20 ideas
| 15118 | A successful Aristotelian 'definition' is what sciences produces after an investigation [Koslicki] |
| Full Idea: My current use of the Aristotelian term 'definition' is intended to correspond to what is typically accessible to a scientist only at the end of a successful investigation into the nature of a particular phenomenon. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.3.1) | |
| A reaction: It is crucial to understand that Aristotle's definitions could be several hundred pages long. It has nothing to do with dictionary definitions. He proposes 'nominal' and 'real' definitions. |
| 15116 | Essences cause necessary features, and definitions describe those necessary features [Koslicki] |
| Full Idea: Since essences cause the other necessary features of a thing, so definitions, as the linguistic correlates of essences, explain, together with other axioms, the propositions describing those necessary features. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.3.1) | |
| A reaction: This is nice and clear. Definitions are NOT essences - they are the linguistic correlates of essences, and mirror those essences. The necessary features are not the only things needing explanation. That picture is too passive. |
| 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. |
| 15110 | An essence and what merely follow from it are distinct [Koslicki] |
| Full Idea: We can distinguish (as Aristotle and Fine do) between what belongs to the essence of an object, and what merely follows from the essence of an object. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.1) | |
| A reaction: This can help to clarify the confusions that result from treating necessary properties as if they were essential. |
| 15113 | Individuals are perceived, but demonstration and definition require universals [Koslicki] |
| Full Idea: Individual instances of a kind of phenomenon, in Aristotle's view, can only be perceived through sense-perception; but they are not the proper subject-matter of scientific demonstration and definition. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.3.1) | |
| A reaction: A footnote (11) explains that this is because they involve syllogisms, which require universals. I take Aristotle, and anyone sensible, to rest on individual essences, but inevitably turn to generic essences when language becomes involved. |
| 15112 | If an object exists, then its essential properties are necessary [Koslicki] |
| Full Idea: If an object has a certain property essentially, then it follows that the object has the property necessarily (if it exists). | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.2) | |
| A reaction: She is citing Fine, who says that the converse (necessity implying essence) is false. I agree with that. I also willing to challenge the first bit. I suspect an object can retain identity and lose essence. Coma patient; broken clock; aged athlete. |
| 8875 | Sense experiences must have conceptual content, since they are possible reasons for judgements [Brewer,B] |
| Full Idea: Given that sense experiential states do provide reasons for empirical beliefs, they must have conceptual content, ...where a mental state with conceptual content is one where the content is of a possible judgement by the subject. | |
| From: Bill Brewer (Perceptual experience has conceptual content [2005], I) | |
| A reaction: This is, I believe, wrong. Even complex observations, like a pool of blood, only become reasons when they have been interpreted. Otherwise they are just the raw ingredients of evidence. How could an uninterpreted red patch be a 'reason'? |
| 15111 | In demonstration, the explanatory order must mirror the causal order of the phenomena [Koslicki] |
| Full Idea: Demonstration encompasses more than deductive entailment, in that the explanatory order of priority represented in a successful demonstration must mirror precisely the causal order of priority present in the phenomena in question. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.1) | |
| A reaction: She is referring to Aristotle's 'Posterior Analytics'. Put so clearly this sounds like an incredibly useful concept in discussing how we present good modern scientific explanations. Reinstating Aristotle is a major priority for philosophy! |
| 15115 | In a demonstration the middle term explains, by being part of the definition [Koslicki] |
| Full Idea: In a proper demonstrative argument, the middle term must be explanatory of the conclusion, in a very specific sense: the middle term must state what properly belongs to the definition of the kind of phenomenon in question. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.3.1) | |
| A reaction: So 'All men are mortal, S is a man, so S is mortal'. The middle term is 'man', which gives a generic explanation for why S is mortal. Explanation as categorisation? I don't think this is the whole story of Aristotelian explanation. |
| 15117 | Greek uses the same word for 'cause' and 'explanation' [Koslicki] |
| Full Idea: The Greek does not disambiguate between 'cause' and 'explanation', since the same terms ('aitia' and 'aition') can be translated in both ways. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.3.1 n15) | |
| A reaction: This is essential information if we are to understand Aristotle's Four Causes, which are quite baffling if we take 'causes' in the modern way. The are the Four Modes of Explanation. |
| 15114 | Discovering the Aristotelian essence of thunder will tell us why thunder occurs [Koslicki] |
| Full Idea: Both the question 'what is thunder?', and the question 'why does thunder occur?', for Aristotle, are answered simultaneously, once it has been discovered what the essence of thunder it, i.e. what it is to be thunder. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.3.1 n10) | |
| A reaction: I take this idea to be pretty much the whole story about essences. |