38 ideas
| 19199 | Some say metaphysics is a highly generalised empirical study of objects [Tarski] |
| Full Idea: For some people metaphysics is a general theory of objects (ontology) - a discipline which is to be developed in a purely empirical way, and which differs from other empirical disciplines in its generality. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 19) | |
| A reaction: Tarski says some people despise it, but for him such metaphysics is 'not objectionable'. I subscribe to this view, but the empirical aspect is very remote, because it's too general for detail observation or experiment. Generality is the key to philosophy. |
| 19193 | Disputes that fail to use precise scientific terminology are all meaningless [Tarski] |
| Full Idea: Disputes like the vague one about 'the right conception of truth' occur in all domains where, instead of exact, scientific terminology, common language with its vagueness and ambiguity is used; and they are always meaningless, and therefore in vain. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 14) | |
| A reaction: Taski taught a large number of famous philosophers in California in the 1950s, and this approach has had a huge influence. Recently there has been a bit of a rebellion. E.g. Kit Fine doesn't think it can all be done in formal languages. |
| 19179 | For a definition we need the words or concepts used, the rules, and the structure of the language [Tarski] |
| Full Idea: We must specify the words or concepts which we wish to use in defining the notion of truth; and we must also give the formal rules to which the definition should conform. More generally, we must describe the formal structure of the language. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 01) | |
| A reaction: This, of course, is a highly formal view of how definition should be achieved, offered in anticipation of one of the most famous definitions in logic (of truth, by Tarski). Normally we assume English and classical logic. |
| 9355 | One sort of circularity presupposes a premise, the other presupposes a rule being used [Braithwaite, by Devitt] |
| Full Idea: An argument is 'premise-circular' if it aims to establish a conclusion that is assumed as a premise of that very argument. An argument is 'rule-circular' if it aims to establish a conclusion that asserts the goodness of the rule used in that argument. | |
| From: report of R.B. Braithwaite (Scientific Explanation [1953], p.274-8) by Michael Devitt - There is no a Priori §2 | |
| A reaction: Rule circularity is the sort of thing Quine is always objecting to, but such circularities may be unavoidable, and even totally benign. All the good things in life form a mutually supporting team. |
| 19178 | Definitions of truth should not introduce a new version of the concept, but capture the old one [Tarski] |
| Full Idea: The desired definition of truth does not aim to specify the meaning of a familiar word used to denote a novel notion; on the contrary, it aims to catch hold of the actual meaning of an old notion. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 01) | |
| A reaction: Tarski refers back to Aristotle for an account of the 'old notion'. To many the definition of Tarski looks very weird, so it is important to see that he is trying to capture the original concept. |
| 19177 | A definition of truth should be materially adequate and formally correct [Tarski] |
| Full Idea: The main problem of the notion of truth is to give a satisfactory definition which is materially adequate and formally correct. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 01) | |
| A reaction: That is, I take it, that it covers all cases of being true and failing to be true, and it fits in with the logic. The logic is explicitly classical logic, and he is not aiming to give the 'nature' or natural language understanding of the concept. |
| 19186 | A rigorous definition of truth is only possible in an exactly specified language [Tarski] |
| Full Idea: The problem of the definition of truth obtains a precise meaning and can be solved in a rigorous way only for those languages whose structure has been exactly specified. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 06) | |
| A reaction: Taski has just stated how to exactly specify the structure of a language. He says definition can only be vague and approximate for natural languages. (The usual criticism of the correspondence theory is its vagueness). |
| 19194 | We may eventually need to split the word 'true' into several less ambiguous terms [Tarski] |
| Full Idea: A time may come when we find ourselves confronted with several incompatible, but equally clear and precise, conceptions of truth. It will then become necessary to abandon the ambiguous usage of the word 'true', and introduce several terms instead. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 14) | |
| A reaction: There may be a whiff of the pragmatic attitude to truth here, though that view is not necessarily pluralist. Analytic philosophy needs much more splitting of difficult terms into several more focused terms. |
| 19196 | Scheme (T) is not a definition of truth [Tarski] |
| Full Idea: It is a mistake to regard scheme (T) as a definition of truth. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 15) | |
| A reaction: The point is, I take it, that the definition is the multitude of sentences which are generated by the schema, not the schema itself. |
| 19180 | It is convenient to attach 'true' to sentences, and hence the language must be specified [Tarski] |
| Full Idea: For several reasons it appears most convenient to apply the term 'true' to sentences, and we shall follow this course. Consequently, we must always relate the notion of truth, like that of a sentence, to a specific language. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 02) | |
| A reaction: Personally I take truth to attach to propositions, since sentences are ambiguous. In Idea 17308 the one sentence expresses three different truths (in my opinion), even though a single sentence (given in the object language) specifies it. |
| 19181 | In the classical concept of truth, 'snow is white' is true if snow is white [Tarski] |
| Full Idea: If we base ourselves on the classical conception of truth, we shall say that the sentence 'snow is white' is true if snow is white, and it is false if snow is not white. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 04) | |
| A reaction: I had not realised, prior to his, how closely Tarski is sticking to Aristotle's famous formulation of truth. The point is that you can only specify 'what is' using a language. Putting 'true' in the metalanguage gives specific content to Aristotle. |
| 19183 | Each interpreted T-sentence is a partial definition of truth; the whole definition is their conjunction [Tarski] |
| Full Idea: In 'X is true iff p' if we replace X by the name of a sentence and p by a particular sentence this can be considered a partial definition of truth. The whole definition has to be ...a logical conjunction of all these partial definitions. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 04) | |
| A reaction: This seems an unprecedented and odd way to define something. Define 'red' by '"This tomato is red" iff this tomato is red', etc? Define 'stone' by collecting together all the stones? The complex T-sentences are infinite in number. |
| 19182 | Use 'true' so that all T-sentences can be asserted, and the definition will then be 'adequate' [Tarski] |
| Full Idea: We wish to use the term 'true' in such a way that all the equivalences of the form (T) [i.e. X is true iff p] can be asserted, and we shall call a definition of truth 'adequate' if all these equivalences follow from it. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 04) | |
| A reaction: The interpretation of Tarski's theory is difficult. From this I'm thinking that 'true' is simply being defined as 'assertible'. This is the status of each line in a logical proof, if there is a semantic dimension to the proof (and not mere syntax). |
| 19198 | We don't give conditions for asserting 'snow is white'; just that assertion implies 'snow is white' is true [Tarski] |
| Full Idea: Semantic truth implies nothing regarding the conditions under which 'snow is white' can be asserted. It implies only that, whenever we assert or reject this sentence, we must be ready to assert or reject the correlated sentence '"snow is white" is true'. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 18) | |
| A reaction: This appears to identify truth with assertibility, which is pretty much what modern pragmatists say. How do you distinguish 'genuine' assertion from rhetorical, teasing or lying assertions? Genuine assertion implies truth? Hm. |
| 19184 | The best truth definition involves other semantic notions, like satisfaction (relating terms and objects) [Tarski] |
| Full Idea: It turns out that the simplest and most natural way of obtaining an exact definition of truth is one which involves the use of other semantic notions, e.g. the notion of satisfaction (...which expresses relations between expressions and objects). | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 05) | |
| A reaction: While the T-sentences appear to be 'minimal' and 'deflationary', it seems important to remember that 'satisfaction', which is basic to his theory, is a very robust notion. He actually mentions 'objects'. But see Idea 19185. |
| 19191 | Specify satisfaction for simple sentences, then compounds; true sentences are satisfied by all objects [Tarski] |
| Full Idea: To define satisfaction we indicate which objects satisfy the simplest sentential functions, then state the conditions for compound functions. This applies automatically to sentences (with no free variables) so a true sentence is satisfied by all objects. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 11) | |
| A reaction: I presume nothing in the domain of objects can conflict with a sentence that has been satisfied by some of them, so 'all' the objects satisfy the sentence. Tarski doesn't use the word 'domain'. Basic satisfaction seems to be stipulated. |
| 19188 | We can't use a semantically closed language, or ditch our logic, so a meta-language is needed [Tarski] |
| Full Idea: In a 'semantically closed' language all sentences which determine the adequate usage of 'true' can be asserted in the language. ...We can't change our logic, so we reject such languages. ...So must use two different languages to discuss truth. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 08-09) | |
| A reaction: This section explains why a meta-language is required. It rests entirely on the existence of the Liar paradox is a semantically closed language. |
| 19189 | The metalanguage must contain the object language, logic, and defined semantics [Tarski] |
| Full Idea: Every sentence which occurs in the object language must also occur in the metalanguage, or can be translated into the metalanguage. There must also be logical terms, ...and semantic terms can only be introduced in the metalanguage by definition. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 09) | |
| A reaction: He suggest that if the languages are 'typed', the meta-languag, to be 'richer', must contain variables of a higher logica type. Does this mean second-order logic? |
| 10824 | If listing equivalences is a reduction of truth, witchcraft is just a list of witch-victim pairs [Field,H on Tarski] |
| Full Idea: By similar standards of reduction to Tarski's, one might prove witchcraft compatible with physicalism, as long as witches cast only a finite number of spells. We merely list witch-and-victim pairs, with no mention of the terms of witchcraft theory. | |
| From: comment on Alfred Tarski (The Semantic Conception of Truth [1944], 04) by Hartry Field - Tarski's Theory of Truth §4 |
| 19190 | We need an undefined term 'true' in the meta-language, specified by axioms [Tarski] |
| Full Idea: We have to include the term 'true', or some other semantic term, in the list of undefined terms of the meta-language, and to express fundamental properties of the notion of truth in a series of axioms. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 10) | |
| A reaction: It sounds as if Tarski semantic theory gives truth for the object language, but then an axiomatic theory of truth is also needed for the metalanguage. Halbch and Horsten seem to want an axiomatic theory in the object language. |
| 19197 | Truth can't be eliminated from universal claims, or from particular unspecified claims [Tarski] |
| Full Idea: Truth can't be eliminated from universal statements saying all sentences of a certain type are true, or from the proof that 'all consequences of true sentences are true'. It is also needed if we can't name the sentence ('Plato's first sentence is true'). | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 16) | |
| A reaction: This points to the deflationary view of truth, if its only role is in talking about other sentences in this way. Tarski gives the standard reason for rejecting the Redundancy view. |
| 19185 | Semantics is a very modest discipline which solves no real problems [Tarski] |
| Full Idea: Semantics as it is conceived in this paper is a sober and modest discipline which has no pretensions to being a universal patent-medicine for all the ills and diseases of mankind, whether imaginary or real. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 05) | |
| A reaction: Written in 1944. This remark encourages the minimal or deflationary interpretation of his theory of truth, but see the robust use of 'satisfaction' in Idea 19184. |
| 19195 | Truth tables give prior conditions for logic, but are outside the system, and not definitions [Tarski] |
| Full Idea: Logical sentences are often assigned preliminary conditions under which they are true or false (often given as truth tables). However, these are outside the system of logic, and should not be regarded as definitions of the terms involved. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 15) | |
| A reaction: Hence, presumably, the connectives are primitives (with no nature or meaning), and the truth tables are axioms for their use? This opinion of Tarski's may have helped shift the preference towards natural deduction introduction and elimination rules. |
| 19192 | The truth definition proves semantic contradiction and excluded middle laws (not the logic laws) [Tarski] |
| Full Idea: With our definition of truth we can prove the laws of contradiction and excluded middle. These semantic laws should not be identified with the related logical laws, which belong to the sentential calculus, and do not involve 'true' at all. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 12) | |
| A reaction: Very illuminating. I wish modern thinkers could be so clear about this matter. The logic contains 'P or not-P'. The semantics contains 'P is either true or false'. Critics say Tarski has presupposed 'classical' logic. |
| 19187 | The Liar makes us assert a false sentence, so it must be taken seriously [Tarski] |
| Full Idea: In my judgement, it would be quite wrong and dangerous from the point of view of scientific progress to depreciate the importance of nhtinomies like the Liar Paradox, and treat them as jokes. The fact is we have been compelled to assert a false sentence. | |
| From: Alfred Tarski (The Semantic Conception of Truth [1944], 07) | |
| A reaction: This is the heartfelt cry of the perfectionist, who wants everything under control. It was the dream of the age of Frege to Hilbert, which gradually eroded after Gödel's Incompleteness proof. Short ordinary folk panic about the Liar? |
| 4983 | There are no rules linking thought and behaviour, because endless other thoughts intervene [Davidson] |
| Full Idea: We know too much about thought and behaviour to trust exact and universal statements linking them. Beliefs and desires issue in behaviour only as modified and mediated by further beliefs and desires, attitudes and attendings, without limit. | |
| From: Donald Davidson (Mental Events [1970], p.217) | |
| A reaction: Now seen as a key objection to behaviourism, and rightly so. However, I am not sure about "without limit", which implies an implausible absolute metaphysical freedom. Davidson goes too far in denying any nomological link between thought and brain. |
| 3529 | Reduction is impossible because mind is holistic and brain isn't [Davidson, by Maslin] |
| Full Idea: Davidson rejects ontological reduction of mental to physical because propositional attitudes are holistic; there must be extensive coherence among someone's attitudes to treat them as a rational person, and this has no counterpart in physical theory. | |
| From: report of Donald Davidson (Mental Events [1970]) by Keith T. Maslin - Introduction to the Philosophy of Mind 7.5 | |
| A reaction: I don't find this view persuasive. We treat the weather in simple terms, even though it is almost infinitely complex. Davidson has a Kantian overconfidence in our rationality. A coherence among the parts is needed to be a tree. |
| 2307 | Anomalous monism says nothing at all about the relationship between mental and physical [Davidson, by Kim] |
| Full Idea: Davidson's anomalous monism says no more about the relationship between the mental and the physical than the claim that all objects with a colour have a shape says about the relationship between colours and shapes. | |
| From: report of Donald Davidson (Mental Events [1970]) by Jaegwon Kim - Mind in a Physical World §1 p.005 | |
| A reaction: Indeed, I find the enthusiasm for property dualism etc. quite baffling, given that we are merely told that mind is 'an anomaly'. I take it to be old fashioned dualism in trendy clothes. |
| 5497 | Mind is outside science, because it is humanistic and partly normative [Davidson, by Lycan] |
| Full Idea: For Davidson, mental types are individuated by considerations that are nonscientific, distinctly humanistic, and part normative, so will not coincide with any types that are designated in scientific terms. | |
| From: report of Donald Davidson (Mental Events [1970]) by William Lycan - Introduction - Ontology p.8 | |
| A reaction: I just don't believe this, mainly because I don't accept that there is a category called 'nonscientific'. All we are saying is that a brain is a hugely complicated object, and we don't properly understand its operations, though we relate to it very well. |
| 4081 | Anomalous monism says causes are events, so the mental and physical are identical, without identical properties [Davidson, by Crane] |
| Full Idea: Davidson's anomalous monism says that events are causes, so we can identify mental and physical events without having to identify their properties. | |
| From: report of Donald Davidson (Mental Events [1970]) by Tim Crane - Elements of Mind 2.18 | |
| A reaction: As Fodor insists, a thing like a mountain has properties at different levels of description. We can have 'property dualism' and full-blown reductive identity. |
| 2321 | If rule-following and reason are 'anomalies', does that make reductionism impossible? [Davidson, by Kim] |
| Full Idea: Davidson takes mental anomalism (that the mind exhibits normativity and rationality), and in particular his claim that there are no laws connecting mental and physical properties, to undermine mind-body reductionism. | |
| From: report of Donald Davidson (Mental Events [1970]) by Jaegwon Kim - Mind in a Physical World §4 p.092 | |
| A reaction: A nice summary of the core idea of property dualism. Personally I expect the whole lot to be reducible, and to follow laws, but the sheer complexity of the brain permanently bars us from actually doing the reduction. |
| 3404 | Davidson claims that mental must be physical, to make mental causation possible [Davidson, by Kim] |
| Full Idea: Davidson's thesis is that if mental events of a particular kind cause physical events of a particular kind, and the two kinds are connected by a law, then they must both be physical kinds. | |
| From: report of Donald Davidson (Mental Events [1970]) by Jaegwon Kim - Philosophy of Mind p.137 | |
| A reaction: Davidson would pretty obviously be right. The whole problem here is the idea of a 'law'. You can only have strict law for simple entities, like particles and natural kinds. The brain is a mess, like weather or explosions. |
| 3405 | If mental causation is lawless, it is only possible if mental events have physical properties [Davidson, by Kim] |
| Full Idea: Since no laws exist connecting mental and physical properties, purely physical laws must do the causal work, which means mental events enter into causal relations only because they possess physical properties that figure in laws. | |
| From: report of Donald Davidson (Mental Events [1970]) by Jaegwon Kim - Philosophy of Mind p.138 | |
| A reaction: Surely no such laws exist 'yet'? I can see no plausible argument that psycho-physical laws are impossible. However, the conclusion of this remark seems right. Interaction requires some sort of equality. |
| 16041 | Supervenience of the mental means physical changes mental, and mental changes physical [Davidson] |
| Full Idea: The supervenience [of mental characteristics on the physical] might be taken to mean that there cannot be two events alike in all physical respects but differing in some mental respect, or an object cannot differ mentally without altering physically. | |
| From: Donald Davidson (Mental Events [1970], I) | |
| A reaction: This is the first occasion on which Davidson introduced his notion of supervenience. Supervenience is often taken to be one-way. The first implies physical causing mental; his second implies that mental causes physical. |
| 6620 | Davidson sees identity as between events, not states, since they are related in causation [Davidson, by Lowe] |
| Full Idea: Davidson's version of the identity theory is couched in terms of events rather than states, because he regards causation as a relation between events. | |
| From: report of Donald Davidson (Mental Events [1970]) by E.J. Lowe - Introduction to the Philosophy of Mind Ch.2 n12 | |
| A reaction: I think it may be more to the point that the mind is a dynamic thing, and so it consists of events rather than states, and hence we want to know what those events are made up from. I think my chair is causing me to rest above the floor… |
| 3429 | Multiple realisability was worse news for physicalism than anomalous monism was [Davidson, by Kim] |
| Full Idea: Davidson's argument about psychophysical anomalism has not been embraced by everyone; multiple realisability of mental properties has had a much greater impact in undermining reductionism (and hence type physicalism). | |
| From: report of Donald Davidson (Mental Events [1970]) by Jaegwon Kim - Philosophy of Mind p.218 | |
| A reaction: My view is that functional states are multiply realisable, but phenomenal states aren't. Fear functions in frogs much as it does in us, but being a frightened frog is nothing like being a frightened human. Their brains are different! |
| 3524 | Causation is either between events, or between descriptions of events [Davidson, by Maslin] |
| Full Idea: According to Davidson analyses of causality proceed at two different levels: at the lower level it holds between events regardless of how they are described; higher level explanations hold between descriptions of events, which pick out properties. | |
| From: report of Donald Davidson (Mental Events [1970]) by Keith T. Maslin - Introduction to the Philosophy of Mind 7.4 |
| 3526 | Whether an event is a causal explanation depends on how it is described [Davidson, by Maslin] |
| Full Idea: Davidson says causal explanations hold between descriptions of events and not between the events themselves, so the possibility of events as explanations depends on how they are described (e.g. a wind collapsing a bridge). | |
| From: report of Donald Davidson (Mental Events [1970]) by Keith T. Maslin - Introduction to the Philosophy of Mind 7.4 |