
     Full Idea: In the categoricalist view, the essential properties of a natural property are limited to its essentially being itself and not some distinct property.
     From: Alexander Bird (Nature's Metaphysics [2007], 4.1)
     A reaction: He associates this view with Lewis (modern regularity view) and Armstrong (nomic necessitation), and launches a splendid attack against it. I have always laughed at the idea that 'being Socrates' was one of the properties of Socrates.
If we abstractly define a property, that doesn't mean some object could possess it [Bird]
     Full Idea: The possibility of abstract definition does not show that we have defined a property that we can know, independently of any theory, that it is physically possible for some object to possess.
     From: Alexander Bird (Nature's Metaphysics [2007], 4.2.3.1)
     A reaction: This is a naturalist resisting the idea that there is no more to a property than set-membership. I strongly agree. We need a firm notion of properties as features of the actual world; anything else should be called something like 'categorisations'.
Categoricalists take properties to be quiddities, with no essential difference between them [Bird]
     Full Idea: The categoricalist conception of properties takes them to be quiddities, which are primitive identities between fundamental qualities, having no difference with regard to their essence.
     From: Alexander Bird (Nature's Metaphysics [2007], 4.5)
     A reaction: Compare 'haecceitism' about indentity of objects, though 'quidditism' sounds even less plausible. Bird attributes this view to Lewis and Armstrong, and makes it sound well daft.
8. Modes of Existence / B. Properties / 10. Properties as Predicates
To name an abundant property is either a Fregean concept, or a simple predicate [Bird]
     Full Idea: It isn't clear what it is to name an abundant property. One might reify them, as akin to Fregean concepts, or it might be equivalent to a simple predication.
     From: Alexander Bird (Nature's Metaphysics [2007], 7.1.2)
     A reaction: 'Fregean concepts' would make them functions that purely link things (hence relational?). One suspects that people who actually treat abundant properties as part of their ontology (Lewis) are confusing natural properties with predicates.
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
Only real powers are fundamental [Bird, by Mumford/Anjum]
     Full Idea: Bird says only real powers are fundamental.
     From: report of Alexander Bird (Nature's Metaphysics [2007]) by S.Mumford/R.Lill Anjum - Getting Causes from Powers 1.5
     A reaction: They disagree, and want higher-level properties in their ontology. I'm with Bird, except that something must exist to have the powers. Powers are fundamental to all the activity of nature, and are intrinsic to the stuff which constitutes nature.
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
If all properties are potencies, and stimuli and manifestation characterise them, there is a regress [Bird]
     Full Idea: Potencies are characterized in terms of their stimulus and manifestation properties, then if potencies are the only properties then these properties are also potencies, and must be characterized by yet further properties, leading to a vicious regress.
     From: Alexander Bird (Nature's Metaphysics [2007], 1.2)
     A reaction: This is cited as the most popular objection to the dispositional account of properties.
The essence of a potency involves relations, e.g. mass, to impressed force and acceleration [Bird]
     Full Idea: The essence of a potency involves a relation to something else; if inertial mass is a potency then its essence involves a relation to a stimulus property (impressed force) and a manifestation property (acceleration).
     From: Alexander Bird (Nature's Metaphysics [2007], 5.3.3)
     A reaction: It doesn't seem quite right to say that the relations are part of the essence, if they might not occur, but some other relations might happen in their place. An essence is what makes a relation possible (like being good-looking).
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / c. Dispositions as conditional
A disposition is finkish if a time delay might mean the manifestation fizzles out [Bird]
     Full Idea: Finkish dispositions arise because the time delay between stimulus and manifestation provides an opportunity for the disposition to go out of existence and so halt the process that would bring about the manifestation.
     From: Alexander Bird (Nature's Metaphysics [2007], 2.2.3)
     A reaction: This is a problem for the conditional analysis of dispositions; there may be a disposition, but it never reaches manifestation. Bird rightly points us towards actual powers rather than dispositions that need manifestation.
A robust pot attached to a sensitive bomb is not fragile, but if struck it will easily break [Bird]
     Full Idea: If a robust iron pot is attached to a bomb with a sensitive detonator. If the pot is struck, the bomb will go off, so they counterfactual 'if the pot were struck it would break' is true, but it is not a fragile pot. This is a 'mimic' of the disposition.
     From: Alexander Bird (Nature's Metaphysics [2007], 2.2.5.1)
     A reaction: A very nice example, showing that a true disposition would have to be an internal feature (a power) of the pot itself, not a mere disposition to behave. The problem is these pesky empiricists, who want to reduce it all to what is observable.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / d. Dispositions as occurrent
Megarian actualists deny unmanifested dispositions [Bird]
     Full Idea: The Megarian actualist denies that a disposition can exist without being manifested.
     From: Alexander Bird (Nature's Metaphysics [2007], 5.4)
     A reaction: I agree with Bird that this extreme realism seems wrong. As he puts it (p.109), "unrealized possibilities must be part of the actual world". This commitment is beginning to change my understanding of the world I am looking at.
8. Modes of Existence / D. Universals / 3. Instantiated Universals
Why should a universal's existence depend on instantiation in an existing particular? [Bird]
     Full Idea: An instantiation condition seems to be a failure of nerve as regards realism about universals. If universals really are entities in their own right, why should their existence depend upon a relationship with existing particulars?
     From: Alexander Bird (Nature's Metaphysics [2007], 3.2.2)
     A reaction: I like this challenge, which seems to leave fans of universals no option but full-blown Platonism, which most of them recognise as being deeply implausible.
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
Resemblance itself needs explanation, presumably in terms of something held in common [Bird]
     Full Idea: The realist view of resemblance nominalism is that it is resemblance that needs explaining. When there is resemblance it is natural to want to explain it, in terms of something held in common. Explanations end somewhere, but not with resemblance.
     From: Alexander Bird (Nature's Metaphysics [2007], 2.1.2)
     A reaction: I smell a regress. If a knife and a razor resemble because they share sharpness, you have to see that the sharp phenomenon falls within the category of 'sharpness' before you can make the connection, which is spotting its similarity.
10. Modality / A. Necessity / 2. Nature of Necessity
Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach]
     Full Idea: Should necessity be treated as a predicate rather than (as in modal logic) as a sentential operator? It is odd to assign different status to necessity and truth, hampering their interaction. That all necessities are true can't be expressed by an operator.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 24.2)
     A reaction: [compressed] Halbach and Horsten consistently treat truth as a predicate, but maybe truth is an operator. Making necessity a predicate and not an operator would be a huge upheaval in the world of modal logic. Nice move!
10. Modality / A. Necessity / 3. Types of Necessity
If the laws necessarily imply p, that doesn't give a new 'nomological' necessity [Bird]
     Full Idea: It does not add to the kinds of necessity to say that p is 'nomologically necessary' iff (the laws of nature → p) is metaphysically necessary. That trick of construction could be pulled for 'feline necessity' (true in all worlds that contain cats).
     From: Alexander Bird (Nature's Metaphysics [2007], 3.1.2)
     A reaction: I love it! Bird seems to think that the only necessity is 'metaphysical' necessity, true in all possible worlds, and he is right. The question arises in modal logic, though, of the accessibility between worlds (which might give degrees of necessity?).
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessitation is not a kind of necessity; George Orwell not being Eric Blair is not a real possibility [Bird]
     Full Idea: I do not regard logical necessitation as a kind of necessity. It is logically possible that George Orwell is not Eric Blair, but in what sense is this any kind of possibility? It arises from having two names, but that confers no genuine possibility.
     From: Alexander Bird (Nature's Metaphysics [2007], 3.1.2)
     A reaction: How refreshing. All kinds of concepts like this are just accepted by philosophers as obvious, until someone challenges them. The whole undergrowth of modal thinking needs a good flamethrower taken to it.
10. Modality / B. Possibility / 6. Probability
Subjective probability measures personal beliefs; objective probability measures the chance of an event happening [Bird]
     Full Idea: Subjective probability measures a person's strength of belief in the truth of a proposition; objective probability concerns the chance a certain sort of event has of happening, independently of whether anyone thinks it is likely to occur or not.
     From: Alexander Bird (Philosophy of Science [1998], Ch.6)
     A reaction: The challenge to the second one is that God would know for certain whether a meteor will hit the Earth next week. The impact looks like 'bad luck' to us, but necessary to one who really knows.
Objective probability of tails measures the bias of the coin, not our beliefs about it [Bird]
     Full Idea: In tossing a coin, the objective probability of tails is a measure of the bias of the coin; the bias and the probability are objective features of the coin, like its mass and shape; these properties have nothing to do with our beliefs about the coin.
     From: Alexander Bird (Philosophy of Science [1998], Ch.6)
     A reaction: Despite my reservation that God would not seem to be very interested in the probabilities of coin-tossing, since he knows each outcome with certaintly, this is fairly convincing. God might say that the coin has a 'three-to-two bias'.
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
Empiricist saw imaginability and possibility as close, but now they seem remote [Bird]
     Full Idea: Whereas the link between imaginability and possibility was once held, under the influence of empiricism, to be close, it is now widely held to be very remote.
     From: Alexander Bird (Nature's Metaphysics [2007], 8)
     A reaction: Tim Williamson nicely argues the opposite - that assessment of possibility is an adjunct of our ability to think counterfactually, which is precisely an operation of the imagination. Big error is possible, but how else could we do it?
10. Modality / E. Possible worlds / 3. Transworld Objects / d. Haecceitism
Haecceitism says identity is independent of qualities and without essence [Bird]
     Full Idea: The core of haecceitism is the view that the transworld identity of particulars does not supervene on their qualitative features. ...The simplest expression of it is that particulars lack essential properties.
     From: Alexander Bird (Nature's Metaphysics [2007], 4.2.1)
     A reaction: This seems to be something the 'bare substratum' account of substance (associated with Locke). You are left with the difficulty of how to individuate an instance of the haecceity, as opposed to the bundle of properties attached to it.
13. Knowledge Criteria / A. Justification Problems / 1. Justification / b. Need for justification
Many philosophers rate justification as a more important concept than knowledge [Bird]
     Full Idea: Many philosophers take the notion of justification to be more important or more basic than the concept of knowledge.
     From: Alexander Bird (Philosophy of Science [1998], Ch.7)
     A reaction: Intriguing. Given the obvious social and conventional element in 'knowledge' ("do we agree that the candidate really knows the answer?"), justification may well be closer to where the real action is. 'Logos', after all, is at the heart of philosophy.
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / b. Pro-coherentism
As science investigates more phenomena, the theories it needs decreases [Bird]
     Full Idea: A remarkable fact about modern science is that as the number of phenomena which science has investigated has grown, the number of theories needed to explain them has decreased.
     From: Alexander Bird (Philosophy of Science [1998], Ch.4)
     A reaction: This rebuts the idea that theories are probably false because we are unlikely to have thought of the right one (Idea 6784). More data suggests more theories, yet we end up with fewer theories. Why is simplification of theories possible?
14. Science / A. Basis of Science / 1. Observation
If theories need observation, and observations need theories, how do we start? [Bird]
     Full Idea: If we cannot know the truth of theories without observation, and we cannot know the truth of observations without theories, where do we start?
     From: Alexander Bird (Philosophy of Science [1998], Ch.5)
     A reaction: See Idea 6793. You make a few observations, under the illusion that they are objective, then formulate a promising theory, then go back and deconstruct the observations, then tighten up the theory, and so on.
14. Science / A. Basis of Science / 4. Prediction
Explanation predicts after the event; prediction explains before the event [Bird]
     Full Idea: Explanation is prediction after the event and prediction is explanation before the event.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: A nice slogan, fitting Hempel's 'covering law' view of explanation. It doesn't seem quite right, because explanations and predictions are couched in very different language. Prediction implies an explanation; explanation implies a prediction.
14. Science / B. Scientific Theories / 1. Scientific Theory
Relativity ousted Newtonian mechanics despite a loss of simplicity [Bird]
     Full Idea: The theories of relativity ousted Newtonian mechanics despite a loss of simplicity.
     From: Alexander Bird (Philosophy of Science [1998])
     A reaction: This nicely demonstrates that simplicity is not essential, even if it is desirable. The point applies to the use of Ockham's Razor (Idea 6806), and to Hume's objection to miracles (Idea 2227), where strange unnatural events may be the truth.
Realists say their theories involve truth and the existence of their phenomena [Bird]
     Full Idea: A realist says of their theories that they can be evaluated according to truth, they aim at truth, their success favours their truth, their unobserved entities probably exist, and they would explain the observable phenomena.
     From: Alexander Bird (Philosophy of Science [1998], Ch.4)
     A reaction: This seems to me to be the only sensible attitude towards scientific theories, even if they do become confusing down at the level of quantum theory. Theories aim to be true explanations.
There is no agreement on scientific method - because there is no such thing [Bird]
     Full Idea: I find little concurrence as to what scientific method might actually be - the reason being, I conclude, that there is no such thing.
     From: Alexander Bird (Philosophy of Science [1998], Ch.8)
     A reaction: I take the essence of science to be two things: first, becoming very fussy about empirical evidence; second, setting up controlled conditions to get at the evidence that seems to be needed. I agree that there seems to be no distinctive way of thinking.
14. Science / B. Scientific Theories / 3. Instrumentalism
Instrumentalists regard theories as tools for prediction, with truth being irrelevant [Bird]
     Full Idea: Instrumentalism is so called because it regards theories not as attempts to describe or explain the world, but as instruments for making predictions; for the instrumentalist, asking about the truth of a theory is a conceptual mistake.
     From: Alexander Bird (Philosophy of Science [1998], Ch.4)
     A reaction: It cannot be denied that theories are used to make predictions, and there is nothing wrong with being solely interested in predictions. I cannot make head or tail of the idea that truth is irrelevant. Why is a given theory so successful?
14. Science / C. Induction / 2. Aims of Induction
Induction is inference to the best explanation, where the explanation is a law [Bird]
     Full Idea: Induction can be seen as inference to the best explanation, where the explanation is a law.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: I like this. I increasingly think of explanation as central to rational thought, as the key route for empiricists to go beyond their immediate and verifiable experience. Laws can be probabilistic.
14. Science / C. Induction / 3. Limits of Induction
If Hume is right about induction, there is no scientific knowledge [Bird]
     Full Idea: If Hume is right about induction then there is no scientific knowledge.
     From: Alexander Bird (Philosophy of Science [1998], Ch.5)
     A reaction: The first step is to recognise that induction is not deductively valid, but that does not make it irrational. If something happens five times, get ready for the sixth. If we discover the necessary features of nature, we can predict the future.
Anything justifying inferences from observed to unobserved must itself do that [Bird]
     Full Idea: Whatever could do the job of justifying an inference from the observed to the unobserved must itself be an inference from the observed to the unobserved.
     From: Alexander Bird (Philosophy of Science [1998], Ch.5)
     A reaction: We must first accept that the unobserved might not be like the observed, no matter how much regularity we have, so it can't possibly be a logical 'inference'. Essences generate regularities, but non-essences may not.
14. Science / C. Induction / 5. Paradoxes of Induction / a. Grue problem
Any conclusion can be drawn from an induction, if we use grue-like predicates [Bird]
     Full Idea: It looks as if any claim about the future can be made to be a conclusion of an inductive argument from any premises about the past, as long as we use a strange enough grue-like predicate.
     From: Alexander Bird (Philosophy of Science [1998], Intro)
     A reaction: So don't use strange grue-like predicates. If all our predicates randomly changed their reference each day, we would be unable to talk to one another at all. Emeralds don't change their colour-properties, so why change the predicates that refer to them?
Several months of observing beech trees supports the deciduous and evergreen hypotheses [Bird]
     Full Idea: If someone were to observe beech trees every day over one summer they would have evidence that seems to support both the hypothesis that beech trees are deciduous and the hypothesis that they are evergreens.
     From: Alexander Bird (Philosophy of Science [1998], Intro)
     A reaction: Bird offers this to anyone who (like me) is tempted to dismiss the 'grue' problem as ridiculous. Obviously he is right; 'deciduous' works like 'grue'. But we invented the predicate 'deciduous' to match an observed property.
We normally learn natural kinds from laws, but Goodman shows laws require prior natural kinds [Bird]
     Full Idea: We know what natural kinds there are by seeing which properties appear in the laws of nature. But one lesson of Goodman's problem is that we cannot identify the laws of nature without some prior identification of natural kinds.
     From: Alexander Bird (Philosophy of Science [1998], Ch.7)
     A reaction: For Goodman's problem, see Idea 4783. The essentialist view is that the natural kinds come first, and the so-called 'laws' are just regularities in events that arise from the interaction of stable natural kinds. (Keep predicates and properties separate).
14. Science / C. Induction / 6. Bayes's Theorem
Bayesianism claims to find rationality and truth in induction, and show how science works [Bird]
     Full Idea: Keen supporters of Bayesianism say it can show how induction is rational and can lead to truth, and it can reveal the underlying structure of actual scientific reasoning.
     From: Alexander Bird (Philosophy of Science [1998], Ch.6)
     A reaction: See Idea 2798 for Bayes' Theorem. I find it intuitively implausible that our feeling for probabilities could be reduced to precise numbers, given the subjective nature of the numbers we put into the equation.
14. Science / D. Explanation / 1. Explanation / a. Explanation
The objective component of explanations is the things that must exist for the explanation [Bird]
     Full Idea: There is an 'objective', non-epistemic component to explanations, consisting of the things that must exist for A to be able to explain B, and the relations those things have to one another.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: There seems to be some question-begging here, in that you have to decide what explanation you are after before you can decide which existences are of interest. There are objective facts, though, about what causally links to what.
We talk both of 'people' explaining things, and of 'facts' explaining things [Bird]
     Full Idea: We talk both of 'people' explaining things, and of 'facts' explaining things.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: An important point, and it is the job of philosophers to pull the two apart. How we talk does not necessarily show how it is. The concept of explanation is irrelevant in a universe containing no minds, or one containing only God. People seek the facts.
14. Science / D. Explanation / 1. Explanation / b. Aims of explanation
We can't reject all explanations because of a regress; inexplicable A can still explain B [Bird]
     Full Idea: Some regard the potential regress of explanations as a reason to think that the very idea of explanation is illusory. This is a fallacy; it is not a necessary condition on A's explaining B that we have an explanation for A also.
     From: Alexander Bird (Nature's Metaphysics [2007], 3.2.4)
     A reaction: True, though to say 'B is explained by A, but A is totally baffling' is not the account we are dreaming of. And the explanation would certainly fail if we could say nothing at all about A, apart from naming it.
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
Explanations are causal, nomic, psychological, psychoanalytic, Darwinian or functional [Bird]
     Full Idea: Explanations can be classified as causal, nomic, psychological, psychoanalytic, Darwinian and functional.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: These could be subdivided, perhaps according to different types of cause. Personally, being a reductionist (like David Lewis, see Idea 3989), I suspect that all of these explanations could be reduced to causation. Essences explain causes.
14. Science / D. Explanation / 2. Types of Explanation / b. Contrastive explanations
Contrastive explanations say why one thing happened but not another [Bird]
     Full Idea: A 'contrastive explanation' explains why one thing happened but not another.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: If I explain why the ship sank, is this contrastive, or just causal, or both? Am I explaining why it sank rather than turned into a giraffe? An interesting concept, but I can't see myself making use of it.
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
'Covering law' explanations only work if no other explanations are to be found [Bird]
     Full Idea: The fact that something fits the 'covering law' model of explanation is no guarantee that it is an explanation, for that depends on what other explanations are there to be found.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: He gives Achinstein's example of a poisoned man who is run over by a bus. It has to be a basic requirement of explanations that they are the 'best', and not just something that fits a formula.
Livers always accompany hearts, but they don't explain hearts [Bird]
     Full Idea: All animals with a liver also have a heart; so we can deduce from this plus the existence of Fido's liver that he also has a heart, but his liver does not explain why he has a heart.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: This is a counterexample to Hempel's deductive-nomological view of explanation. It seems a fairly decisive refutation of any attempt to give a simple rule for explaining things. Different types of explanation compete, and there is a subjective element.
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?
14. Science / D. Explanation / 2. Types of Explanation / l. Probabilistic explanations
Probabilistic-statistical explanations don't entail the explanandum, but makes it more likely [Bird]
     Full Idea: The probabilistic-statistical view of explanation (also called inductive-statistical explantion) is similar to deductive-nomological explanation, but instead of entailing the explanandum a probabilistic-statistical explantion makes it very likely.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: If people have umbrellas up, does that explain rain? Does the presence of a psychopath in the audience explain why I don't go to a rock concert? Still, it has a point.
An operation might reduce the probability of death, yet explain a death [Bird]
     Full Idea: An operation for cancer might lead to a patient's death, and so it explains the patient's death while at the same time reducing the probability of death.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: This attacks Hempel's 'covering law' approach. Increasing probability of something clearly does not necessarily explain it, though it often will. Feeding you contaminated food will increase the probability of your death, and may cause it.
14. Science / D. Explanation / 3. Best Explanation / a. Best explanation
Inference to the Best Explanation is done with facts, so it has to be realist [Bird]
     Full Idea: Explanation of a fact is some other fact or set of facts. And so Inference to the Best Explanation is inference to facts; someone who employs it cannot but take a realist attitude to a theory which is preferred on these grounds.
     From: Alexander Bird (Philosophy of Science [1998], Ch.4)
     A reaction: So my personal commitment to abduction is entailed by my realism, and my realism is entailed by my belief in the possibility of abduction. We can't explain the properties of a table just by referring to our experiences of tables.
14. Science / D. Explanation / 3. Best Explanation / c. Against best explanation
Maybe bad explanations are the true ones, in this messy world [Bird]
     Full Idea: It is objected to 'best explanation' that this may well not be the best of all possible worlds - so why think that the best explanation is true? Maybe bad (complicated, unsystematic and weak) explanations are true.
     From: Alexander Bird (Philosophy of Science [1998], Ch.4)
     A reaction: The only rebuttal of this objection to best explanation seems to be a priori. It would just seem an odd situation if very simple explanations fitted the facts and yet were false, like the points on a graph being a straight line by pure coincidence.
Which explanation is 'best' is bound to be subjective, and no guide to truth [Bird]
     Full Idea: It is objected to 'best explanation' that beauty is in the eye of the beholder - the goodness of possible explanations is subjective, and so the choice of best explanation is also subjective, and hence not a suitable guide to truth.
     From: Alexander Bird (Philosophy of Science [1998], Ch.4)
     A reaction: Explanation is indeed dependent both on the knowledge of the person involved, and on their interests. That doesn't, though, mean that you can choose any old explanation. Causal networks are features of the world.
14. Science / D. Explanation / 4. Explanation Doubts / a. Explanation as pragmatic
Maybe explanation is so subjective that it cannot be a part of science [Bird]
     Full Idea: Some philosophers have thought that explanation is hopelessly subjective, so subjective even that it is should have no part in proper science.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: God requires no explanations, and children require many. If fundamental explanations are causal, then laying bare the causal chains is the explanation, whether you want it or not. God knows all the explanations. See Idea 6752.
15. Nature of Minds / C. Capacities of Minds / 9. Perceiving Causation
Causation seems to be an innate concept (or acquired very early) [Bird]
     Full Idea: There is evidence that the concept of causation is innate, or that we are primed to acquire it very early in life, within months at most.
     From: Alexander Bird (Causation and the Manifestation of Powers [2010], p.167)
     A reaction: Bird doesn't give any references. This is important for our understanding of induction. Creatures seem to learn from a single instance, rather than waiting for habit to be ingrained by many instances. They must infer a cause.
19. Language / D. Propositions / 4. Mental Propositions
We need propositions to ascribe the same beliefs to people with different languages [Halbach]
     Full Idea: Being able to ascribe the same proposition as a belief to persons who do not have a common language seems to be one of the main reasons to employ propositions.
     From: Volker Halbach (Axiomatic Theories of Truth [2011], 2)
     A reaction: Propositions concern beliefs, as well as sentence meanings. I would want to say that a dog and I could believe the same thing, and that is a non-linguistic reason to believe in propositions. Maybe 'translation' cuts out the proposition middleman?
26. Natural Theory / B. Natural Kinds / 1. Natural Kinds
Natural kinds are those that we use in induction [Bird]
     Full Idea: Natural kinds are the kinds one should make use of in inductive inference (if that is explanation which leads to laws).
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: The problem with this is that it is epistemological rather than ontological. In induction we use superficial resemblences that are immediately obvious, whereas the nature of kinds can be buried deep in the chemistry or physics.
Rubies and sapphires are both corundum, with traces of metals varying their colours [Bird]
     Full Idea: Both rubies (valuable) and sapphires (less valuable) are corundum (Al2O3), differing only in their colours, for which traces of iron, titanium and chomium are responsible.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: A nice example which illustrates how natural kinds determined by nominal essence could be drastically different from those suggested by real essence. It certainly suggests that corundum might be a natural kind, but ruby isn't.
Tin is not one natural kind, but appears to be 21, depending on isotope [Bird]
     Full Idea: If real essences are decided by microstructure, then what we call the element tin is not a natural kind, but a mixture of 21 different kinds, one for each isotope. There also exist two different allotropes of tin - white tin and grey tin.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: This example vividly brings out the difficulties of the Kripke-Putnam view. If natural kinds 'overlap', then there would be a very extensive overlap among the 21 isotopes of tin.
Membership of a purely random collection cannot be used as an explanation [Bird]
     Full Idea: One might randomly collect diverse things and give the collection a name, but one would not expect it to explain anything to say that a certain object belonged to this collection.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: This is in support of Bird's view that natural kinds are formulated because of their explanatory role. There is, though, an undeniable subjective aspect to explanation, in that explanations arise from the ignorance and interests of persons.
Natural kinds may overlap, or be sub-kinds of one another [Bird]
     Full Idea: It seems clear that in some cases one natural kind may be a subkind of another, while in other cases natural kinds may overlap without one being the subkind of another.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: Given the enormous difficulty of pinpointing natural kinds (e.g. Idea 6768), it is hard to know whether the comment is correct or not. Ellis says natural kinds come 'in hierarchies', which would make subkinds normal, but overlapping unlikely.
26. Natural Theory / B. Natural Kinds / 2. Defining Kinds
If F is a universal appearing in a natural law, then Fs form a natural kind [Bird]
     Full Idea: The proposal is that if F is a universal appearing in some natural law, then Fs form a natural kind.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: Such proposals always invite the question 'What is it about F that enables it to be a universal in a natural law?' Nothing can be ultimately defined simply by its role. The character (essence, even) of the thing makes the role possible.
26. Natural Theory / B. Natural Kinds / 3. Knowing Kinds
In the Kripke-Putnam view only nuclear physicists can know natural kinds [Bird]
     Full Idea: In the Kripke-Putnam view, it is very difficult for anyone except nuclear physicists to pick out natural kinds, since everything else is made out of compounds of different isotopes.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: The concept of a rigid 'natural kind' does not have to be sacred. Tin might be considered a natural kind, despite having 21 isotopes. What matters is protons, not the neutrons.
Darwinism suggests that we should have a native ability to detect natural kinds [Bird]
     Full Idea: Creatures that are able to recognise natural kinds and laws have a selective advantage, so Darwinism suggests that we should have some native ability to detect natural kinds.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: This seems right, but it makes 'natural kind' a rather instrumental concept, relative to our interests. True natural kinds cut across our interests, as when we discover by anatomy that whales are not fish, or that rubies and sapphires are both corundum.
26. Natural Theory / B. Natural Kinds / 5. Reference to Natural Kinds
Nominal essence of a natural kind is the features that make it fit its name [Bird]
     Full Idea: The nominal essence of a natural kind K consists of those features a thing must have to deserve the name 'a K' by virtue of the meaning of that name.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: Some people think 'nominal essence' is the only essence there is, which would make it relative to human languages. The rival view is that there are 'real essences'. I favour the latter view.
Jadeite and nephrite are superficially identical, but have different composition [Bird]
     Full Idea: There might be more than one natural kind that shares the same superficial features, …jade, for example, has two forms, jadeite and nephrite, which are similar in superficial properties, but have different chemical composition and structure.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: It might be questioned whether jadeite and nephrite really are natural kinds, either together or separately.
Reference to scientific terms is by explanatory role, not by descriptions [Bird]
     Full Idea: I propose that reference to scientific terms, such as natural kinds and theoretical terms, is not determined by a sense or description attached to the term, but by its explanatory role.
     From: Alexander Bird (Philosophy of Science [1998], Ch.8)
     A reaction: He gives the example of an electron, which had the same role in electrical theory, despite changes in understanding its nature. One might talk of its 'natural' (causal) role, rather than its 'explanatory' role (which implies a human viewpoint).
26. Natural Theory / C. Causation / 2. Types of cause
The dispositional account explains causation, as stimulation and manifestation of dispositions [Bird]
     Full Idea: The analysis of causation in terms of dispositions provides no conceptual reduction, but it does provide insight into the metaphysics of causation. We then know what causation is - it is the stimulation and manifestation of a disposition.
     From: Alexander Bird (Causation and the Manifestation of Powers [2010], p.167)
     A reaction: I would say that it offers the essence of causation, by giving a basic explanation of it. See Mumford/Lill Anjum on this.
26. Natural Theory / C. Causation / 4. Naturalised causation
We should explain causation by powers, not powers by causation [Bird]
     Full Idea: The notion of 'causal power' is not to be analysed in terms of causation; if anything, the relationship is the reverse.
     From: Alexander Bird (Nature's Metaphysics [2007], 4.2.1 n71)
     A reaction: It is a popular view these days to take causation as basic (as opposed to the counterfactual account), but I prefer this view. If anything is basic in nature, it is the dynamic force in the engine room, which is the active powers of substances.
26. Natural Theory / C. Causation / 9. General Causation / b. Nomological causation
Laws are more fundamental in science than causes, and laws will explain causes [Bird]
     Full Idea: I think laws are fundamental and where there is a cause there is always a set of laws that encompasses the cause; identifying a cause will never be the final word in an scientific investigation, but will be open to supplementation by the underlying law.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: I think this is wrong. I would say (from the essentialist angle) that essences have causes, and the laws are the regularities that are caused by the essences. If laws are the lowest level of explanation, why these laws and not others? God?
Singularism about causes is wrong, as the universals involved imply laws [Bird]
     Full Idea: While singularists about causation might think that a particular has its causal powers independently of law, it is difficult to see how a universal could have or confer causal powers without generating what we would naturally think of as a law.
     From: Alexander Bird (Nature's Metaphysics [2007], 4.2.1 n71)
     A reaction: This is a middle road between the purely singularist account (Anscombe) and the fully nomological account. We might say that a caused event will be 'involved in law-like behaviour', without attributing the cause to a law.
26. Natural Theory / C. Causation / 9. General Causation / c. Counterfactual causation
The counterfactual approach makes no distinction between cause and pre-condition [Bird]
     Full Idea: The counterfactual approach makes no distinction between cause and condition, ...but when the smoke sets off the fire alarm, the smoke is the cause, whereas the presence of the alarm is just the condition.
     From: Alexander Bird (Causation and the Manifestation of Powers [2010], p.162)
     A reaction: Bird defends the idea that causes are what stimulate dispositions to act.
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
Newton's laws cannot be confirmed individually, but only in combinations [Bird]
     Full Idea: None of Newton's laws individually records anything that can be observed; it is only from combinations of Newton's laws that we can derive the measurable motions of bodies.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: This certainly scuppers any traditional positivist approach to how we confirm laws of nature. It invites the possibility that a different combination might fit the same observations. Experiments attempt to isolate laws.
Parapsychology is mere speculation, because it offers no mechanisms for its working [Bird]
     Full Idea: Wegener's theory of continental drift was only accepted when the theory of plate tectonics was developed, providing a mechanism. While some correlations exist for parapsychology, lack of plausible mechanisms leaves it as speculation.
     From: Alexander Bird (Philosophy of Science [1998], Ch.2)
     A reaction: But parapsychology is not even on a par with Wegener's speculation, because his was consistent with known physical laws, whereas parapsychology flatly contradicts them. The so-called correlations are also not properly established.
Existence requires laws, as inertia or gravity are needed for mass or matter [Bird]
     Full Idea: I suspect that what we mean by 'mass' and 'matter' depends on our identifying the existence of laws of inertia and gravity; hence the idea of a world without laws is incoherent, for there to be anything at all there must be some laws and some kinds.
     From: Alexander Bird (Philosophy of Science [1998], Ch.3)
     A reaction: I find this counterintuitive. Reasonably stable existence requires something reasonably like laws. We only understand the physical world because we interact with it. But neither of those is remotely as strong as Bird's claim.
Laws are explanatory relationships of things, which supervene on their essences [Bird]
     Full Idea: The laws of a domain are the fundamental, general explanatory relationships between kinds, quantities, and qualities of that domain, that supervene upon the essential natures of those things.
     From: Alexander Bird (Nature's Metaphysics [2007], 10.1)
     A reaction: This is the scientific essentialist view of laws [see entries there, in 'Laws of Nature']. There seems uncertainty between 'kinds' and 'qualities' (with 'quantities' looking like a category mistake). I vote, with Ellis, for natural kinds as the basis.
26. Natural Theory / D. Laws of Nature / 2. Types of Laws
Laws are either disposition regularities, or relations between properties [Bird]
     Full Idea: Instead of viewing laws as regular relationships between dispositional properties and stimulus-manifestation, they can be conceived of as a relation between properties.
     From: Alexander Bird (Nature's Metaphysics [2007], 3.4)
     A reaction: Bird offers these as the two main views, with the first coming from scientific essentialism, and the second from Armstrong's account of universals. Personally I favour the first, but Bird suggests that powers give the best support for both views.
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
'All uranium lumps are small' is a law, but 'all gold lumps are small' is not [Bird]
     Full Idea: 'Uranium lumps have mass of less than 1000 kg' is a law, but 'gold lumps have mass of less than 1000kg' is not a law.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: A nice example. Essentialists talk about the nature of the substances; regularity theorists prefer to talk of nested or connected regularities (e.g. about explosions). In induction, how do you decide what your duty requires you to observe?
There can be remarkable uniformities in nature that are purely coincidental [Bird]
     Full Idea: Bode's non-law (of 1772, about the gaps between the planets) shows that there can be remarkable uniformities in nature that are purely coincidental.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: If Bode's law really were confirmed, even for asteroids and newly discovered planets, it might suggest that an explanation really is required, and there is some underlying cause. How likely is the coincidence? Perhaps we have no way of telling.
A law might have no instances, if it was about things that only exist momentarily [Bird]
     Full Idea: A law might have no instances at all; for example, about the chemical and electrical behaviour of the transuranic elements, which only exist briefly in laboratories.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: Nice example. We need to distinguish, though, (as Bird reminds us) between laws and theories. We have no theories in this area, but there are counterfactual truths about what the transuranic elements would do in certain circumstances.
If laws are just instances, the law should either have gaps, or join the instances arbitrarily [Bird]
     Full Idea: For the simple regularity theorist, the function ought to be a gappy one, leaving out values not actually instantiated; …one function would fit the actual points on the graph as well as any other.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: The 'simple' theorist says there is nothing more to a law than its instances. Clearly Bird is right; if the points line up, we join them with a straight line, making counterfactual assumptions about points which were not actually observed.
Where is the regularity in a law predicting nuclear decay? [Bird]
     Full Idea: If a law of nuclear physics says that nuclei of a certain kind have a probability p of decaying within time t, what is the regularity here?
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: Hume gives an answer, in terms of regularities observed among previous instances. Nevertheless the figure p given in the law does not itself have any instances, so the law is predicting something that may never have actually happened before.
Laws cannot explain instances if they are regularities, as something can't explain itself [Bird]
     Full Idea: It can be objected that laws cannot do the job of explaining their instances if they are merely regularities, ...because something cannot explain itself.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: A nice point. The objection assumes that a law should explain things, rather than just describing them. I take the model to be smoking-and-cancer; the statistics describe what is happening, but only lung biochemistry will explain it.
There may be many laws, each with only a few instances [Bird]
     Full Idea: It might be that there is a large number of laws each of which has only a small number of instances.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: This is a problem for the Ramsey-Lewis view (Idea 6745) that the laws of nature are a simple, powerful and coherent system. We must be cautious about bringing a priori principles like Ockham's Razor (Idea 3667) to bear on the laws of nature.
That other diamonds are hard does not explain why this one is [Bird]
     Full Idea: The fact that some other diamonds are hard does not explain why this diamond is hard.
     From: Alexander Bird (Nature's Metaphysics [2007], 4.3.2)
     A reaction: A very nice aphorism! It pinpoints the whole error of trying to explain the behaviour of the world by citing laws. Why should this item obey that law? Bird prefers 'powers', and so do I.
Similar appearance of siblings is a regularity, but shared parents is what links them [Bird]
     Full Idea: There may be a regularity of siblings looking similar, but the tie that binds them is not their similarity, but rather their being born of the same parents.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: A nice objection to the regularity view. Regularities, as so often in philosophy (e.g. Idea 1364), may be the evidence or test for a law, rather than the law itself, which requires causal mechanisms, ultimately based (I think) in essences.
We can only infer a true regularity if something binds the instances together [Bird]
     Full Idea: We cannot infer a regularity from its instances unless there is something stronger than the regularity itself binding the instances together.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: Spells out the implication of the example in Idea 6748. The reply to this criticism would be that no account can possibly be given of the 'something stronger' than further regularities, at a lower level (e.g. in the physics).
If we only infer laws from regularities among observations, we can't infer unobservable entities. [Bird]
     Full Idea: If the naïve inductivist says we should see well-established regularities among our observations, and take that to be the law or causal connection…this will not help us to infer the existence of unobservable entities.
     From: Alexander Bird (Philosophy of Science [1998], Ch.8)
     A reaction: The obvious solution to this difficulty is an appeal to 'best explanation'. Bird is obviously right that we couldn't survive in the world, let alone do science, if we only acted on what we had actually observed (e.g. many bodies, but not the poison).
Accidental regularities are not laws, and an apparent regularity may not be actual [Bird]
     Full Idea: Many actual regularities are not laws (accidental regularities), and many perceived regularities are not actual ones (a summer's worth of observing green leaves).
     From: Alexander Bird (Philosophy of Science [1998], Ch.8)
     A reaction: These problems are not sufficient to refute the regularity view of laws. Accidental regularities can only be short-lived, and perceived regularities support laws without clinching them. There is an awful lot of regularity behind laws concerning gravity.
Dispositional essentialism says laws (and laws about laws) are guaranteed regularities [Bird]
     Full Idea: For the regularity version of dispositional essentialism about laws, laws are those regularities whose truth is guaranteed by the essential dispositional nature of one or more of the constituents. Regularities that supervene on such laws are also laws.
     From: Alexander Bird (Nature's Metaphysics [2007], 3.1.2)
     A reaction: Even if you accept necessary behaviour resulting from essential dispositions, you still need to distinguish the important regularities from the accidental ones, so the word 'guarantee' is helpful, even if it raises lots of difficulties.
26. Natural Theory / D. Laws of Nature / 4. Regularities / b. Best system theory
A regularity is only a law if it is part of a complete system which is simple and strong [Bird]
     Full Idea: The systematic (Ramsey-Lewis) regularity theory says that a regularity is a law of nature if and only if it appears as a theorem or axiom in that true deductive system which achieves a best combination of simplicity and strength.
     From: Alexander Bird (Philosophy of Science [1998], Ch.1)
     A reaction: Personally I don't accept the regularity view of laws, but this looks like the best account anyone has come up with. Individual bunches of regularities can't add up to or demonstrate a law, but coherence with all regularities might do it.
With strange enough predicates, anything could be made out to be a regularity [Bird]
     Full Idea: We learned from Goodman's problem that with strange enough predicates anything could be made out to be a regularity.
     From: Alexander Bird (Philosophy of Science [1998], Ch.8)
     A reaction: For Goodman's problem, see Idea 4783. The point, as I see it, is that while predicates can be applied arbitrarily (because they are just linguistic), properties cannot, because they are features of the world. Emeralds are green.
26. Natural Theory / D. Laws of Nature / 5. Laws from Universals
Laws cannot offer unified explanations if they don't involve universals [Bird]
     Full Idea: Laws, or what flow from them, are supposed to provide a unified explanation of the behaviours of particulars. Without universals the explanation of the behaviours of things lacks the required unity.
     From: Alexander Bird (Nature's Metaphysics [2007], 2.1.2)
     A reaction: Sounds a bit question-begging? Gravity seems fairly unified, whereas the frequency of London buses doesn't. Maybe I could unify bus-behaviour by positing a few new universals? The unity should first be in the phenomena, not in the explanation.
If the universals for laws must be instantiated, a vanishing particular could destroy a law [Bird]
     Full Idea: If universals exist only where and when they are instantiated, this make serious trouble for the universals view of laws. It would be most odd if a particular, merely by changing its properties, could cause a law to go out of existence.
     From: Alexander Bird (Nature's Metaphysics [2007], 3.2.2)
     A reaction: This sounds conclusive. He notes that this is probably why Armstrong does not adopt this view (though Lowe seems to favour it). Could there be a possible property (and concomitant law) which was never ever instantiated?
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / b. Scientific necessity
Salt necessarily dissolves in water, because of the law which makes the existence of salt possible [Bird]
     Full Idea: We cannot have a world where it is true both that salt exists (which requires Coulomb's Law to be true), and that it fails to dissolve in water (which requires Coulomb's Law to be false). So the dissolving is necessary even if the Law is contingent.
     From: Alexander Bird (Nature's Metaphysics [2007], 8.2)
     A reaction: Excellent. It is just like the bonfire on the Moon (imaginable through ignorance, but impossible). People who assert that the solubility of salt is contingent tend not to know much about chemistry.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / c. Essence and laws
Most laws supervene on fundamental laws, which are explained by basic powers [Bird, by Friend/Kimpton-Nye]
     Full Idea: According to Bird, non-fundamental laws supervene on fundamental laws, and so are ultimately explained by fundamental powers.
     From: report of Alexander Bird (Nature's Metaphysics [2007]) by Friend/Kimpton-Nye - Dispositions and Powers 3.6.1
     A reaction: This looks like the picture I subscribe to. Roughly, fundamental laws are explained by powers, and non-fundamental laws are explained by properties, which are complexes of powers. 'Fundamental' may not be a precise term!
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / d. Knowing essences
If flame colour is characteristic of a metal, that is an empirical claim needing justification [Bird]
     Full Idea: I might say that flame colours are a characteristic feature of metals, but this is an empirical proposition which is in part about the unobserved, and stands in need of justification.
     From: Alexander Bird (Philosophy of Science [1998], Ch.5)
     A reaction: This draws attention to the fact that essentialism is not just a metaphysical theory, but is also part of the scientific enterprise. Among things to research about metals is the reason why they have a characteristic flame.
26. Natural Theory / D. Laws of Nature / 9. Counterfactual Claims
Essentialism can't use conditionals to explain regularities, because of possible interventions [Bird]
     Full Idea: The straightforward dispositional essentialist account of laws by subjunctive conditionals is false because dispositions typically suffer from finks and antidotes.
     From: Alexander Bird (Nature's Metaphysics [2007], 3.4)
     A reaction: [Finks and antidotes intervene before a disposition can take effect] This seems very persuasive to me, and shows why you can't just explain laws as counterfactual or conditional claims. Explanation demands what underlies them.
27. Natural Reality / B. Modern Physics / 4. Standard Model / d. Mass
In Newton mass is conserved, but in Einstein it can convert into energy [Bird]
     Full Idea: According to Newton mass is conserved, while in Einstein's theory mass is not conserved but can be converted into and from energy.
     From: Alexander Bird (Philosophy of Science [1998])
     A reaction: Perhaps this is the most fundamental difference between the theories. It certainly suggests that 'mass' was a conventional concept rather than a natural one. Maybe the relative notion of 'weight' is more natural than 'mass'.
27. Natural Reality / D. Time / 1. Nature of Time / b. Relative time
The relational view of space-time doesn't cover times and places where things could be [Bird]
     Full Idea: The obvious problem with the simple relational view of space and time is that it fails to account for the full range of spatio-temporal possibility. There seem to be times and places where objects and events could be, but are not.
     From: Alexander Bird (Nature's Metaphysics [2007], 7.3.2)
     A reaction: This view seems strongly supported by intuition. I certainly don't accept the views of physicists and cosmologists on the subject, because they seem to approach the whole thing too instrumentally.