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All the ideas for 'Axiomatic Theories of Truth (2005 ver)', 'Value Theory' and 'The Nature of Mathematics'

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32 ideas

1. Philosophy / G. Scientific Philosophy / 3. Scientism
Philosophy is an experimental science, resting on common experience [Peirce]
     Full Idea: Philosophy, although it uses no microscopes or other apparatus of special observation, is really an experimental science, resting on that experience which is common to us all.
     From: Charles Sanders Peirce (The Nature of Mathematics [1898], I)
     A reaction: The 'experimental' either implies that thought-experiments are central to the subject, or that philosophers are discussing the findings of scientists, but at a high level of theory and abstraction. Peirce probably means the latter. I can't disagree.
2. Reason / B. Laws of Thought / 3. Non-Contradiction
Self-contradiction doesn't reveal impossibility; it is inductive impossibility which reveals self-contradiction [Peirce]
     Full Idea: It is an anacoluthon to say that a proposition is impossible because it is self-contradictory. It rather is thought so to appear self-contradictory because the ideal induction has shown it to be impossible.
     From: Charles Sanders Peirce (The Nature of Mathematics [1898], III)
3. Truth / A. Truth Problems / 2. Defining Truth
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.
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.
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
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.
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.
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)
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
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'.
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)
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 / C. Ontology of Logic / 3. If-Thenism
Logic, unlike mathematics, is not hypothetical; it asserts categorical ends from hypothetical means [Peirce]
     Full Idea: Mathematics is purely hypothetical: it produces nothing but conditional propositions. Logic, on the contrary, is categorical in its assertions. True, it is a normative science, and not a mere discovery of what really is. It discovers ends from means.
     From: Charles Sanders Peirce (The Nature of Mathematics [1898], II)
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.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
Mathematics is close to logic, but is even more abstract [Peirce]
     Full Idea: The whole of the theory of numbers belongs to logic; or rather, it would do so, were it not, as pure mathematics, pre-logical, that is, even more abstract than logic.
     From: Charles Sanders Peirce (The Nature of Mathematics [1898], IV)
     A reaction: Peirce seems to flirt with logicism, but rejects in favour of some subtler relationship. I just don't believe that numbers are purely logical entities.
7. Existence / C. Structure of Existence / 5. Supervenience / a. Nature of supervenience
To avoid misunderstandings supervenience is often expressed negatively: no A-change without B-change [Orsi]
     Full Idea: It is no part of supervenience that 'if p then q' entails 'if not p then not q'. To avoid such misunderstandings, it is common (though not more accurate) to describe supervenience in negative terms: no difference in A without a difference in B.
     From: Francesco Orsi (Value Theory [2015], 5.2)
     A reaction: [compressed] In other words it is important to avoid the presupposition that the given supervenience is a two-way relation. The paradigm case of supervenience is stalking.
10. Modality / B. Possibility / 1. Possibility
Some logical possibility concerns single propositions, but there is also compatibility between propositions [Peirce]
     Full Idea: Many say everything is logically possible which involves no contradiction. In this sense two contradictory propositions may be severally possible. In the substantive sense, the contradictory of a possible proposition is impossible (if we were omniscient).
     From: Charles Sanders Peirce (The Nature of Mathematics [1898], III)
12. Knowledge Sources / D. Empiricism / 1. Empiricism
Experience is indeed our only source of knowledge, provided we include inner experience [Peirce]
     Full Idea: If Mill says that experience is the only source of any kind of knowledge, I grant it at once, provided only that by experience he means personal history, life. But if he wants me to admit that inner experience is nothing, he asks what cannot be granted.
     From: Charles Sanders Peirce (The Nature of Mathematics [1898])
     A reaction: Notice from Idea 14785 that Peirce has ideas in mind, and not just inner experiences like hunger. Empiricism certainly begins to look more plausible if we expand the notion of experience. It must include what we learned from prior experience.
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
The world is one of experience, but experiences are always located among our ideas [Peirce]
     Full Idea: The real world is the world of sensible experience, and it is part of the process of sensible experience to locate its facts in the world of ideas.
     From: Charles Sanders Peirce (The Nature of Mathematics [1898], III)
     A reaction: This is the neatest demolition of the sharp dividing line between empiricism and rationalism that I have ever encountered.
20. Action / C. Motives for Action / 3. Acting on Reason / c. Reasons as causes
Rather than requiring an action, a reason may 'entice' us, or be 'eligible', or 'justify' it [Orsi]
     Full Idea: Many have suggested alternative roles or sorts of reasons, which are not mandatory. Dancy says some reasons are 'enticing' rather than peremptory; Raz makes options 'eligible' rather than required; Gert says they justify rather than require action.
     From: Francesco Orsi (Value Theory [2015], 6.4)
     A reaction: The third option is immediately attractive - but then it would only justify the action because it was a good reason, which would need explaining. 'Enticing' captures the psychology in a nice vague way.
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / b. Defining ethics
Ethics is the science of aims [Peirce]
     Full Idea: Ethics is the science of aims.
     From: Charles Sanders Peirce (The Nature of Mathematics [1898], II)
     A reaction: Intriguing slogan. He is discussing the aims of logic. I think what he means is that ethics is the science of value. 'Science' may be optimistic, but I would sort of agree with his basic idea.
22. Metaethics / B. Value / 1. Nature of Value / a. Nature of value
Final value is favoured for its own sake, and personal value for someone's sake [Orsi]
     Full Idea: Final value is to be favoured for its own sake; personal value is to be favoured for someone's sake.
     From: Francesco Orsi (Value Theory [2015], 7.2)
     A reaction: This gives another important dimension for discussions of value. I like the question 'what gives rise to this value?', but we can also ask (given the value) why we should then promote it. Health isn't a final value, and truth isn't a personal value?
Value-maker concepts (such as courageous or elegant) simultaneously describe and evaluate [Orsi]
     Full Idea: Examples of value-maker concepts are courageous, honest, cowardly, corrupt, elegant, tacky, melodious, insightful. Employing these concepts normally means both evaluating and describing the thing or person one way or another.
     From: Francesco Orsi (Value Theory [2015], 1.2)
     A reaction: The point being that they tell you two things - that this thing has a particular value, and also why it has that value. Since I am flirting with the theory that all values must have 'value-makers' this is very interesting.
The '-able' concepts (like enviable) say this thing deserves a particular response [Orsi]
     Full Idea: The '-able' concepts, such as valuable, enviable, contemptible, wear on their sleeve the idea that the thing so evaluated merits or is worth a certain attitude or response (of valuing, envying, despising).
     From: Francesco Orsi (Value Theory [2015], 1.2)
     A reaction: Compare Idea 18666. Hence some concepts point to the source of value in the thing, and others point to the source of the value in the normative attitude of the speaker. Interesting.
Things are only valuable if something makes it valuable, and we can ask for the reason [Orsi]
     Full Idea: If a certain object is valuable, then something other than its being valuable must make it so. ...One is always in principle entitled to an answer as to why it is good or bad.
     From: Francesco Orsi (Value Theory [2015], 5.2)
     A reaction: What Orsi calls the 'chemistry' of value. I am inclined to think that this is the key to a philosophical study of value. Without this assumption the values float free, and we drift into idealised waffle. Note that here he only refers to 'objects'.
A complex value is not just the sum of the values of the parts [Orsi]
     Full Idea: The whole 'being pleased by cats being tortured' is definitely not better, and is likely worse, than cats being tortured. So its value cannot result from a sum of the intrinsic values of the parts.
     From: Francesco Orsi (Value Theory [2015], 5.3)
     A reaction: This example is simplistic. It isn't a matter of just adding 'pleased' and 'tortured'. 'Pleased' doesn't have a standalone value. Only a rather gormless utilitarian would think it was always good if someone was pleased. I suspect values don't sum at all.
Trichotomy Thesis: comparable values must be better, worse or the same [Orsi]
     Full Idea: It is natural to assume that if we can compare two objects or states of affairs, X and Y, then X is either better than, or worse than, or as good as Y. This has been called the Trichotomy Thesis.
     From: Francesco Orsi (Value Theory [2015], 6.2)
     A reaction: This is the obvious starting point for a discussion of the difficult question of the extent to which values can be compared. Orsi says even if there was only one value, like pleasure, it might have incommensurable aspects like duration and intensity.
The Fitting Attitude view says values are fitting or reasonable, and values are just byproducts [Orsi]
     Full Idea: The main claims of the Fitting Attitude view of value are Reduction: values such are goodness are reduced to fitting attitudes, having reasons, and Normative Redundancy: goodness provides no reasons for attitudes beyond the thing's features.
     From: Francesco Orsi (Value Theory [2015], 8.2)
     A reaction: Orsi's book is a sustained defence of this claim. I like the Normative Redundancy idea, but I am less persuaded by the Reduction.
22. Metaethics / B. Value / 1. Nature of Value / c. Objective value
Values from reasons has the 'wrong kind of reason' problem - admiration arising from fear [Orsi]
     Full Idea: A support for the fittingness account (against the buck-passing reasons account) is the 'wrong kind of reasons' problem. There are many reasons for positive attitudes towards things which are not good. We might admire a demon because he threatens torture.
     From: Francesco Orsi (Value Theory [2015], 1.4)
     A reaction: [compressed] I like the Buck-Passing view, but was never going to claim that all reasons for positive attitudes bestow value. I only think that there is no value without a reason
22. Metaethics / B. Value / 1. Nature of Value / f. Ultimate value
A thing may have final value, which is still derived from other values, or from relations [Orsi]
     Full Idea: Many believe that final values can be extrinsic: objects which are valuable for their own sake partly thanks to their relations to other objects. ...This might depend on the value of other things...or an object's relational properties.
     From: Francesco Orsi (Value Theory [2015], 2.3)
     A reaction: It strikes me that virtually nothing (or even absolutely nothing) has final value in total isolation from other things (Moore's 'isolation test'). Values arise within a tangled network of relations. Your final value is my instrumental value.
22. Metaethics / B. Value / 2. Values / a. Normativity
Truths about value entail normative truths about actions or attitudes [Orsi]
     Full Idea: My guiding assumption is that truths about value, at least, regularly entail normative truths of some sort about actions or attitudes.
     From: Francesco Orsi (Value Theory [2015], 1.4)
     A reaction: Not quite as clear as it sounds. If I say 'the leaf is green' I presume a belief that it is green, which is an attitude. If I say 'shut the door' that implies an action with no value. One view says that values are entirely normative in this way.
The Buck-Passing view of normative values says other properties are reasons for the value [Orsi]
     Full Idea: Version two of the normative view of values is the Buck-Passing account, which says that 'x is good' means 'x has the property of having other properties that provide reasons to favour x'.
     From: Francesco Orsi (Value Theory [2015], 1.4)
     A reaction: [He cites Scanlon 1998:95-8] I think this is the one to explore. We want values in the world, bridging the supposed 'is-ought gap', and not values that just derive from the way human beings are constituted (and certainly not supernatural values!).
Values can be normative in the Fitting Attitude account, where 'good' means fitting favouring [Orsi]
     Full Idea: Version one of the normative view of values is the Fitting Attitude account, which says that 'x is good' means 'it is fitting to respond favourably to (or 'favour') x'.
     From: Francesco Orsi (Value Theory [2015], 1.4)
     A reaction: Brentano is mentioned. Orsi favours this view. The rival normative view is Scanlon's [1998:95-8] Buck-Passing account, in Idea 18670. I am interested in building a defence of the Buck-Passing account, which seems to suit a naturalistic realist like me.