19 ideas
| 15647 | 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. |
| 15649 | 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. |
| 15655 | 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] |
| 15654 | 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. |
| 15650 | 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) |
| 15648 | 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. |
| 15656 | 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'. |
| 15657 | 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) |
| 15652 | 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. |
| 15651 | 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. |
| 20945 | Belief is no more rational than is tasting and smelling [Hamann] |
| Full Idea: Belief happens as little in terms of reasons as tasting and smelling. | |
| From: J.G. Hamann (works [1770], v2:74), quoted by Andrew Bowie - Introduction to German Philosophy | |
| A reaction: That is one idea definitively expressed! I take it as only a partial truth. Beliefs happen as a result of observation and experience. But someone can draw our attention to something (and we can hunt it out ourselves), which is giving a reason for belief. |
| 9264 | Persons are distinguished by a capacity for second-order desires [Frankfurt] |
| Full Idea: The essential difference between persons and other creatures is in the structure of the will, with their peculiar characteristic of being able to form 'second-order desires'. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], Intro) | |
| A reaction: There are problems with this - notably that all strategies of this kind just shift the problem up to the next order, without solving it - but this still strikes me as a very promising line of thinking when trying to understand ourselves. See Idea 9266. |
| 9266 | A person essentially has second-order volitions, and not just second-order desires [Frankfurt] |
| Full Idea: It is having second-order volitions, and not having second-order desires generally, that I regard as essential to being a person. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §II) | |
| A reaction: Watson criticises Frankfurt for just pushing the problem up to the the next level, but Frankfurt is not offering to explain the will. He merely notes that this structure produces the sort of behaviour which is characteristic of persons, and he is right. |
| 9267 | Free will is the capacity to choose what sort of will you have [Frankfurt] |
| Full Idea: The statement that a person enjoys freedom of the will means that he is free to want what he wants to want. More precisely, he is free to will what he wants to will, or to have the will he wants. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §III) | |
| A reaction: A good proposal. It covers kleptomaniacs and drug addicts quite well. Thieves have second-order desires (to steal) of which kleptomaniacs are incapable. There is actually no such thing as free will, but this sort of thing will do. |
| 9265 | The will is the effective desire which actually leads to an action [Frankfurt] |
| Full Idea: A person's will is the effective desire which moves (or will or would move) a person all the way to action. The will is not coextensive with what an agent intends to do, since he may do something else instead. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §I) | |
| A reaction: Essentially Hobbes's view, but with an arbitrary distinction added. If the desire is only definitely a 'will' if it really does lead to action, then it only becomes the will after the action starts. The error is thinking that will is all-or-nothing. |
| 20015 | Freedom of action needs the agent to identify with their reason for acting [Frankfurt, by Wilson/Schpall] |
| Full Idea: Frankfurt says that basic issues concerning freedom of action presuppose and give weight to a concept of 'acting on a desire with which the agent identifies'. | |
| From: report of Harry G. Frankfurt (Freedom of the Will and concept of a person [1971]) by Wilson,G/Schpall,S - Action 1 | |
| A reaction: [the cite Frankfurt 1988 and 1999] I'm not sure how that works when performing a grim duty, but it sounds quite plausible. |
| 9270 | A 'wanton' is not a person, because they lack second-order volitions [Frankfurt] |
| Full Idea: I use the term 'wanton' to refer to agents who have first-order desires but who are not persons because, whether or not they have desires of the second-order, they have no second-order volitions. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §II) | |
| A reaction: He seems to be describing someone who behaves like an animal, performing actions without ever stopping to think about them. Presumably some persons occasionally become wantons, if, for example, they have an anger problem. |
| 9269 | A person may be morally responsible without free will [Frankfurt] |
| Full Idea: It is not true that a person is morally responsible for what he has done only if his will was free when he did it. He may be morally responsible for having done it even though his will was not free at all. | |
| From: Harry G. Frankfurt (Freedom of the Will and concept of a person [1971], §IV) | |
| A reaction: Frankfurt seems to be one of the first to assert this break with the traditional view. Good for him. I take moral responsibility to hinge on an action being caused by a person, but not with a mystical view of what a person is. |
| 7666 | God is not a mathematician, but a poet [Hamann, by Berlin] |
| Full Idea: Hamann's fundamental doctrine was that God was not a geometer, not a mathematician, but a poet. | |
| From: report of J.G. Hamann (works [1770]) by Isaiah Berlin - The Roots of Romanticism Ch.3 | |
| A reaction: [This idea is wonderfully expressed by D.H.Lawrence in his poem 'Red Geranium and Godly Mignonette]. The idea becomes attractive when you ask whether God would need to do mathematics. |