95 ideas
| 7490 | Because of Darwin, wisdom as a definite attainable state has faded [Watson] |
| Full Idea: As well as killing the need for God, Darwin's legacy transformed the idea of wisdom, as some definite attainable state, however far off. | |
| From: Peter Watson (Ideas [2005], Ch.31) | |
| A reaction: Where does this leave philosophy, if it is still (as I like to think) the love of wisdom? The best we can hope for is wisdom as a special sort of journey - touring, rather than arriving. |
| 7461 | The three key ideas are the soul, Europe, and the experiment [Watson] |
| Full Idea: The three key ideas that I have settled on in the history of ideas are: the soul, Europe, and the experiment. | |
| From: Peter Watson (Ideas [2005], Intro) | |
| A reaction: The soul is a nice choice (rather than God). 'Europe' seems rather vast and indeterminate to count as a key idea. |
| 7464 | The big idea: imitation, the soul, experiments, God, heliocentric universe, evolution? [Watson] |
| Full Idea: Candidates for the most important idea in human history are: mimetic thinking (imitation), the soul, the experiment, the One True God, the heliocentric universe, and evolution. | |
| From: Peter Watson (Ideas [2005], Ch.03) | |
| A reaction: From this list I would choose the heliocentric universe, because it so dramatically downgraded the importance of our species (effectively we went from everything to nothing). We still haven't recovered from the shock. |
| 15357 | Philosophy is the most general intellectual discipline [Horsten] |
| Full Idea: Philosophy is the most general intellectual discipline. | |
| From: Leon Horsten (The Tarskian Turn [2011], 05.1) | |
| A reaction: Very simple, but exactly how I see the subject. It is continuous with the sciences, and tries to give an account of nature, but operating at an extreme level of generality. It must respect the findings of science, but offer bold interpretations. |
| 15352 | A definition should allow the defined term to be eliminated [Horsten] |
| Full Idea: A definition allows a defined term to be eliminated in every context in which it appears. | |
| From: Leon Horsten (The Tarskian Turn [2011], 04.2) | |
| A reaction: To do that, a definition had better be incredibly comprehensive, so that no nice nuance of the original term is thrown out. |
| 10882 | Predicative definitions only refer to entities outside the defined collection [Horsten] |
| Full Idea: Definitions are called 'predicative', and are considered sound, if they only refer to entities which exist independently from the defined collection. | |
| From: Leon Horsten (Philosophy of Mathematics [2007], §2.4) |
| 7465 | Babylonian thinking used analogy, rather than deduction or induction [Watson] |
| Full Idea: In Babylon thought seems to have worked mainly by analogy, rather than by the deductive or inductive processes we use in the modern world. | |
| From: Peter Watson (Ideas [2005], Ch.04) | |
| A reaction: Analogy seems to be closely related to induction, if it is comparing instances of something. Given their developments in maths and astronomy, they can't have been complete strangers to the 'modern' way of thought. |
| 5515 | Imaginary cases are good for revealing our beliefs, rather than the truth [Parfit] |
| Full Idea: I believe it is worth considering imaginary cases (such as Teletransportation), as we can use them to discover, not what the truth is, but what we believe. | |
| From: Derek Parfit (The Unimportance of Identity [1995], p.293) | |
| A reaction: The trouble is that we might say that IF I were suddenly turned into a pig, then I would come to believe in dualism, but that will not and cannot happen, because dualism is false. It seems essential to accept the natural possibility of the case. |
| 15324 | Semantic theories of truth seek models; axiomatic (syntactic) theories seek logical principles [Horsten] |
| Full Idea: There are semantical theories of truth, concerned with models for languages containing the truth predicate, and axiomatic (or syntactic) theories, interested in basic logical principles governing the concept of truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.1) | |
| A reaction: This is the map of contemporary debates, which seem now to have given up talking about 'correspondence', 'coherence' etc. |
| 15323 | Truth is a property, because the truth predicate has an extension [Horsten] |
| Full Idea: I take truth to be a property because the truth predicate has an extension - the collection of all true sentences - and this collection does not (unlike the 'extension' of 'exists') consist of everything, or even of all sentences. | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.1) | |
| A reaction: He concedes that it may be an 'uninteresting' property. My problem is always that I am unconvinced that truth is tied to sentences. I can make perfect sense of animal thoughts being right or wrong. Extension of mental propositions? |
| 15374 | Truth has no 'nature', but we should try to describe its behaviour in inferences [Horsten] |
| Full Idea: We should not aim at describing the nature of truth because there is no such thing. Rather, we should aim at describing the inferential behaviour of truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 10.2.3) |
| 15348 | Propositions have sentence-like structures, so it matters little which bears the truth [Horsten] |
| Full Idea: It makes little difference, at least in extensional contexts, whether the truth bearers are propositions or sentences (or assertions). Even if the bearers are propositions rather than sentences, propositions are structured rather like sentences. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.4) | |
| A reaction: The 'extensional' context means you are only talking about the things that are referred to, and not about the way this is expressed. I prefer propositions, but this is an interesting point. |
| 15333 | Modern correspondence is said to be with the facts, not with true propositions [Horsten] |
| Full Idea: Modern correspondence theorists no longer take things to correspond to true propositions; they consider facts to be the truthmakers of propositions. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.1) | |
| A reaction: If we then define facts as the way certain things are, independently from our thinking about it, at least we seem to be avoiding circularity. Not much point in correspondence accounts if you are not a robust realist (like me). [14,000th idea, 23/4/12!] |
| 15337 | The correspondence 'theory' is too vague - about both 'correspondence' and 'facts' [Horsten] |
| Full Idea: The principle difficulty of the correspondence theory of truth is its vagueness. It is too vague to be called a theory until more information is given about what is meant by the terms 'correspondence' and 'fact'. Facts can involve a heavy ontology. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.1) | |
| A reaction: I see nothing here to make me give up my commitment to the correspondence view of truth, though it sounds as if I will have to give up the word 'theory' in that context. Truth is so obviously about thought fitting reality that there is nothing to discuss. |
| 15334 | The coherence theory allows multiple coherent wholes, which could contradict one another [Horsten] |
| Full Idea: The coherence theory seems too liberal. It seems there can be more than one systematic whole which, while being internally coherent, contradict each other, and thus cannot all be true. Coherence is a necessary but not sufficient condition for truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.1) | |
| A reaction: This is a modern post-Tarski axiomatic truth theorist making very short work indeed of the coherence theory of truth. I take Horsten to be correct. |
| 15336 | The pragmatic theory of truth is relative; useful for group A can be useless for group B [Horsten] |
| Full Idea: The pragmatic theory is unsatisfactory because usefulness is a relative notion. One theory can be useful to group A while being thoroughly impractical for group B. This would make the theory both truth and false. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.1) | |
| A reaction: This objection, along with the obvious fact that certain falsehoods can be very useful, would seem to rule pragmatism out as a theory of truth. It is, in fact, an abandonment of truth. |
| 15354 | Tarski's hierarchy lacks uniform truth, and depends on contingent factors [Horsten] |
| Full Idea: According to the Tarskian hierarchical conception, truth is not a uniform notion. ...Also Kripke has emphasised that the level of a token of the truth predicate can depend on contingent factors, such as what else has been said by a speaker. | |
| From: Leon Horsten (The Tarskian Turn [2011], 04.5) |
| 15340 | Tarski Bi-conditional: if you'll assert φ you'll assert φ-is-true - and also vice versa [Horsten] |
| Full Idea: The axiom schema 'Sentence "phi;" is true iff φ' is the (unrestricted) Tarski-Biconditional, and is motivated by the thought that if you are willing to assume or outright assert that φ, you will assert that φ is true - and also vice versa. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.2) | |
| A reaction: Very helpful! Most people are just bewildered by the Tarski bi-conditional ('"Snow is white"...), but this formulation nicely shows its minimal character while showing that it really does say something. It says what truths and truth-claims commit you to. |
| 15345 | Semantic theories have a regress problem in describing truth in the languages for the models [Horsten] |
| Full Idea: Semantic theories give a class of models with a truth predicate, ...but Tarski taught us that this needs a more encompassing framework than its language...so how is the semantics of the framework expressed? The model route has a regress. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.3) | |
| A reaction: [compressed] So this regress problem, of endless theories of truth going up the hierarchy, is Horsten's main reason for opting for axiomatic theories, which he then tries to strengthen, so that they are not quite so deflated. |
| 15373 | Axiomatic approaches avoid limiting definitions to avoid the truth predicate, and limited sizes of models [Horsten] |
| Full Idea: An adequate definition of truth can only be given for the fragment of our language that does not contain the truth predicate. A model can never encompass the whole of the domain of discourse of our language. The axiomatic approach avoids these problems. | |
| From: Leon Horsten (The Tarskian Turn [2011], 10.1) |
| 15346 | Axiomatic approaches to truth avoid the regress problem of semantic theories [Horsten] |
| Full Idea: The axiomatic approach to truth does not suffer from the regress problem. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.3) | |
| A reaction: See Idea 15345 for the regress problem. The difficulty then seems to be that axiomatic approaches lack expressive power, so the hunt is on for a set of axioms which will do a decent job. Fun work, if you can cope with it. |
| 15371 | An axiomatic theory needs to be of maximal strength, while being natural and sound [Horsten] |
| Full Idea: The challenge is to find the arithmetically strongest axiomatical truth theory that is both natural and truth-theoretically sound. | |
| From: Leon Horsten (The Tarskian Turn [2011], 07.7) |
| 15332 | 'Reflexive' truth theories allow iterations (it is T that it is T that p) [Horsten] |
| Full Idea: A theory of truth is 'reflexive' if it allows us to prove truth-iterations ("It is true that it is true that so-and-so"). | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.4) |
| 15361 | A good theory of truth must be compositional (as well as deriving biconditionals) [Horsten] |
| Full Idea: Deriving many Tarski-biconditionals is not a sufficient condition for being a good theory of truth. A good theory of truth must in addition do justice to the compositional nature of truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 06.1) |
| 15350 | The Naïve Theory takes the bi-conditionals as axioms, but it is inconsistent, and allows the Liar [Horsten] |
| Full Idea: The Naïve Theory of Truth collects all the Tarski bi-conditionals of a language and takes them as axioms. But no consistent theory extending Peano arithmetic can prove all of them. It is inconsistent, and even formalises the liar paradox. | |
| From: Leon Horsten (The Tarskian Turn [2011], 03.5.2) | |
| A reaction: [compressed] This looks to me like the account of truth that Davidson was working with, since he just seemed to be compiling bi-conditionals for tricky cases. (Wrong! He championed the Compositional Theory, Horsten p.71) |
| 15351 | Axiomatic theories take truth as primitive, and propose some laws of truth as axioms [Horsten] |
| Full Idea: In the axiomatic approach we take the truth predicate to express an irreducible, primitive notion. The meaning of the truth predicate is partially explicated by proposing certain laws of truth as basic principles, as axioms. | |
| From: Leon Horsten (The Tarskian Turn [2011], 04.2) | |
| A reaction: Judging by Horsten's book, this is a rather fruitful line of enquiry, but it still seems like a bit of a defeat to take truth as 'primitive'. Presumably you could add some vague notion of correspondence as the background picture. |
| 15367 | By adding truth to Peano Arithmetic we increase its power, so truth has mathematical content! [Horsten] |
| Full Idea: It is surprising that just by adding to Peano Arithmetic principles concerning the notion of truth, we increase the mathematical strength of PA. So, contrary to expectations, the 'philosophical' notion of truth has real mathematical content. | |
| From: Leon Horsten (The Tarskian Turn [2011], 06.4) | |
| A reaction: Horsten invites us to be really boggled by this. All of this is in the Compositional Theory TC. It enables a proof of the consistency of arithmetic (but still won't escape Gödel's Second). |
| 15330 | Friedman-Sheard theory keeps classical logic and aims for maximum strength [Horsten] |
| Full Idea: The Friedman-Sheard theory of truth holds onto classical logic and tries to construct a theory that is as strong as possible. | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.4) |
| 15331 | Kripke-Feferman has truth gaps, instead of classical logic, and aims for maximum strength [Horsten] |
| Full Idea: If we abandon classical logic in favour of truth-value gaps and try to strengthen the theory, this leads to the Kripke-Feferman theory of truth, and variants of it. | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.4) |
| 15325 | Inferential deflationism says truth has no essence because no unrestricted logic governs the concept [Horsten] |
| Full Idea: According to 'inferential deflationism', truth is a concept without a nature or an essence. This is betrayed by the fact that there are no unrestricted logical laws that govern the concept of truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.1) |
| 15344 | Deflationism skips definitions and models, and offers just accounts of basic laws of truth [Horsten] |
| Full Idea: Contemporary deflationism about truth does not attempt to define truth, and does not rely on models containing the truth predicate. Instead they are interpretations of axiomatic theories of truth, containing only basic laws of truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.3) |
| 15356 | Deflationism concerns the nature and role of truth, but not its laws [Horsten] |
| Full Idea: Deflationism is not a theory of the laws of truth. It is a view on the nature and role of the concept of truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 05 Intro) |
| 15368 | This deflationary account says truth has a role in generality, and in inference [Horsten] |
| Full Idea: On the conception of deflationism developed in this book, the prime positive role of the truth predicate is to serve as a device for expressing generalities, and an inferential tool. | |
| From: Leon Horsten (The Tarskian Turn [2011], 07.5) |
| 15358 | Deflationism says truth isn't a topic on its own - it just concerns what is true [Horsten] |
| Full Idea: Deflationism says the theory of truth does not have a substantial domain of its own. The domain of the theory of truth consists of the bearers of truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 05.1) | |
| A reaction: The immediate thought is that truth also concerns falsehoods, which would be inexplicable without it. If physics just concerns the physical, does that mean that physics lacks its own 'domain'? Generalising about the truths is a topic. |
| 15359 | Deflation: instead of asserting a sentence, we can treat it as an object with the truth-property [Horsten] |
| Full Idea: The Deflationary view just says that instead of asserting a sentence, we can turn the sentence into an object and assert that this object has the property of truth. | |
| From: Leon Horsten (The Tarskian Turn [2011], 05.2.2) | |
| A reaction: That seems to leave a big question hanging, which concerns the nature of the property that is being attributed to this object. Quine 1970:10-13 says it is just a 'device'. Surely you can rest content with that as an account of truth? |
| 15329 | Nonclassical may accept T/F but deny applicability, or it may deny just T or F as well [Horsten] |
| Full Idea: Some nonclassical logic stays close to classical, assuming two mutually exclusive truth values T and F, but some sentences fail to have one. Others have further truth values such as 'half truth', or dialethists allow some T and F at the same time. | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.2) | |
| A reaction: I take that to say that the first lot accept bivalence but reject excluded middle (allowing 'truth value gaps'), while the second lot reject both. Bivalence gives the values available, and excluded middle says what has them. |
| 15326 | Doubt is thrown on classical logic by the way it so easily produces the liar paradox [Horsten] |
| Full Idea: Aside from logic, so little is needed to generate the liar paradox that one wonders whether the laws of classical logic are unrestrictedly valid after all. (Many theories of truth have therefore been formulated in nonclassical logic.) | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.2) | |
| A reaction: Kripke uses Strong Kleene logic for his theory. The implication is that debates discussed by Horsten actually have the status of classical logic at stake, as well as the nature of truth. |
| 15341 | Deduction Theorem: ψ only derivable from φ iff φ→ψ are axioms [Horsten] |
| Full Idea: The Deduction Theorem says ψ is derivable in classical predicate logic from ψ iff the sentence φ→ψ is a theorem of classical logic. Hence inferring φ to ψ is truth-preserving iff the axiom scheme φ→ψ is provable. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.2) | |
| A reaction: Horsten offers this to show that the Tarski bi-conditionals can themselves be justified, and not just the rule of inference involved. Apparently you can only derive something if you first announce that you have the ability to derive it. Odd. |
| 15328 | A theory is 'non-conservative' if it facilitates new mathematical proofs [Horsten] |
| Full Idea: A theory is 'non-conservative' if it allows us to prove mathematical facts that go beyond what the background mathematical theory can prove on its own. | |
| From: Leon Horsten (The Tarskian Turn [2011], 01.4) | |
| A reaction: This is an instance of the relationship with mathematics being used as the test case for explorations of logic. It is a standard research method, because it is so precise, but should not be mistaken for the last word about a theory. |
| 15349 | It is easier to imagine truth-value gaps (for the Liar, say) than for truth-value gluts (both T and F) [Horsten] |
| Full Idea: It is easier to imagine what it is like for a sentence to lack a truth value than what it is like for a sentence to be both truth and false. So I am grudgingly willing to entertain the possibility that certain sentences (like the Liar) lack a truth value. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.5) | |
| A reaction: Fans of truth value gluts are dialethists like Graham Priest. I'm with Horsten on this one. But in what way can a sentence be meaningful if it lacks a truth-value? He mentions unfulfilled presuppositions and indicative conditionals as gappy. |
| 15366 | Satisfaction is a primitive notion, and very liable to semantical paradoxes [Horsten] |
| Full Idea: Satisfaction is a more primitive notion than truth, and it is even more susceptible to semantical paradoxes than the truth predicate. | |
| From: Leon Horsten (The Tarskian Turn [2011], 06.3) | |
| A reaction: The Liar is the best known paradox here. Tarski bases his account of truth on this primitive notion, so Horsten is pointing out the difficulties. |
| 10884 | A theory is 'categorical' if it has just one model up to isomorphism [Horsten] |
| Full Idea: If a theory has, up to isomorphism, exactly one model, then it is said to be 'categorical'. | |
| From: Leon Horsten (Philosophy of Mathematics [2007], §5.2) |
| 15353 | The first incompleteness theorem means that consistency does not entail soundness [Horsten] |
| Full Idea: It is a lesson of the first incompleteness theorem that consistency does not entail soundness. If we add the negation of the gödel sentence for PA as an extra axiom to PA, the result is consistent. This negation is false, so the theory is unsound. | |
| From: Leon Horsten (The Tarskian Turn [2011], 04.3) |
| 15355 | Strengthened Liar: 'this sentence is not true in any context' - in no context can this be evaluated [Horsten] |
| Full Idea: The Strengthened Liar sentence says 'this sentence is not true in any context'. It is not hard to figure out that there is no context in which the sentence can be coherently evaluated. | |
| From: Leon Horsten (The Tarskian Turn [2011], 04.6) |
| 15364 | English expressions are denumerably infinite, but reals are nondenumerable, so many are unnameable [Horsten] |
| Full Idea: The number of English expressions is denumerably infinite. But Cantor's theorem can be used to show that there are nondenumerably many real numbers. So not every real number has a (simple or complex name in English). | |
| From: Leon Horsten (The Tarskian Turn [2011], 06.3) | |
| A reaction: This really bothers me. Are we supposed to be committed to the existence of entities which are beyond our powers of naming? How precise must naming be? If I say 'pick a random real number', might that potentially name all of them? |
| 7466 | Mesopotamian numbers applied to specific things, and then became abstract [Watson] |
| Full Idea: To begin with, in Mesopotamia, counting systems applied to specific commodities (so the symbol for 'three sheep' applied only to sheep, and 'three cows' applied only to cows), but later words for abstract qualities emerged. | |
| From: Peter Watson (Ideas [2005], Ch.04) | |
| A reaction: It seems from this that we actually have a record of the discovery of true numbers. Delightful. I think the best way to describe what happened is that they began to spot patterns. |
| 10885 | Computer proofs don't provide explanations [Horsten] |
| Full Idea: Mathematicians are uncomfortable with computerised proofs because a 'good' proof should do more than convince us that a certain statement is true. It should also explain why the statement in question holds. | |
| From: Leon Horsten (Philosophy of Mathematics [2007], §5.3) |
| 10881 | The concept of 'ordinal number' is set-theoretic, not arithmetical [Horsten] |
| Full Idea: The notion of an ordinal number is a set-theoretic, and hence non-arithmetical, concept. | |
| From: Leon Horsten (Philosophy of Mathematics [2007], §2.3) |
| 15360 | ZFC showed that the concept of set is mathematical, not logical, because of its existence claims [Horsten] |
| Full Idea: One of the strengths of ZFC is that it shows that the concept of set is a mathematical concept. Many originally took it to be a logical concept. But ZFC makes mind-boggling existence claims, which should not follow if it was a logical concept. | |
| From: Leon Horsten (The Tarskian Turn [2011], 05.2.3) | |
| A reaction: This suggests that set theory is not just a way of expressing mathematics (see Benacerraf 1965), but that some aspect of mathematics has been revealed by it - maybe even its essential nature. |
| 15369 | Set theory is substantial over first-order arithmetic, because it enables new proofs [Horsten] |
| Full Idea: The nonconservativeness of set theory over first-order arithmetic has done much to establish set theory as a substantial theory indeed. | |
| From: Leon Horsten (The Tarskian Turn [2011], 07.5) | |
| A reaction: Horsten goes on to point out the price paid, which is the whole new ontology which has to be added to the arithmetic. Who cares? It's all fictions anyway! |
| 15370 | Predicativism says mathematical definitions must not include the thing being defined [Horsten] |
| Full Idea: Predicativism has it that a mathematical object (such as a set of numbers) cannot be defined by quantifying over a collection that includes that same mathematical object. To do so would be a violation of the vicious circle principle. | |
| From: Leon Horsten (The Tarskian Turn [2011], 07.7) | |
| A reaction: In other words, when you define an object you are obliged to predicate something new, and not just recycle the stuff you already have. |
| 5516 | Reduction can be by identity, or constitution, or elimination [Parfit, by PG] |
| Full Idea: We can distinguish Identifying Reductionism (as in 'persons are bodies'), or Constitutive Reductionism (as in 'persons are distinct, but consist of thoughts etc.'), or Eliminative Reductionism (as in 'there are no persons, only thoughts etc.'). | |
| From: report of Derek Parfit (The Unimportance of Identity [1995], p.295) by PG - Db (ideas) | |
| A reaction: Constitutive Reductionism seems the most common one, as in 'chemistry just consists of lots of complicated physics'. He doesn't mention bridge laws, which are presumably only required in more complicated cases of constitutive reduction. |
| 15338 | We may believe in atomic facts, but surely not complex disjunctive ones? [Horsten] |
| Full Idea: While positive and perhaps even negative atomic facts may be unproblematic, it seems excessive to commit oneself to the existence of logically complex facts such as disjunctive facts. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.1) | |
| A reaction: Presumably it is hard to deny that very complex statements involving massive disjunctions can be true or false. But why does commitment to real facts have to involve a huge ontology? The ontology is just the ingredients of the fact, isn't it? |
| 15363 | In the supervaluationist account, disjunctions are not determined by their disjuncts [Horsten] |
| Full Idea: If 'Britain is large' and 'Italy is large' lack truth values, then so must 'Britain or Italy is large' - so on the supervaluationist account the truth value of a disjunction is not determined by the truth values of its disjuncts. | |
| From: Leon Horsten (The Tarskian Turn [2011], 06.2) | |
| A reaction: Compare Idea 15362 to get the full picture here. |
| 15362 | If 'Italy is large' lacks truth, so must 'Italy is not large'; but classical logic says it's large or it isn't [Horsten] |
| Full Idea: If 'Italy is a large country' lacks a truth value, then so too, presumably, does 'Italy is not a large country'. But 'Italy is or is not a large country' is true, on the supervaluationist account, because it is a truth of classical propositional logic. | |
| From: Leon Horsten (The Tarskian Turn [2011], 06.2) | |
| A reaction: See also Idea 15363. He cites Fine 1975. |
| 15372 | Some claim that indicative conditionals are believed by people, even though they are not actually held true [Horsten] |
| Full Idea: In the debate about doxastic attitudes towards indicative conditional sentences, one finds philosophers who claim that conditionals can be believed even though they have no truth value (and thus are not true). | |
| From: Leon Horsten (The Tarskian Turn [2011], 09.3) |
| 20657 | There are 23 core brain functions, with known circuit, transmitters, genes and behaviour [Watson] |
| Full Idea: In 2014 the National Institutes of Mental Health published a list of 23 core brain functions and their associated neural circuitry, neurotransmitters and genes, and the behaviour and emotions that go with them. | |
| From: Peter Watson (Convergence [2016], 16 'Physics') | |
| A reaction: They were interested in the functions behind mental health, but I am interested in the functions behind our belief systems, which might produce a different focus. Sub-functions, perhaps. |
| 3539 | Personal identity is just causally related mental states [Parfit, by Maslin] |
| Full Idea: For Parfit all personal identity really amounts to is a chain of experiences and other psychological features causally related to each other in 'direct' sorts of ways. | |
| From: report of Derek Parfit (Personal Identity [1971]) by Keith T. Maslin - Introduction to the Philosophy of Mind 10.5 | |
| A reaction: When summarised like this, it strikes me that Parfit is just false to our experience, whatever Hume may say. I suspect that Parfit (and those like him) concentrate too much on rather passive perceptual experience, and neglect the will. |
| 5514 | Psychologists are interested in identity as a type of person, but philosophers study numerical identity [Parfit] |
| Full Idea: When psychologists discuss identity, they are typically concerned with the kind of person someone is, or wants to be (as in an 'identity crisis'). But when philosophers discuss identity, it is numerical identity they mean. | |
| From: Derek Parfit (The Unimportance of Identity [1995], p.293) | |
| A reaction: I think it is important to note that the philosophical problem breaks down into two areas: whether I have numerical identity with myself over time, and whether other people have it. It may be that two different sets of criteria will emerge. |
| 1393 | One of my future selves will not necessarily be me [Parfit] |
| Full Idea: If I say 'It will not be me, but one of my future selves', I do not imply that I will be that future self. He is one of my later selves, and I am one of his earlier selves. There is no underlying person we both are. | |
| From: Derek Parfit (Personal Identity [1971], §5) | |
| A reaction: The problem here seems to be explaining why I should care about my later self, if it isn't me. If the answer is only that it will be psychologically very similar to me, then I would care more about my current identical twin than about my future self. |
| 5521 | If my brain-halves are transplanted into two bodies, I have continuity, and don't need identity [Parfit] |
| Full Idea: If the two halves of my brain are transplanted into different bodies just like mine, they cannot both be me, since that would make them the same person. ..But my relation to these two contains everything that matters, so identity is not what matters. | |
| From: Derek Parfit (The Unimportance of Identity [1995], p.314) | |
| A reaction: I challenge his concept of what 'matters'. He has a rather solipsistic view of the problem, and I take Parfit to be a rather unsociable person, since his friends and partner will be keenly interested in the identities of the new beings. |
| 5522 | Over a period of time what matters is not that 'I' persist, but that I have psychological continuity [Parfit] |
| Full Idea: We should revise our view about identity over time: what matters isn't that there will be someone alive who will be me; it is rather that there should be at least one living person who will be psychologically continuous with me as I am now. | |
| From: Derek Parfit (The Unimportance of Identity [1995], p.316) | |
| A reaction: Parfit and Locke seem to agree on this, and it is no accident that they both like 'science fiction' examples. Apparently Parfit wouldn't bat an eyelid if someone threatened to cut his corpus callosum. I rate it as a catastrophe for my current existence. |
| 1392 | If we split like amoeba, we would be two people, neither of them being us [Parfit] |
| Full Idea: In the case of the man who, like an amoeba, divides….we can suggest that he survives as two different people without implying that he is those people. | |
| From: Derek Parfit (Personal Identity [1971], §1) | |
| A reaction: Maybe an amoeba is a homogeneous substance for which splitting is insignificant, but when a person has certain parts that are totally crucial, splitting them is catastrophic, and quite different. I'm not sure that splitting a self would leave persons. |
| 5519 | It is fine to save two dying twins by merging parts of their bodies into one, and identity is irrelevant [Parfit] |
| Full Idea: If I am largely paralysed, and my twin brother is dying of brain disease, then if the operation to graft my head onto his body is offered, I should accept the operation, and it is irrelevant whether this person would be me. | |
| From: Derek Parfit (The Unimportance of Identity [1995], p.308) | |
| A reaction: Parfit notes that the brain is a particularly significant part of the process. The fact that I might cheerfully accept this offer without philosophical worries doesn't get rid of the question 'who is this person?' Who should they remain married to? |
| 5520 | If two humans are merged surgically, the new identity is a purely verbal problem [Parfit] |
| Full Idea: If there is someone with my head and my brother's body, it is a merely verbal question whether that person will be me, and that is why, even if it won't be me, that doesn't matter. ..What matters is not identity, but the facts of which identity consists. | |
| From: Derek Parfit (The Unimportance of Identity [1995], p.310) | |
| A reaction: It strikes me that from the subjective psychological point of view identity is of little interest, but from the objective external viewpoint (e.g. the forensic one) such questions are highly significant, and rightly so. |
| 1391 | Concern for our own lives isn't the source of belief in identity, it is the result of it [Parfit] |
| Full Idea: Egoism, and the fear not of near but of distant death, and the regret that so much of one's life should have gone by - these are not, I think, wholly natural or instinctive. They are strengthened by a false belief in stable identity. | |
| From: Derek Parfit (Personal Identity [1971], §6) | |
| A reaction: This raises some very nice questions, about the extent to which various aspects of self-concern are instinctive and natural, or culturally induced, and even totally misguided and false. I can worry about the distant death of my guinea pig, or my grandson. |
| 5518 | It doesn't matter whether I exist with half my components replaced (any more than an audio system) [Parfit] |
| Full Idea: It is quite uninteresting whether, with half its components replaced, I have the same audio system, and also whether I exist if half of my body were simultaneously replaced. | |
| From: Derek Parfit (The Unimportance of Identity [1995], p.302) | |
| A reaction: It is impossible to deny this, if the part replaced is not the brain. My doubt about Parfit's thesis is that while I may not care whether some modified thing is still me, my lawyers and the police might be very concerned. |
| 20656 | Traditional ideas of the mind were weakened in the 1950s by mind-influencing drugs [Watson] |
| Full Idea: One development in particular in the 1950s helped to discredit the traditional concept of the mind. This was medical drugs that influenced the workings of the brain. | |
| From: Peter Watson (Convergence [2016], 16 'Intro') | |
| A reaction: This explains Ryle's 1949 book, and the Australian physicalists emerging in the late 1950s. Philosophers don't grasp how their subject is responsive to other areas of human knowledge. Of course, opium had always done this. |
| 15347 | A theory of syntax can be based on Peano arithmetic, thanks to the translation by Gödel coding [Horsten] |
| Full Idea: A notion of formal provability can be articulated in Peano arithmetic. ..This is surprisingly 'linguistic' rather than mathematical, but the key is in the Gödel coding. ..Hence we use Peano arithmetic as a theory of syntax. | |
| From: Leon Horsten (The Tarskian Turn [2011], 02.4) | |
| A reaction: This is the explanation of why issues in formal semantics end up being studied in systems based on formal arithmetic. And I had thought it was just because they were geeks who dream in numbers, and can't speak language properly... |
| 20655 | Humans have been hunter-gatherers for 99.5% of their existence [Watson] |
| Full Idea: Anthropology shows that the hunter-gathering lifestyle has occupied 99.5 per cent of the time humans have been on earth. | |
| From: Peter Watson (Convergence [2016], 13 'Emergence') | |
| A reaction: If you are trying to understand humanity, you ignore this fact at your peril. Even agriculture is only a tiny part of our history, and that only disappeared as a major human activity (in many nations) in the last hundred years. |
| 9762 | We should focus less on subjects of experience, and more on the experiences themselves [Parfit] |
| Full Idea: It becomes more plausible, when thinking morally, to focus less upon the person, the subject of experiences, and instead to focus more upon the experiences themselves. | |
| From: Derek Parfit (Reasons and Persons [1984], §116) | |
| A reaction: This pinpoints how Parfit moves from a view of persons in terms of continuity of consciousness to a utilitarian morality. It brings out nicely what is wrong with utilitarianism - the reductio of a great ball of nice experiences, with no one having them. |
| 7477 | Modern democracy is actually elective oligarchy [Watson] |
| Full Idea: What we regard as democracy in the twenty-first century is actually elective oligarchy. | |
| From: Peter Watson (Ideas [2005], Ch.06) | |
| A reaction: Even dictatorships want to be called 'democracies'. The modern system is a bit of a concession to Plato, and he would probably have preferred it to his system, because at least the rulers tend to be more educated than the direct assembly. |
| 7478 | Greek philosophers invented the concept of 'nature' as their special subject [Watson] |
| Full Idea: Greek philosophers may have invented the concept of 'nature' to underline their superiority over poets and religious leaders. | |
| From: Peter Watson (Ideas [2005], Ch.06) | |
| A reaction: Brilliant. They certainly wrote a lot of books entitled 'Peri Physis' (Concerning Nature), and it was the target of their expertise. A highly significant development, along with their rational methods. Presumably Socrates extends nature to include ethics. |
| 20650 | The Uncertainty Principle implies that cause and effect can't be measured [Watson] |
| Full Idea: The Uncertainty Principle implied that in the subatomic world cause and effect could never be measured. | |
| From: Peter Watson (Convergence [2016], 05 'Against') | |
| A reaction: The fact that it can't be measured does not, presumably, entail that it doesn't exist. Physicists seem to ignore causation, rather than denying it. Can causation be real if it only exists at the macro-level, as an emergent phenomenon? |
| 20649 | The interference of light through two slits confirmed that it is waves [Watson] |
| Full Idea: Thomas Young in 1803 confirmed the idea of Huyghens that light is waves, showing how light passing through two slits produces an interference pattern that resembles water waves sluicing through two slits. | |
| From: Peter Watson (Convergence [2016], 04 'Conception') | |
| A reaction: The great puzzle emerges when it also turns out to be quantised particles. |
| 20661 | Electrons rotate in hyrogen atoms 10^13 times per second [Watson] |
| Full Idea: In the hydrogen atom the electron rotates some 10,000 billion times per second. | |
| From: Peter Watson (Convergence [2016], 18 'Evolutionary') | |
| A reaction: That's an awful lot. Is it at the speed of light? |
| 20647 | Quantum theory explains why nature is made up of units, such as elements [Watson] |
| Full Idea: Planck's quantum idea explained so much, including the observation that the chemical world is made up of discrete units - the elements. Discrete elements implied fundamental units of matter that were themselves discrete (as Dalton had said). | |
| From: Peter Watson (Convergence [2016], 4 'Intro') | |
| A reaction: The atomic theory was only finally confirmed by Einstein in 1905. This idea implies that the very lowest level of all must have distinct building blocks, but so far we have got down to 'fields', which seem to be a sort of 'foam'. |
| 20654 | Only four particles are needed for matter: up and down quark, electron, electron-neutrino [Watson] |
| Full Idea: We need twelve particles in the master equation of the standard model, but it is necessary to have only four to build a universe (up and down quarks, the electron and the electron neutrino (or lepton). The existence of the others is 'a bit of a mystery'. | |
| From: Peter Watson (Convergence [2016], 11 'First Three') |
| 20651 | The shape of molecules is important, as well as the atoms and their bonds [Watson] |
| Full Idea: Pauling showed that the architecture - the shape of molecules was relevant (as well as the bonds). This meant that molecules were just as important as atoms in the understanding of matter. Molecules were not just the sum of their parts. | |
| From: Peter Watson (Convergence [2016], 05 'Three') | |
| A reaction: If Aristotle struggled to understand matter, then so should modern philosophers. This involves thermodynamics and chemistry, as well as quantum theory. |
| 20652 | In 1828 the animal substance urea was manufactured from inorganic ingredients [Watson] |
| Full Idea: In 1828 Wöhler, in an iconic experiment, had manufactured an organic substance, urea, hitherto the product solely of animals, out of inorganic materials, and without any interventions of vital force. | |
| From: Peter Watson (Convergence [2016], 06 'Inorganic') | |
| A reaction: For reductionists like me, the gradual explanation of life in inorganic terms is the great role model of explanation. I take it for granted that the human mind will go the same way, despite partisan resistance from a lot of philosophers. |
| 20658 | Information is physical, and living can be seen as replicating and preserving information [Watson] |
| Full Idea: In passing information, physical changes take place, and information is thus physical. On this account, the act of living can be seen as replicating and preserving the information that a living body is comprised of. | |
| From: Peter Watson (Convergence [2016], 17 'Dreams') | |
| A reaction: [He emphasises 'the act' of living, rather than a life] |
| 7462 | DNA mutation suggests humans and chimpanzees diverged 6.6 million years ago [Watson] |
| Full Idea: The basic mutation rate in DNA is 0.71 percent per million years. Working back from the present difference between human and chimpanzee DNA, we arrive at 6.6 million years ago for their divergence. | |
| From: Peter Watson (Ideas [2005], Ch.01) | |
| A reaction: This database is committed to evolution (a reminder that even databases have commitments), and so facts of this kind are included, even though they are not strictly philosophical. All complaints should be inwardly digested and forgotten. |
| 7470 | During the rise of civilizations, the main gods changed from female to male [Watson] |
| Full Idea: Around the time of the rise of the first great civilizations, the main gods changed sex, as the Great Goddess, or a raft of smaller goddesses, were demoted and male gods took their place. | |
| From: Peter Watson (Ideas [2005], Ch.05) | |
| A reaction: Why? War, perhaps? |
| 7474 | Hinduism has no founder, or prophet, or creed, or ecclesiastical structure [Watson] |
| Full Idea: Traditional Hinduism has been described as more a way of living than a way of thought; it has no founder, no prophet, no creed and no ecclesiastical structure. | |
| From: Peter Watson (Ideas [2005], Ch.05) | |
| A reaction: This contrast strikingly with all later religions, which felt they had to follow the Jews in becoming a 'religion of the book', with a sacred text, and hence a special status for the author(s) of that text. |
| 7480 | Monotheism was a uniquely Israelite creation within the Middle East [Watson] |
| Full Idea: No one questions the fact that monotheism was a uniquely Israelite creation within the Middle East. | |
| From: Peter Watson (Ideas [2005], Ch.07) | |
| A reaction: I take the Middle East to exclude Greece, where they were developing similar ideas. Who knows? |
| 7479 | Modern Judaism became stabilised in 200 CE [Watson] |
| Full Idea: The Judaism we know today didn't become stabilized until roughly 200 CE. | |
| From: Peter Watson (Ideas [2005], Ch.07) | |
| A reaction: By that stage it would have been subject to the influences of Christianity, ancient Greek philosophy, and neo-Platonism. |
| 7481 | The Israelites may have asserted the uniqueness of Yahweh to justify land claims [Watson] |
| Full Idea: Archaeology offers datable figures that seem to support the idea that the Israelites of the 'second exile' period converted Yahweh into a special, single God to justify their claims to the land. | |
| From: Peter Watson (Ideas [2005], Ch.07) | |
| A reaction: The implications for middle eastern politics of this wicked observation are beyond the remit of a philosophy database. |
| 7471 | The Gathas (hymns) of Zoroastrianism date from about 1000 BCE [Watson] |
| Full Idea: The Gathas, the liturgical hymns that make up the 'Avesta', the Zoroastrian canon, are very similar in language to the oldest Sanskrit of Hinduism, so they are not much younger than 1200 BCE. | |
| From: Peter Watson (Ideas [2005], Ch.05) | |
| A reaction: This implies a big expansion of religion before the well-known expansion of the sixth century BCE. |
| 7473 | Zoroaster conceived the afterlife, judgement, heaven and hell, and the devil [Watson] |
| Full Idea: Life after death, resurrection, judgement, heaven and paradise, were all Zoroastrian firsts, as were hell and the devil. | |
| From: Peter Watson (Ideas [2005], Ch.05) | |
| A reaction: He appears to be the first 'prophet'. |
| 7484 | Jesus never intended to start a new religion [Watson] |
| Full Idea: Jesus never intended to start a new religion. | |
| From: Peter Watson (Ideas [2005], Ch.08) | |
| A reaction: An intriguing fact, which makes you wonder whether any of the prophets ever had such an intention. |
| 7483 | Paul's early writings mention few striking episodes from Jesus' life [Watson] |
| Full Idea: Paul's writings - letters mainly - predate the gospels and yet make no mention of many of the more striking episodes that make up Jesus' life. | |
| From: Peter Watson (Ideas [2005], Ch.07) | |
| A reaction: This is not proof of anything, but it seems very significant if we are trying to get at the facts about Jesus. |
| 7475 | Confucius revered the spiritual world, but not the supernatural, or a personal god, or the afterlife [Watson] |
| Full Idea: Confucius was deeply religious in a traditional sense, showing reverence towards heaven and an omnipresent spiritual world, but he was cool towards the supernatural, and does not seem to have believed in either a personal god or an afterlife. | |
| From: Peter Watson (Ideas [2005], Ch.05) | |
| A reaction: The implication is that the spiritual world was very remote from us, and beyond communication. Sounds like deism. |
| 7476 | Taoism aims at freedom from the world, the body, the mind, and nature [Watson] |
| Full Idea: Underlying Taoism is a search for freedom - from the world, from the body, from the mind, from nature. | |
| From: Peter Watson (Ideas [2005], Ch.05) | |
| A reaction: Of all the world's religions, I think Taoism is the most ridiculouly misconceived. |
| 7463 | The three basic ingredients of religion are: the soul, seers or priests, and ritual [Watson] |
| Full Idea: Anthropologist distinguish three requirements for religion: a non-physical soul which can survive death; individuals who can receive supernatural inspiration; and rituals which can cause changes in the present world. | |
| From: Peter Watson (Ideas [2005], Ch.01) | |
| A reaction: The latter two, of course, also imply belief in supernatural powers. |
| 7468 | In ancient Athens the souls of the dead are received by the 'upper air' [Watson] |
| Full Idea: An official Athenian war monument of 432 BCE says the souls of the dead will be received by the aither (the 'upper air'), though their bodies remain on earth. | |
| From: Peter Watson (Ideas [2005], Ch.05) | |
| A reaction: Intriguing. Did they think anything happened when they got there? There are also ideas about Hades, and the Isles of the Blessed floating around. |