Combining Philosophers

All the ideas for Archimedes, Volker Halbach and Stephen Mumford

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128 ideas

1. Philosophy / D. Nature of Philosophy / 6. Hopes for Philosophy
Science studies phenomena, but only metaphysics tells us what exists [Mumford]
     Full Idea: Science deals with the phenomena, ..but it is metaphysics, and only metaphysics, that tells us what ultimately exists.
     From: Stephen Mumford (Laws in Nature [2004], 01.2)
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.
2. Reason / A. Nature of Reason / 1. On Reason
Many forms of reasoning, such as extrapolation and analogy, are useful but deductively invalid [Mumford]
     Full Idea: There are many forms of reasoning - extrapolation, interpolation, and other arguments from analogy - that are useful but deductively invalid.
     From: Stephen Mumford (Laws in Nature [2004], 04.4)
     A reaction: [He cites Molnar for this]
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)
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]
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.
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
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)
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)
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).
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
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?
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)
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 / 3. Axioms for Geometry
Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz]
     Full Idea: Archimedes gave a sort of definition of 'straight line' when he said it is the shortest line between two points.
     From: report of Archimedes (fragments/reports [c.240 BCE]) by Gottfried Leibniz - New Essays on Human Understanding 4.13
     A reaction: Commentators observe that this reduces the purity of the original Euclidean axioms, because it involves distance and measurement, which are absent from the purest geometry.
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 / 1. Nature of Existence
For Humeans the world is a world primarily of events [Mumford]
     Full Idea: For Humeans the world is a world primarily of events.
     From: Stephen Mumford (Laws in Nature [2004], 03.6)
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 / D. Theories of Reality / 2. Realism
Modest realism says there is a reality; the presumptuous view says we can accurately describe it [Mumford]
     Full Idea: The claim of modest realism is that there is a subject-independent reality; the presumptuous claim is that we are capable of describing that reality accurately.
     From: Stephen Mumford (Dispositions [1998], 09.1)
     A reaction: And the super-presumptuous claim is that there only exists one ultimate accurate description of reality. I am happy to call myself a Modest Realist on this one.
7. Existence / D. Theories of Reality / 4. Anti-realism
Anti-realists deny truth-values to all statements, and say evidence and ontology are inseparable [Mumford]
     Full Idea: The anti-realist declines to permit that all statements have truth-values. ...The essence of the anti-realist position is that evidence and ontology cannot be separated.
     From: Stephen Mumford (Dispositions [1998], 03.6)
     A reaction: [second half on p.51] The idea that evidence and ontology are 'inseparable' strikes me as an absurd idea. The proposal that you should not speculate about ontology without some sort of evidence is, of course, not unreasonable.
8. Modes of Existence / B. Properties / 3. Types of Properties
Dispositions and categorical properties are two modes of presentation of the same thing [Mumford]
     Full Idea: The dispositional and the categorical are correctly understood just as two modes of presentation of the same instantiated properties.
     From: Stephen Mumford (Dispositions [1998], 08.6)
     A reaction: This is Mumford's own conclusion, after discussing the views of Armstrong. How about 'a disposition is the modal profile' of a categorical property?
8. Modes of Existence / B. Properties / 6. Categorical Properties
Categorical predicates are those unconnected to functions [Mumford]
     Full Idea: A predicate which is conceptually connected to no function ... is a categorical predicate.
     From: Stephen Mumford (Dispositions [1998], 09.7)
     A reaction: This is an expansion of Mumford's own theory of dispositions, as functional. Does a cork in a wine bottle have a function, but without doing anything? It seems to achieve its function purely through its structure.
Categorical properties and dispositions appear to explain one another [Mumford]
     Full Idea: Though categorical properties provide explanations for dispositions, categorical properties are also explained by dispositions; hence neither category uniquely explains the other.
     From: Stephen Mumford (Dispositions [1998], 05.3)
     A reaction: The conclusion doesn't seem to follow. It depends which one is found at the bottom level. It can go up from a basic disposition, to a categorical property, to another disposition - or the other way around.
There are four reasons for seeing categorical properties as the most fundamental [Mumford]
     Full Idea: Four reasons for reducing everything to the categorical are: categorical predicates have wider scope; dispositions are variably realised by the categorical; categorical is 1st order, dispositions 2nd; categorical properties are explanatorily basic.
     From: Stephen Mumford (Dispositions [1998], 08.5)
     A reaction: I particularly reject the fourth reason, as I take categorical properties as still in need of explanation. The categorical view is contingent (and Humean), but I take the categorical properties to be necessitated by the underlying powers.
8. Modes of Existence / B. Properties / 7. Emergent Properties
A lead molecule is not leaden, and macroscopic properties need not be microscopically present [Mumford]
     Full Idea: Though lead is said to be composed of molecules of lead, these molecules are not leaden in the everyday sense of the word. This suggests that a property need not be present at the microscopic level in order to be present at the macroscopic level.
     From: Stephen Mumford (Dispositions [1998], 02.3)
     A reaction: [He quotes Joske] This strikes me as a key principle to grasp about properties. One H2O molecule is not water, any more than a brick is a house! Nearly all properties (or all?) are 'emergent' (in the sensible, non-mystical use of that word).
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
Dispositions are attacked as mere regularities of events, or place-holders for unknown properties [Mumford]
     Full Idea: Dispositions are attacked as either just saying how something will behave (logical fictions about regularities of events), or as primitive pre-scientific terms like 'phlogiston', place-holders used when we are ignorant of real properties.
     From: Stephen Mumford (Dispositions [1998], 01.1)
     A reaction: [compressed] The first view he calls the Ryle-Wittgenstein view, which seems to track back to Hume.
Properties are just natural clusters of powers [Mumford]
     Full Idea: The view of properties I find most attractive is one in which they are natural clusters of, and exhausted by, powers (plus other connections to other properties).
     From: Stephen Mumford (Laws in Nature [2004], 10.6)
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
If dispositions have several categorical realisations, that makes the two separate [Mumford]
     Full Idea: We might claim that dispositions are variably realized by a number of categorical bases; therefore they must be distinct from those bases.
     From: Stephen Mumford (Dispositions [1998], 05.4)
     A reaction: Cars can be realised by a variety of models, therefore models are not cars? This might work if dispositions are only characterised functionally, as Mumford proposes, but I'm not convinced.
Dispositions are classifications of properties by functional role [Mumford]
     Full Idea: A dispositional property is the classification of a property according to its functional role....[p.85] What is essential to a disposition - its identity condition - is its functional role.
     From: Stephen Mumford (Dispositions [1998], 04.5)
     A reaction: This is Mumford's view of dispositions. I am wary of any proposal to define something according to its role, because it must have an intrinsic nature which equips it to have that role.
I say the categorical base causes the disposition manifestation [Mumford]
     Full Idea: The view I promote is one where the categorical base is a cause of the disposition manifestation.
     From: Stephen Mumford (Dispositions [1998], 05.5)
     A reaction: It seems to me (I think) that the most basic thing has to be a power, whose nature is intrinsically beyond our grasp, and that categorical properties are the result of these powers. Powers are dispositional in character.
8. Modes of Existence / C. Powers and Dispositions / 5. Powers and Properties
All properties must be causal powers (since they wouldn't exist otherwise) [Mumford]
     Full Idea: It seems that every property must be a causal power, since every property must be causally potent (as a necessary condition of its very existence).
     From: Stephen Mumford (Dispositions [1998], 04.7)
     A reaction: Mumford cautiously endorses this idea, which seems to rest on the thesis that 'to exist is to have causal powers'. I think I am even keener on it than Mumford is. Powers and properties need to be disentangled, however.
Intrinsic properties are just causal powers, and identifying a property as causal is then analytic [Mumford]
     Full Idea: Understanding intrinsic properties as being causal powers is likely to be most profitable, and, if true, renders the causal criterion of property existence true analytically.
     From: Stephen Mumford (Dispositions [1998], 06.2)
     A reaction: [He cites E.Fales on this] I'm inclined to think that in the ultimate ontology the notion of a 'property' drops out. There are true causal powers, and then conventional human ways of grouping such powers together and naming them.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
Dispositions can be contrasted either with occurrences, or with categorical properties [Mumford]
     Full Idea: For some the notion of a disposition is contrasted with the notion of an occurrence; for others, it is contrasted with that of a categorical property.
     From: Stephen Mumford (Dispositions [1998], 01.6)
     A reaction: I vote for dispositions over the other two, but I take the categorical properties to be the main rival.
Dispositions are ascribed to at least objects, substances and persons [Mumford]
     Full Idea: Dispositions are ascribed to at least three distinguishable classes of things: objects, substances, and persons.
     From: Stephen Mumford (Dispositions [1998], 01.1)
     A reaction: Are dispositions not also ascribed to properties? Magnetism has a disposition to attract iron filings?
Unlike categorical bases, dispositions necessarily occupy a particular causal role [Mumford]
     Full Idea: The idea of a disposition occupying a different causal role involves a conceptual confusion, ...but there is no conceptual or logical absurdity in a categorical base occupying a different causal role.
     From: Stephen Mumford (Dispositions [1998], 07.3)
     A reaction: This is the core of Mumford's theory of dispositions. I'm beginning to think that dispositions are merely ways we have of describing and labelling functional mechanisms, and so 'dispositions' drop out of the final story.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / b. Dispositions and powers
If dispositions are powers, background conditions makes it hard to say what they do [Mumford]
     Full Idea: The realist says that disposition ascriptions are ascriptions of real powers. This leaves unanswered the question, 'power to do what?' The problem of background conditions means that the realist cannot say what it is that a power is a power to do.
     From: Stephen Mumford (Dispositions [1998], 04.9)
     A reaction: It is hard to say what a disposition will do, under any other account of dispositions. I would take a power to be defined by a 'modal profile', rather than an actual account of what it will lead to.
Maybe dispositions can replace powers in metaphysics, as what induces property change [Mumford]
     Full Idea: Dispositions can regain the metaphysical role traditionally ascribed to real powers: the that-in-virtue-of-which-something-will-G, if F.
     From: Stephen Mumford (Dispositions [1998], 06.9)
     A reaction: The attraction is that dispositions can be specified a little more clearly (especially in Mumford's functional version) whereas there may be no more to say about a power once it has been located and named.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / c. Dispositions as conditional
Orthodoxy says dispositions entail conditionals (rather than being equivalent to them) [Mumford]
     Full Idea: The orthodox realist view has it that what makes an ascription a disposition ascription is not that it is equivalent to a conditional proposition but that it entails one.
     From: Stephen Mumford (Dispositions [1998], 04.7)
     A reaction: Mumford says that Martin has shown that dispositions need not entail conditionals (when a 'fink' is operating, something which intervenes between disposition and outcome).
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / e. Dispositions as potential
Dispositions are not just possibilities - they are features of actual things [Mumford]
     Full Idea: Dispositions should correctly be understood as more than mere possibilities. To say something has a disposition is to say something about how it is actually.
     From: Stephen Mumford (Dispositions [1998], Pref)
     A reaction: To me this is a basic axiom of metaphysics. The word 'power' serves well for the actual embodiment of a disposition. A power gives rise to one or more dispositions. Or one or more powers give rise to a disposition?
There could be dispositions that are never manifested [Mumford]
     Full Idea: It seems plausible that a disposition could be possessed though no manifestation events occur.
     From: Stephen Mumford (Dispositions [1998], 01.6)
     A reaction: It is more than 'plausible' - it is screamingly obvious to everybody, apart from a few philosophers. "Some mute inglorious Milton here may rest" (Gray's Elegy).
8. Modes of Existence / C. Powers and Dispositions / 7. Against Powers
If every event has a cause, it is easy to invent a power to explain each case [Mumford]
     Full Idea: Given any event, and the assumption that every event has a cause, then some power can always be invented as the cause of that event.
     From: Stephen Mumford (Dispositions [1998], 06.6)
     A reaction: This is a useful warning, and probably explains why 'powers' fell out of fashion in scientifice theorising. They seem to make a return, though, as an appropriate term for the bottom level of each of our explanations.
Traditional powers initiate change, but are mysterious between those changes [Mumford]
     Full Idea: In the old-fashioned sense, 'powers' are real potentialities that initiate changes but seem to have a mysterious existence in between those changes.
     From: Stephen Mumford (Dispositions [1998], 07.10)
     A reaction: What is a person when they are asleep? What is a dishwasher when it isn't running? What is gunpowder when it doesn't explode? We all understand latent powers. To see them as a 'mystery' is to want to know too much.
Categorical eliminativists say there are no dispositions, just categorical states or mechanisms [Mumford]
     Full Idea: The categorical eliminativist claims that there are no dispositional properties. All properties must be conceived of as categorical states or mechanisms, in the spirit of Boyle's explanation of powers.
     From: Stephen Mumford (Dispositions [1998], 08.3A)
     A reaction: What is the difference between a structure and a mechanism? How do we distinguish an active from an inactive mechanism? Without powers or dispositions, nature is dead junk.
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
A 'porridge' nominalist thinks we just divide reality in any way that suits us [Mumford]
     Full Idea: A 'porridge' nominalist denies natural kinds, and thinks there are no objective divisions in reality, so concepts or words can be used by a community to divide the world up in any way that suits their purposes.
     From: Stephen Mumford (Laws in Nature [2004], 07.3)
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
If properties are clusters of powers, this can explain why properties resemble in degrees [Mumford]
     Full Idea: If a cluster of ten powers exhausts property F, and property G differs in respect of just one power, this might explain why properties can resemble other properties and in different degrees.
     From: Stephen Mumford (Laws in Nature [2004], 10.6)
     A reaction: I love this. The most intractable problem about properties and universals is that of abstract reference - pink resembles red more than pink resembles green. If colours are clusters of powers, red and pink share nine out of ten of them.
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
Substances, unlike aggregates, can survive a change of parts [Mumford]
     Full Idea: Substances can survive a change in their parts in a way that a mere aggregate of parts.
     From: Stephen Mumford (Metaphysics: a very short introduction [2012], 3)
     A reaction: A simple but very important idea. If we then distinguish between 'substances' and 'aggregates' we get a much clearer grip on things. Is the Ship of Theseus a substance or an aggregate? There is no factual answer to that. What do you want to explain?
9. Objects / D. Essence of Objects / 11. Essence of Artefacts
Many artefacts have dispositional essences, which make them what they are [Mumford]
     Full Idea: Thermostats, thermometers, axes, spoons, and batteries have dispositional essences, which make them what they are.
     From: Stephen Mumford (Dispositions [1998], 01.2 iv)
     A reaction: I would have thought that we could extend this proposal well beyond artefacts, but it certainly seems particularly clear in artefacts, where a human intention seems to be inescapably involved.
9. Objects / D. Essence of Objects / 14. Knowledge of Essences
How can we show that a universally possessed property is an essential property? [Mumford]
     Full Idea: Essentialists fail to show how we ascend from being a property universally possessed, by all kind members, to the status of being an essential property.
     From: Stephen Mumford (Laws in Nature [2004], 07.5)
     A reaction: This is precisely where my proposal comes in - the essential properties, as opposed to the accidentaly universals, are those which explain the nature and behaviour of each kind of thing (and each individual thing).
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 / B. Possibility / 3. Combinatorial possibility
Maybe possibilities are recombinations of the existing elements of reality [Mumford]
     Full Idea: It has been suggested that we could think of possibilities as recombinations of all the existing elements of reality.
     From: Stephen Mumford (Metaphysics: a very short introduction [2012], 8)
     A reaction: [Armstrong 1989 is the source] The obvious problem would be that the existence of an entirely different reality would be impossible, if this was all possibility could be. It seems to cramp the style of the possible too much. Are properties elements?
Combinatorial possibility has to allow all elements to be combinable, which seems unlikely [Mumford]
     Full Idea: The combinatorial account only works if you allow that the elements are recombinable. ...But could Lincoln really have been green? It seems possible that you could jump to the moon, unless we impose some restrictions.
     From: Stephen Mumford (Metaphysics: a very short introduction [2012], 8)
     A reaction: Mumford suggests different combination rules for logical and natural possibility. The general objection is that combinatorial possibility is too permissive - which it clearly is.
Combinatorial possibility relies on what actually exists (even over time), but there could be more [Mumford]
     Full Idea: Can combinatorial possibility deliver enough possibilities? It uses the existing elements, but there might have been one more particular or one more property. Even extended over time, the elements seem finite, yet there could have been more.
     From: Stephen Mumford (Metaphysics: a very short introduction [2012], 8)
     A reaction: [compressed] One objection is that the theory allows too much, and now the objection is that it allows too little. Both objections are correct, so that's the end of that. But I admire the attempt to base modality on actuality.
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
Truth-functional conditionals can't distinguish whether they are causal or accidental [Mumford]
     Full Idea: If a conditional remains truth-functional it is incapable of expressing the fact that the connection between antecedent and consequent in the conditional is a causal one rather than merely accidental
     From: Stephen Mumford (Dispositions [1998], 03.8)
     A reaction: This is the first step towards an account of conditionals which will work in real life rather than merely in classical logic.
10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
Dispositions are not equivalent to stronger-than-material conditionals [Mumford]
     Full Idea: The conclusion that disposition ascriptions are not equivalent to stronger-than-material conditionals is largely to be accepted.
     From: Stephen Mumford (Dispositions [1998], 04.7)
     A reaction: [he attributes the view to C.B.Martin 1994] It is hard to see how to describe a disposition in anything other than conditional terms. Mumford's 'functional role' probably has to be described conditionally. It is how the conditional cashes out.
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
Nomothetic explanations cite laws, and structural explanations cite mechanisms [Mumford]
     Full Idea: A nomothetic explanation appeals to laws where the explanandum is shown to be an instance of a general law. ...The alternative is a structural explanation, which postulates a mechanism, opening up a hidden world.
     From: Stephen Mumford (Dispositions [1998], 06.4)
     A reaction: [He cites E.McMullin 1978] I am very much in favour of structural explanations, and opposed to nomothetic ones. That is, nomothetic accounts are only the first step towards an explanation - perhaps a mere identification of the explanandum.
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
General laws depend upon the capacities of particulars, not the other way around [Mumford]
     Full Idea: Laws, qua true generalities, if they exist at all, are ontologically parasitic upon the capacities of particulars, rather than the other way round.
     From: Stephen Mumford (Dispositions [1998], 10.6)
     A reaction: Quite so. And hence trying to explain a particular behaviour by saying that it falls under a law is absurdly circular and vacuous.
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
If fragile just means 'breaks when dropped', it won't explain a breakage [Mumford]
     Full Idea: If fragile means nothing more than 'breaks when dropped', then it is no explanation of why something breaks when dropped.
     From: Stephen Mumford (Dispositions [1998], 06.5)
     A reaction: His point is that you have to unpack the notion of fragile, which presumably cites underlying mechanisms. This is the 'virtus dormitiva' problem - but that explanation of opium's dormitive powers is not entirely stupid.
14. Science / D. Explanation / 3. Best Explanation / b. Ultimate explanation
Maybe dispositions can replace the 'laws of nature' as the basis of explanation [Mumford]
     Full Idea: I will consider the case for an ontology of real dispositions replacing the so-called laws of nature as the basic building blocks of explanation.
     From: Stephen Mumford (Dispositions [1998], 10.1)
     A reaction: This precisely summarises the view I am exploring, with a particular focus on real essences. I certainly think the 'laws of nature' must go. See Mumford's second book on this.
To avoid a regress in explanations, ungrounded dispositions will always have to be posited [Mumford]
     Full Idea: The nature of explanation is such that ungrounded dispositions will always have to be posited in order to avoid a regress of explanation.
     From: Stephen Mumford (Dispositions [1998], 10.6)
     A reaction: This seems to be right, but leaves it open to mock the proposals as 'virtus dormitiva' - empty place-holders that ground explanations but do no explanatory work. What else can be done, though?
Subatomic particles may terminate explanation, if they lack structure [Mumford]
     Full Idea: The behaviour of subatomic particles cannot be further analysed into structures and this may tempt us to regard these as instances of 'brute' ungrounded dispositions which end any possible regress of explanation.
     From: Stephen Mumford (Dispositions [1998], 06.4)
     A reaction: This seems right, if it is 'structural' explanations we are after (as I think we are) which look for mechanisms. An electron seems to be just three dispositions and no structure, so there is nothing more to say. Ladyman scorns this account.
14. Science / D. Explanation / 4. Explanation Doubts / a. Explanation as pragmatic
Ontology is unrelated to explanation, which concerns modes of presentation and states of knowledge [Mumford]
     Full Idea: Nothing about ontology is at stake in questions of explanation, for explanatory success is contingent upon the modes of presentation of explanans and explananda, and relative states of knowledge and ignorance.
     From: Stephen Mumford (Dispositions [1998], 06.8)
     A reaction: There are real facts about the immediate and unusual causes which immediately precede an event, and these might be candidates for a real explanation. There are also real mechanisms and powers which dictate a things behaviour.
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 / 4. Source of Kinds
Natural kinds, such as electrons, all behave the same way because we divide them by dispositions [Mumford]
     Full Idea: Regularities exist because we classify kinds on the basis of their dispositions, not on pre-established divisions of kinds. The dispositions are the basis for the division into kinds, which is why all electrons behave in the same way.
     From: Stephen Mumford (Dispositions [1998], 10.7)
     A reaction: This strikes me as being so obvious that it is hardly worth saying, and yet an enormous number of philosophers seem to have been led up the garden path by the notion of a 'kind', probably under the influence of Kripke, Putnam and Wiggins.
26. Natural Theory / C. Causation / 1. Causation
Causation interests us because we want to explain change [Mumford]
     Full Idea: Like Aristotle, the reason we are really interested in causation is because we want to be able to explain change.
     From: Stephen Mumford (Contemporary Efficient Causation: Aristotelian themes [2014], 8)
     A reaction: This pinpoints a very important and simple idea. It raises the question (among others) of whether we have just invented this thing called 'causation', because no explanation of change was visible. Hume certainly couldn't see any explanation.
26. Natural Theory / C. Causation / 9. General Causation / b. Nomological causation
Singular causes, and identities, might be necessary without falling under a law [Mumford]
     Full Idea: One might have a singularist view of causation in which a cause necessitates its effect, but they need not be subsumed under a law, ..and there are identities which are metaphysically necessary without being laws of nature.
     From: Stephen Mumford (Laws in Nature [2004], 04.5)
26. Natural Theory / C. Causation / 9. General Causation / c. Counterfactual causation
We can give up the counterfactual account if we take causal language at face value [Mumford]
     Full Idea: If we take causal language at face value and give up reducing causal concepts to non-causal, non-modal concepts, we can give up the counterfactual dependence account.
     From: Stephen Mumford (Laws in Nature [2004], 10.5)
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
It is only properties which are the source of necessity in the world [Mumford]
     Full Idea: If laws do not give the world necessity, what does? I argue the positive case for it being properties, and properties alone, that do the job (so we might call them 'modal properties').
     From: Stephen Mumford (Laws in Nature [2004], 10.1)
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
In the 'laws' view events are basic, and properties are categorical, only existing when manifested [Mumford]
     Full Idea: In the 'laws' world view, events are the basic ontological unit and properties are parasitic upon them. Properties exist only in virtue of their instantiation in events. Properties are categorical, because they are only manifested in the present.
     From: Stephen Mumford (Dispositions [1998], 10.2)
     A reaction: Mumford rejects this view, and I am with him all the way. The first requirement is that properties be active, and not inert. See Leibniz on this.
There are four candidates for the logical form of law statements [Mumford]
     Full Idea: The contenders for the logical form of a law statement are 1) a universally quantified conditional, 2) a second-order relation between first-order universals, 3) a functional equivalence, and 4) a dispositional characteristic of a natural kind.
     From: Stephen Mumford (Laws in Nature [2004], 10.3)
26. Natural Theory / D. Laws of Nature / 3. Laws and Generalities
Without laws, how can a dispositionalist explain general behaviour within kinds? [Mumford]
     Full Idea: The problem is how, without general laws, can the dispositionalist explain why generalities in behaviour are true of kinds.
     From: Stephen Mumford (Dispositions [1998], 10.3)
     A reaction: And the answer is to make kinds depend on individuals, and not vice versa, and then point to the necessary patterns that arise from conjunctions of individual dispositions, given their identity in many individuals.
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
Dretske and Armstrong base laws on regularities between individual properties, not between events [Mumford]
     Full Idea: The improved Dretske/Armstrong regularity view of laws dispenses with the empiricist articulation of them in terms of events, and construes them as singular statements of fact that describe relations between properties.
     From: Stephen Mumford (Dispositions [1998], 10.4)
     A reaction: They then seem to go a bit mystical, by insisting that the properties are 'universals' (even if they have to be instantiated). Universals explain nothing.
Regularities are more likely with few instances, and guaranteed with no instances! [Mumford]
     Full Idea: It seems that the fewer the instances, the more likely it is that there be a regularity, ..and if there are no cases at all, and no S is P, that is a regularity.
     From: Stephen Mumford (Laws in Nature [2004], 03.3)
     A reaction: [He attributes the second point to Molnar]
Pure regularities are rare, usually only found in idealized conditions [Mumford]
     Full Idea: Pure regularities are not nearly as common as might have been thought, and are usually only to be found in simplified or idealized conditions.
     From: Stephen Mumford (Laws in Nature [2004], 05.3)
     A reaction: [He cites Nancy Cartwright 1999 for this view]
Regularity laws don't explain, because they have no governing role [Mumford]
     Full Idea: A regularity-law does not explain its instances, because such laws play no role in determining or governing their instances.
     From: Stephen Mumford (Laws in Nature [2004], 09.7)
     A reaction: Good. It has always seemed to me entirely vacuous to explain an event simply by saying that it falls under some law.
It is a regularity that whenever a person sneezes, someone (somewhere) promptly coughs [Mumford]
     Full Idea: It is no doubt a true regularity that every time I sneeze, someone, somewhere in the world, immediately coughs.
     From: Stephen Mumford (Dispositions [1998], 10.4)
     A reaction: Not a huge problem for the regularity theory of laws, but the first challenge that it must meet.
Would it count as a regularity if the only five As were also B? [Mumford]
     Full Idea: While it might be true that for all x, if Ax then Bx, would we really want to count it as a genuine regularity in nature if only five things were A (and all five were also B)?
     From: Stephen Mumford (Laws in Nature [2004], 03.3)
26. Natural Theory / D. Laws of Nature / 4. Regularities / b. Best system theory
If the best system describes a nomological system, the laws are in nature, not in the description [Mumford]
     Full Idea: If the world really does have its own nomological structure, that a systematization merely describes, why are the laws not to be equated with the nomological structure itself, rather than with the system that describes it?
     From: Stephen Mumford (Laws in Nature [2004], 03.4)
The best systems theory says regularities derive from laws, rather than constituting them [Mumford]
     Full Idea: The best systems theory (of Mill-Ramsey-Lewis) says that laws are not seen as regularities but, rather, as those things from which regularities - or rather, the whole world history including the regularities and everything else - can be derived.
     From: Stephen Mumford (Laws in Nature [2004], 03.4)
     A reaction: Put this way, the theory invites questions about ontology. Regularities are just patterns in physical reality, but axioms are propositions. So are they just features of human thought, or do these axioms actuallyr reside in reality. Too weak or too strong.
26. Natural Theory / D. Laws of Nature / 5. Laws from Universals
Laws of nature are necessary relations between universal properties, rather than about particulars [Mumford]
     Full Idea: The core of the Dretske-Tooley-Armstrong view of the late 70s is that we have a law of nature when we have a relation of natural necessitation between universals. ..The innovation was that laws are about properties, and only indirectly about particulars.
     From: Stephen Mumford (Laws in Nature [2004], 06.2)
     A reaction: It sounds as if we should then be able to know the laws of nature a priori, since that was Russell's 1912 definition of a priori knowledge.
If laws can be uninstantiated, this favours the view of them as connecting universals [Mumford]
     Full Idea: If there are laws that are instantiated in no particulars, then this would seem to favour the theory that laws connect universals rather than particulars.
     From: Stephen Mumford (Laws in Nature [2004], 06.4)
     A reaction: There is a dispute here between the Platonic view of uninstantiated universals (Tooley) and the Aristotelian instantiated view (Armstrong). Mumford and I prefer the dispositional account.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / b. Scientific necessity
The necessity of an electron being an electron is conceptual, and won't ground necessary laws [Mumford]
     Full Idea: The logical necessity of physical laws is not required by dispositional essentialism. An electron would not be an electron if its behaviour were different from the behaviour it has in the actual world, but this necessity is purely conceptual.
     From: Stephen Mumford (Dispositions [1998], 10.8)
     A reaction: [He is particularly aiming this at Ellis and Lierse 1994] This may be missing the point. Given those electron dispositions, the electrons necessitate law-like happenings. Whether a variable entity is called an 'electron' is trivial.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / c. Essence and laws
Laws of nature are just the possession of essential properties by natural kinds [Mumford]
     Full Idea: If dispositional essentialism is granted, then there is a law of nature wherever there is an essential property of a natural kind; laws are just the havings of essential properties by natural kinds.
     From: Stephen Mumford (Laws in Nature [2004], 07.2)
     A reaction: [He is expounding Ellis's view]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / d. Knowing essences
Some dispositions are so far unknown, until we learn how to manifest them [Mumford]
     Full Idea: It seems reasonable to assume that there are some dispositions of some things of which we are not aware because we have not yet discovered the way to get these dispositions to manifest.
     From: Stephen Mumford (Dispositions [1998], 03.7)
     A reaction: This strikes me as a pretty good description of what scientists are currently doing when, for example, they build a new particle accelerator.
To distinguish accidental from essential properties, we must include possible members of kinds [Mumford]
     Full Idea: Where properties are possessed by all kind members, we must distinguish the accidental from essential ones by considering all actual and possible kind members.
     From: Stephen Mumford (Laws in Nature [2004], 07.5)
     A reaction: This is why we must treat possibilities as features of the actual world.
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
The Central Dilemma is how to explain an internal or external view of laws which govern [Mumford]
     Full Idea: The Central Dilemma about laws of nature is that, if they have some governing role, then they must be internal or external to the things governed, and it is hard to give a plausible account of either view.
     From: Stephen Mumford (Laws in Nature [2004], 09.2)
     A reaction: This dilemma is the basis of Mumford's total rejection of 'laws of nature'. I think I agree.
You only need laws if you (erroneously) think the world is otherwise inert [Mumford]
     Full Idea: Laws are a solution to a problem that was misconceived. Only if you think that the world would be otherwise inactive or inanimate, do you have the need to add laws to your ontology.
     From: Stephen Mumford (Laws in Nature [2004], 01.5)
     A reaction: This is a bold and extreme view - and I agree with it. I consider laws to be quite a useful concept when discussing nature, but they are not part of the ontology, and they don't do any work. They are metaphysically hopeless.
There are no laws of nature in Aristotle; they became standard with Descartes and Newton [Mumford]
     Full Idea: Laws do not appear in Aristotle's metaphysics, and it wasn't until Descartes and Newton that laws entered the intellectual mainstream.
     From: Stephen Mumford (Laws in Nature [2004], 01.5)
     A reaction: Cf. Idea 5470.