18 ideas
| 9271 | Human knowledge may not produce well-being; the examined life may not be worth living [Gray] |
| Full Idea: Human knowledge is one thing, human well-being another. There is no predetermined harmony between the two. The examined life may not be worth living. | |
| From: John Gray (Straw Dogs [2002], 1.9) | |
| A reaction: John Gray has set himself up as the Eeyore of modern times, but this point may obviously be correct. Presumably Socrates meant that the examined life was better even if the result was less 'well-being'. Even Gray doesn't want a lobotomy. |
| 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. |
| 18702 | Names, descriptions and predicates refer to things; without that, language and thought are baffling [Davidson] |
| Full Idea: The simple thesis that names and descriptions often refer to things, and that predicates often have an extension in the world of things, is obvious, and essential to the most elementary appreciation of both language and the thoughts we express. | |
| From: Donald Davidson (Replies to Critics [1998], p.323) | |
| A reaction: In 1983 Davidson had been a rare modern champion of the coherence theory of truth, but this is his clearest later renunciation of that view (and quite right too). |
| 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. |
| 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. |
| 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) |
| 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. |
| 9275 | Knowledge does not need minds or nervous systems; it is found in all living things [Gray] |
| Full Idea: Knowledge does not need minds, or even nervous systems. It is found in all living things. | |
| From: John Gray (Straw Dogs [2002], 2.10) | |
| A reaction: I consider it a misnomer to call such things 'knowledge', for which I have much higher standards. Gray is talking about 'information'. Knowledge needs reasons, and possibility of error, not just anticipatory behaviour. |
| 9276 | The will hardly ever does anything; most of our life just happens to us [Gray] |
| Full Idea: We think our actions express our decisions, but in nearly all of our life, willing decides nothing. We cannot wake up or fall asleep, remember or forget our dreams, summon or banish our thoughts, by deciding to do so. | |
| From: John Gray (Straw Dogs [2002], 2.12) | |
| A reaction: Gray's point does not rule out occasional total control over mental life, but his point is important. The traditional picture is of a life controlled, so the will is seen as at the centre of a person, but it just isn't the case. |
| 9278 | Nowadays we identify the free life with the good life [Gray] |
| Full Idea: We do not value freedom more than people did in earlier times, but we have identified the good life with the chosen life. | |
| From: John Gray (Straw Dogs [2002], 3.13) | |
| A reaction: Interesting. This is Enlightenment liberalism gradually filtering down into common consciousness, especially via the hegemony of American culture. I sympathise the Gray; don't get me wrong, but I think freedom is overrated. |
| 9280 | Over forty percent of the Earth's living tissue is human [Gray] |
| Full Idea: Humans co-opt over forty per cent of the Earth's living tissue. | |
| From: John Gray (Straw Dogs [2002], 4.15) | |
| A reaction: If you add our domestic animals, I understand that the figure goes up to 95 per cent! I take this to be virtually the only significant ecological fact - population, population, population. Why are there so many cars? So many carbon footprints? |
| 9279 | What was our original sin, and how could Christ's suffering redeem it? [Gray] |
| Full Idea: No one can say what was humankind's original sin, and no one understands how the suffering of Christ can redeem it. | |
| From: John Gray (Straw Dogs [2002], 4.1) | |
| A reaction: This nicely articulates a problem that has half bothered me, but I have never put into words. I always assumed Eve committed the sin, and Adam cops the blame for not controlling his woman. Dying for our sins has always puzzled me. |
| 9272 | Without Christianity we lose the idea that human history has a meaning [Gray] |
| Full Idea: For Christians, it is because they occur in history that the lives of humans have a meaning that the lives of other animals do not. ..If we truly leave Christianity behind, we must give up the idea that human history has a meaning. | |
| From: John Gray (Straw Dogs [2002], 2.3) | |
| A reaction: Interesting. Compare the dispute between 'whig' and 'tory' historians, the former of whom believe that history is going somewhere. |