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All the ideas for 'Axiomatic Theories of Truth', 'Outline of a System of Utilitarianism' and 'LOT 2'

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90 ideas

1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Who cares what 'philosophy' is? Most pre-1950 thought doesn't now count as philosophy [Fodor]
     Full Idea: Who cares what gets called 'philosophy'? It's my impression that most of what happened in philosophy before 1950 wouldn't qualify according to the present usage.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.5)
     A reaction: A rather breath-taking remark. Fodor is, of course, a devotee of David Hume, and of Descartes, but he never seems to refer to Greeks at all. Personally I presume that if you aren't doing what Plato and Aristotle were interested in, it ain't philosophy.
1. Philosophy / F. Analytic Philosophy / 3. Analysis of Preconditions
Definitions often give necessary but not sufficient conditions for an extension [Fodor]
     Full Idea: Attempts to define a term frequently elicit necessary but not sufficient conditions for membership of its extension. This is called the 'X problem', as in 'kill' means 'cause to die' plus X.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.2.1 n3)
     A reaction: Fodor is one of the great sceptics about definition. I just don't see why we have to have totally successful definitions before we can accept the process as a worthwhile endeavour.
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 / 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.
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
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
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)
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.
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 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)
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)
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 / 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
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 / E. Structures of Logic / 2. Logical Connectives / d. and
A truth-table, not inferential role, defines 'and' [Fodor]
     Full Idea: I'm inclined to think that 'and' is defined by its truth-table (and not, for example, by its 'inferential-role').
     From: Jerry A. Fodor (LOT 2 [2008], Ch.7)
     A reaction: Sounds right, on my general principle that something can only have a function if it has an intrinsic nature. The truth-table just formalises normal understanding of 'and', according to what it makes true.
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 / F. Referring in Logic / 1. Naming / a. Names
Names in thought afford a primitive way to bring John before the mind [Fodor]
     Full Idea: Names in thought (in contrast to, say, descriptions in thought) afford a primitive way of bringing John before the mind.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3 App)
     A reaction: I think the 'file' account of concepts which Fodor has now latched onto gives a wonderful account of names. They are simple if you haven't opened the file yet (like 'Louis', in Evans's example).
'Paderewski' has two names in mentalese, for his pianist file and his politician file [Fodor]
     Full Idea: Paderewski (as pianist and as politician) has two names in Mentalese. If you think there are two Paderewskis, it's important that what you get when you retrieve the pianist file differs from the politician file. You can then merge the two files.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3 App)
     A reaction: The same will apply to 'Hespherus' and 'Phosphorus'. We can re-separate the 'morning star' and 'evening star' files if we wish to discuss ancient Egyptian attitudes to such things. I love this idea of Fodor's. Explanations flow from it.
5. Theory of Logic / K. Features of Logics / 2. Consistency
P-and-Q gets its truth from the truth of P and truth of Q, but consistency isn't like that [Fodor]
     Full Idea: The truth of P-and-Q is (roughly) a function of the truth of P and the truth of Q; but the consistency of P&Q isn't a function of the consistency of P and the consistency of Q.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.4.5 n33)
     A reaction: This is a nice deep issue. Fodor is interested in artificial intelligence at this point, but I am interested in the notion of coherence, as found in good justifications. Even consistency isn't elementary logic, never mind coherence.
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 / 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.
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 / 1. Possibility
There's statistical, logical, nomological, conceptual and metaphysical possibility [Fodor]
     Full Idea: Statistically, logically, nomologically, conceptually, and metaphysically possible. That's all the kinds of possibility there are this week, but feel free to add others.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.4.3)
     A reaction: There's also epistemic possibility (possibility 'for all I know'), but I suppose that isn't the real thing. How about 'imaginative possibility' (possibility 'as far as I can imagine')?
11. Knowledge Aims / A. Knowledge / 4. Belief / d. Cause of beliefs
Some beliefs are only inferred when needed, like 'Shakespeare had not telephone' [Fodor]
     Full Idea: Maybe some of your beliefs are inferred 'online' from what you have in your files, along with your inferential rules. 'Shakespeare didn't have a telephone' is a classic example, which we infer if the occasion arises.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3 App)
     A reaction: A highly persuasive example. There seem to be a huge swathe of blatantly obvious beliefs (especially negative ones) which may never cross our minds during an entire lifetime, but to which we certainly subscribe.
11. Knowledge Aims / A. Knowledge / 6. Knowing How
Knowing that must come before knowing how [Fodor]
     Full Idea: Thought about the world is prior to thought about how to change the world. Accordingly, knowing that is prior to knowing how. Descartes was right, and Ryle was wrong.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.1)
     A reaction: The classical example is knowing how to ride a bicycle, when few people can explain what is involved. Clearly you need quite a bit of propositional knowledge before you step on a bike. How does Fodor's claim work for animals?
12. Knowledge Sources / D. Empiricism / 3. Pragmatism
Pragmatism is the worst idea ever [Fodor]
     Full Idea: Pragmatism is perhaps the worst idea that philosophy ever had.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.1)
     A reaction: Not an argument, but an interesting sign of the times. Most major modern American philosophers, such as Quine, seem to fit some loose label of 'pragmatist'. I always smell a feeble relativism, and a refusal to face the interesting questions.
15. Nature of Minds / A. Nature of Mind / 1. Mind / c. Features of mind
Mental states have causal powers [Fodor]
     Full Idea: Mental states have causal powers.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.2.3)
     A reaction: I quote this because it gives you the link between a general account of causal powers as basic to reality, and an active account of what the mind is. It has to be a key link in a decent modern unified account of the world. See Idea 12638.
15. Nature of Minds / C. Capacities of Minds / 7. Seeing Resemblance
The different types of resemblance don't resemble one another [Fodor]
     Full Idea: The ways in which different kinds of thing are similar to one another aren't, in general, similar to one another.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.5.4)
     A reaction: Nice, but I think one would say that they lack similarity at the level of primary thought, but have obvious similarity (as concept-connectors) at the level of meta-thought.
17. Mind and Body / C. Functionalism / 2. Machine Functionalism
In the Representational view, concepts play the key linking role [Fodor]
     Full Idea: If the Representational Theory of Mind is true, then concepts are constituents of beliefs, the units of semantic evaluation, a locus of causal interactions among mental representations, and formulas in Mentalese.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.2.1)
     A reaction: I like this aspect of the theory, but then I can't really think of a theory about how the mind works that doesn't make concepts central to it.
17. Mind and Body / E. Mind as Physical / 4. Connectionism
Only the labels of nodes have semantic content in connectionism, and they play no role [Fodor]
     Full Idea: Connectionism has no truck with mental representations; on the one hand, only the node labels in 'neural networks' have semantic content, and, on the other, the node labels play no role in mental processes, in standard formulations.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.1)
     A reaction: Connectionism must have some truth in it, yet mere connections can't do the full job. The difficulty is that nothing else seems to do the 'full job' either. Fodor cites productivity, systematicity, compositionality, logical form as the problems.
18. Thought / A. Modes of Thought / 1. Thought
Associative thinking avoids syntax, but can't preserve sense, reference or truth [Fodor]
     Full Idea: The virtue of associative theories of thinking is that they don't require thoughts to have syntactic structure. But they can't be right, since association doesn't preserve either sense or reference (to say nothing of truth).
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.3 n28)
     A reaction: This is using the empiricist idea that knowledge is built from mechanical associations to give a complete account of what thinking is. Fodor resolutely opposes it.
Connectionism gives no account of how constituents make complex concepts [Fodor]
     Full Idea: Connectionist architectures provide no counterpart to the relation between a complex concept and its constituents.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.3 n29)
     A reaction: This is the compositionality of thought, upon which Fodor is so insistent. Not that a theory of how the mind is built up from the body is quite likely to give you a theory about what thinking is. I try to keep them separate, which may be wrong.
18. Thought / B. Mechanics of Thought / 4. Language of Thought
Ambiguities in English are the classic reason for claiming that we don't think in English [Fodor]
     Full Idea: That there are ambiguities in English is the classic reason for claiming that we don't think in English.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.5)
     A reaction: I have always been impressed by this simple observation, which is my main reason for believing in propositions (as brain events). 'Propositions' may just be useful chunks of mentalese.
18. Thought / B. Mechanics of Thought / 5. Mental Files
Mental representations name things in the world, but also files in our memory [Fodor]
     Full Idea: Mental representations can serve both as names for things in the world and as names of files in the memory.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3 App)
     A reaction: I am laughed at for liking this idea (given the present files of ideas before you), but I think this it is very powerful. Chicken before egg. I was drawn to databases precisely because they seemed to map how the mind worked.
We think in file names [Fodor]
     Full Idea: We think in file names.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3 App)
     A reaction: This is Fodor's new view. He cites Treisman and Schmidt (1982) for raising it, and Pylyshyn (2003) for discussing it. I love it. It exactly fits my introspective view of how I think, and I think it would fit animals. It might not fit some other people!
18. Thought / B. Mechanics of Thought / 6. Artificial Thought / a. Artificial Intelligence
Frame Problem: how to eliminate most beliefs as irrelevant, without searching them? [Fodor]
     Full Idea: The frame problem is, precisely: How does one know that none of one's beliefs about Jupiter are germane to the current question, without having to recall and search one's beliefs about Jupiter?
     From: Jerry A. Fodor (LOT 2 [2008], Ch.4.4)
     A reaction: Presumably good chess-playing computers have made some progress with this problem. The only answer, as far as I can see, is that brains have a lot in common with relational databases. The mind is structured around a relevance-pattern.
18. Thought / C. Content / 5. Twin Earth
If concept content is reference, then my Twin and I are referring to the same stuff [Fodor]
     Full Idea: If the content of a concept is its reference, we can stop worrying about Twin Earth. If there are no senses, there is no question of whether my twin and I have the same WATER concept. Our WATER concepts aren't even coextensive.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.1)
     A reaction: This seems like a neat solution. So do 'tap water' and 'holy water' have the same content to a Christian and non-Christian, when they co-refer to the contents of the font?
18. Thought / D. Concepts / 2. Origin of Concepts / a. Origin of concepts
Nobody knows how concepts are acquired [Fodor]
     Full Idea: I don't know how concepts are acquired. Nor do you. Nor does anybody else.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.5.4)
     A reaction: This comes in the context of quietly modifying his earlier claim that concepts weren't acquired, because they were largely innate. Presumably we are allowed to have theories of concept acquisition? I quite like abstractionism.
18. Thought / D. Concepts / 2. Origin of Concepts / c. Nativist concepts
We have an innate capacity to form a concept, once we have grasped the stereotype [Fodor]
     Full Idea: What's learned are stereotypes. What's innate is the disposition to grasp such and such a concept (to lock to such a property) in consequence of having learned such and such a stereotype.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.5.4)
     A reaction: This is the late Fodor much ameliorated view, after a lot of scoffing about the idea of the tin-opener being innate in all of us. There may be a suspicion of circularity here, if we ask what mental abilities are needed to form a stereotype.
18. Thought / D. Concepts / 3. Ontology of Concepts / a. Concepts as representations
Having a concept isn't a pragmatic matter, but being able to think about the concept [Fodor]
     Full Idea: Pragmatism about concepts really is dead, and the only alternative about concept possession is Cartesianism. That is, it's the thesis that having concept C is being able to think about Cs (as such).
     From: Jerry A. Fodor (LOT 2 [2008], Ch.2.2)
     A reaction: I like this. It is very hard to pick out from Fodor the bits where he is clearly right, but this seems to be one of them. I don't like the pragmatic or Wittgensteinian line that having concepts is all about abilities and uses (like sorting or inferring).
Concepts have two sides; they are files that face thought, and also face subject-matter [Fodor]
     Full Idea: We think in file names, and file names are Janus-faced: one face turned towards thinking and the other face turned towards what is thought about. I do think that is rather satisfactory.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3 App)
     A reaction: So do I. I do hope the philosophical community take up this idea (which they probably won't, simply because Fodor is in the late stages of his career!).
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
Cartesians put concept individuation before concept possession [Fodor]
     Full Idea: Cartesians think that concept individuation is prior, in order of analysis, to concept possession.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.12)
     A reaction: Peacocke is someone who seems to put possession first, to the point where individuation is thereby achieved. The background influence there is Wittgenstein. I think I am more with Fodor, that concepts are entities, which need to be understood.
18. Thought / D. Concepts / 3. Ontology of Concepts / c. Fregean concepts
Frege's puzzles suggest to many that concepts have sense as well as reference [Fodor]
     Full Idea: Philosophers in droves have held that Frege cases are convincing arguments that concepts have not just referents but also senses.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.2)
     A reaction: [Frege cases are puzzles where simple reference seems to lead to confusion] I take the Fregean approach to concepts (of Dummett, Peacocke) to attempt to give an account of the sense, once the reference is decided. Idea 12629 gives Fodor's view.
If concepts have sense, we can't see the connection to their causal powers [Fodor]
     Full Idea: How are we to understand the connection between the identity of a concept and its causal powers if concepts are (or have) senses? Answer: I haven't a clue.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.3)
     A reaction: This seems to be the key to Fodor's attack on Peacocke and other Fregeans - that while they pay lip-service to the project of naturalising thought, they are actually committing us to some sort of neo-platonism, by losing the causal links. See Idea 12636.
Belief in 'senses' may explain intentionality, but not mental processes [Fodor]
     Full Idea: Supposing the mind to be conversant with senses can, maybe, provide for a theory of the intentionality of mental states; but it seems to shed no light at all on the nature of mental processes (i.e. of mental state transitions).
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.3)
     A reaction: I would track this back to Frege's hostility to 'psychologism'. That is, Fregeans don't care about Fodor's problem, because all their accounts (of mathematics, of logic, and of concepts) treat the subject-matter as self-contained sui generis.
18. Thought / D. Concepts / 4. Structure of Concepts / a. Conceptual structure
You can't think 'brown dog' without thinking 'brown' and 'dog' [Fodor]
     Full Idea: You can think 'brown dog' without thinking 'cat', but you can't think 'brown dog' without thinking 'brown' and 'dog'.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.4.3)
     A reaction: Fodor is talking about concepts in thought, not about words. The claim is that such concepts have to be compositional, and it is hard to disagree.
18. Thought / D. Concepts / 4. Structure of Concepts / d. Concepts as prototypes
Maybe stereotypes are a stage in concept acquisition (rather than a by-product) [Fodor]
     Full Idea: We needn't say that learning a stereotype is just a by-product of acquiring the concept; it could rather be a stage in concept acquisition.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.5.4)
     A reaction: He rejects stereotypes because they don't give concepts the necessary compositionality in thought. But this idea would mean that children were incapable of compositionality until they had transcended the primitive stereotype stage.
One stereotype might be a paradigm for two difference concepts [Fodor]
     Full Idea: The same stereotype can give difference concepts; chickens are paradigmatic instances both of FOOD and of BARNYARD FOWL.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.5.4)
     A reaction: And I'm guessing that lots of concepts could have two equally plausible stereotypes, even within a single mind. Stereotypes are interesting, but they don't seem to be the key to our understanding of concepts.
18. Thought / D. Concepts / 4. Structure of Concepts / g. Conceptual atomism
For the referential view of thought, the content of a concept is just its reference [Fodor]
     Full Idea: Pure referentialism is the kind of semantics RTM requires (reference is the only primitive mind-world semantic property). ...So the content of a concept is its reference.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.1)
     A reaction: This seems to say that the meaning of a concept is (typically) a physical object, which seems to be the 'Fido'-Fido view of meaning. It seems to me to be a category mistake to say that a meaning can be a cat.
Compositionality requires that concepts be atomic [Fodor]
     Full Idea: Atomism must be right about the individuation of concepts because compositionality demands it.
     From: Jerry A. Fodor (LOT 2 [2008], Ch1)
     A reaction: I suppose this seems right, though Fodor's own example of 'pet fish' is interesting. What is supposed to happen when you take a concept like 'pet' and put it with 'fish', given that both components shift their atomic (?) meaning in the process?
18. Thought / E. Abstraction / 2. Abstracta by Selection
Abstractionism claims that instances provide criteria for what is shared [Fodor]
     Full Idea: In the idea of learning concepts by 'abstraction', experiences of the instances provide evidence about which of the shared properties of things in a concept's extension are 'criterial' for being in the concept's extension.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.5.2 n6)
     A reaction: Fodor is fairly sceptical of this approach, and his doubts are seen in the scare-quotes around 'criterial'. He is defending the idea that only a certain degree of innateness in the concepts can get such a procedure off the ground.
19. Language / A. Nature of Meaning / 7. Meaning Holism / c. Meaning by Role
'Inferential-role semantics' says meaning is determined by role in inference [Fodor]
     Full Idea: 'Inferential-role semantics' claims that the meaning of a word (/the content of a concept) is determined by its role in inference.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.2.1.2 n14)
     A reaction: Fodor is deeply opposed to this view. At first blush it sounds wrong to me, since there seems to be plenty of thought that can go on before inference takes place. Daydreamy speculation, for example.
19. Language / B. Reference / 1. Reference theories
Co-referring terms differ if they have different causal powers [Fodor]
     Full Idea: The representation of 'morning star' must be different from 'evening star' because their tokens differ in their causal powers.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.3)
     A reaction: This is Fodor trying to avoid the standard Fregean move of proposing that there are 'senses' as well as references. See Idea 12629. If these two terms have the same extension, they are the same concept? They 'seem' to have two referents.
We refer to individuals and to properties, and we use singular terms and predicates [Fodor]
     Full Idea: I assume that there are two kinds of reference: reference to individuals and to properties. This means, from the syntactic point of view, that the vehicles of reference are exhaustively singular terms and predicates.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.7)
     A reaction: The immediate possibility that comes to mind is plural quantification. See George Boolos, who confidently says that he can refer to 'some Cheerios' in his breakfast bowl, and communicate very well. He then looks to formalise such talk.
19. Language / C. Assigning Meanings / 2. Semantics
Semantics (esp. referential semantics) allows inferences from utterances to the world [Fodor]
     Full Idea: All you need for inferring from John's utterance to the world is the sort of thing that a semantics (i.e. referential semantics) provides.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.5)
     A reaction: Fodor is very good at saying nice simple things like that. But it is not enough to infer what objects are being discussed. All the hard cases must be covered (denials of existence, reference to non-existence, intentional contexts, modal claims).
Semantics relates to the world, so it is never just psychological [Fodor]
     Full Idea: Semantics is about constitutive relations between representations and the world. There is, as a matter of principle, no such thing as a psychological theory of meaning.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.3.5)
     A reaction: The second sentence is in capital letters, but I am still not convinced. The classic difficulty seems to be that you have to use language to pick out the things in the world that are being referred to. Of course, at some point you just see the objects.
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?
20. Action / C. Motives for Action / 3. Acting on Reason / a. Practical reason
Before you can plan action, you must decide on the truth of your estimate of success [Fodor]
     Full Idea: You can't think a plan of action unless you can think how the world would be if the action were to succeed; and thinking the world will be such and such if all goes well is thinking the kind of thing that can be true or false.
     From: Jerry A. Fodor (LOT 2 [2008], Ch.1)
     A reaction: This is part of Fodor's attack on the pragmatic view of concepts (that they should be fully understood in terms of action, rather than of thought). I take Fodor to be blatantly correct. This is counterfactual thinking.
23. Ethics / E. Utilitarianism / 1. Utilitarianism
Negative utilitarianism implies that the world should be destroyed, to avoid future misery [Smart]
     Full Idea: The doctrine of negative utilitarianism (that we should concern ourselves with the minimisation of suffering, rather than the maximisation of happiness) ...means we should support a tyrant who explodes the world, to prevent infinite future misery.
     From: J.J.C. Smart (Outline of a System of Utilitarianism [1973], 5)
     A reaction: That only seems to imply that the negative utilitarian rule needs supplementary rules. We are too fond of looking for one single moral rule that guides everything.
23. Ethics / E. Utilitarianism / 3. Motivation for Altruism
Any group interested in ethics must surely have a sentiment of generalised benevolence [Smart]
     Full Idea: A utilitarian can appeal to the sentiment of generalised benevolence, which is surely present in any group with whom it is profitable to discuss ethical questions.
     From: J.J.C. Smart (Outline of a System of Utilitarianism [1973], I)
     A reaction: But ethics is not intended only for those who are interested in ethics. If this is the basics of ethics, then we must leave the mafia to pursue its sordid activities without criticism. Their lack of sympathy seems to be their good fortune.