73 ideas
| 2463 | A standard naturalist view is realist, externalist, and computationalist, and believes in rationality [Fodor] |
| Full Idea: There seems to be an emerging naturalist consensus that is Realist in ontology and epistemology, externalist in semantics, and computationalist in cognitive psychology, which nicely allows us to retain our understanding of ourselves as rational creatures. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) |
| 9955 | Contextual definitions replace a complete sentence containing the expression [George/Velleman] |
| Full Idea: A contextual definition shows how to analyse an expression in situ, by replacing a complete sentence (of a particular form) in which the expression occurs by another in which it does not. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.2) | |
| A reaction: This is a controversial procedure, which (according to Dummett) Frege originally accepted, and later rejected. It might not be the perfect definition that replacing just the expression would give you, but it is a promising step. |
| 10031 | Impredicative definitions quantify over the thing being defined [George/Velleman] |
| Full Idea: When a definition contains a quantifier whose range includes the very entity being defined, the definition is said to be 'impredicative'. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.2) | |
| A reaction: Presumably they are 'impredicative' because they do not predicate a new quality in the definiens, but make use of the qualities already known. |
| 2435 | Psychology has to include the idea that mental processes are typically truth-preserving [Fodor] |
| Full Idea: A psychology that can't make sense of such facts as that mental processes are typically truth-preserving is ipso facto dead in the water. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §1.3) |
| 9987 | An aggregate in which order does not matter I call a 'set' [Bolzano] |
| Full Idea: An aggregate whose basic conception renders the arrangement of its members a matter of indifference, and whose permutation therefore produces no essential difference, I call a 'set'. | |
| From: Bernard Bolzano (Paradoxes of the Infinite [1846], §4), quoted by William W. Tait - Frege versus Cantor and Dedekind IX | |
| A reaction: The idea of 'sets' was emerging before Cantor formalised it, and clarified it by thinking about infinite sets. Nowadays we also have 'ordered' sets, which rather contradicts Bolzano, and we also expect the cardinality to be determinate. |
| 10098 | The 'power set' of A is all the subsets of A [George/Velleman] |
| Full Idea: The 'power set' of A is all the subsets of A. P(A) = {B : B ⊆ A}. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) |
| 10099 | The 'ordered pair' <a, b>, for two sets a and b, is the set {{a, b},{a}} [George/Velleman] |
| Full Idea: The 'ordered pair' <a, b>, for two sets a and b, is the set {{a, b},{a}}. The existence of this set is guaranteed by three applications of the Axiom of Pairing. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: See Idea 10100 for the Axiom of Pairing. |
| 10101 |
Cartesian Product A x B: the set of all ordered pairs |
| Full Idea: The 'Cartesian Product' of any two sets A and B is the set of all ordered pairs <a, b> in which a ∈ A and b ∈ B, and it is denoted as A x B. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) |
| 10103 | Grouping by property is common in mathematics, usually using equivalence [George/Velleman] |
| Full Idea: The idea of grouping together objects that share some property is a common one in mathematics, ...and the technique most often involves the use of equivalence relations. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) |
| 10104 | 'Equivalence' is a reflexive, symmetric and transitive relation; 'same first letter' partitions English words [George/Velleman] |
| Full Idea: A relation is an equivalence relation if it is reflexive, symmetric and transitive. The 'same first letter' is an equivalence relation on the set of English words. Any relation that puts a partition into clusters will be equivalence - and vice versa. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: This is a key concept in the Fregean strategy for defining numbers. |
| 10096 | Even the elements of sets in ZFC are sets, resting on the pure empty set [George/Velleman] |
| Full Idea: ZFC is a theory concerned only with sets. Even the elements of all of the sets studied in ZFC are also sets (whose elements are also sets, and so on). This rests on one clearly pure set, the empty set Φ. ..Mathematics only needs pure sets. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: This makes ZFC a much more metaphysically comfortable way to think about sets, because it can be viewed entirely formally. It is rather hard to disentangle a chair from the singleton set of that chair. |
| 10097 | Axiom of Extensionality: for all sets x and y, if x and y have the same elements then x = y [George/Velleman] |
| Full Idea: The Axiom of Extensionality says that for all sets x and y, if x and y have the same elements then x = y. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: This seems fine in pure set theory, but hits the problem of renates and cordates in the real world. The elements coincide, but the axiom can't tell you why they coincide. |
| 10100 | Axiom of Pairing: for all sets x and y, there is a set z containing just x and y [George/Velleman] |
| Full Idea: The Axiom of Pairing says that for all sets x and y, there is a set z containing x and y, and nothing else. In symbols: ∀x∀y∃z∀w(w ∈ z ↔ (w = x ∨ w = y)). | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: See Idea 10099 for an application of this axiom. |
| 17900 | The Axiom of Reducibility made impredicative definitions possible [George/Velleman] |
| Full Idea: The Axiom of Reducibility ...had the effect of making impredicative definitions possible. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) |
| 10109 | ZFC can prove that there is no set corresponding to the concept 'set' [George/Velleman] |
| Full Idea: Sets, unlike extensions, fail to correspond to all concepts. We can prove in ZFC that there is no set corresponding to the concept 'set' - that is, there is no set of all sets. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.4) | |
| A reaction: This is rather an important point for Frege. However, all concepts have extensions, but they may be proper classes, rather than precisely defined sets. |
| 10108 | As a reduction of arithmetic, set theory is not fully general, and so not logical [George/Velleman] |
| Full Idea: The problem with reducing arithmetic to ZFC is not that this theory is inconsistent (as far as we know it is not), but rather that is not completely general, and for this reason not logical. For example, it asserts the existence of sets. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.4) | |
| A reaction: Note that ZFC has not been proved consistent. |
| 2442 | Inferences are surely part of the causal structure of the world [Fodor] |
| Full Idea: Inferences are surely part of the causal structure of the world. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §3) |
| 10111 | Asserting Excluded Middle is a hallmark of realism about the natural world [George/Velleman] |
| Full Idea: A hallmark of our realist stance towards the natural world is that we are prepared to assert the Law of Excluded Middle for all statements about it. For all statements S, either S is true, or not-S is true. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.4) | |
| A reaction: Personally I firmly subscribe to realism, so I suppose I must subscribe to Excluded Middle. ...Provided the statement is properly formulated. Or does liking excluded middle lead me to realism? |
| 10129 | A 'model' is a meaning-assignment which makes all the axioms true [George/Velleman] |
| Full Idea: A 'model' of a theory is an assignment of meanings to the symbols of its language which makes all of its axioms come out true. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7) | |
| A reaction: If the axioms are all true, and the theory is sound, then all of the theorems will also come out true. |
| 10105 | Differences between isomorphic structures seem unimportant [George/Velleman] |
| Full Idea: Mathematicians tend to regard the differences between isomorphic mathematical structures as unimportant. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: This seems to be a pointer towards Structuralism as the underlying story in mathematics. The intrinsic character of so-called 'objects' seems unimportant. How theories map onto one another (and onto the world?) is all that matters? |
| 10119 | Consistency is a purely syntactic property, unlike the semantic property of soundness [George/Velleman] |
| Full Idea: Consistency is a purely syntactic property, unlike the semantic property of soundness. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6) |
| 10126 | A 'consistent' theory cannot contain both a sentence and its negation [George/Velleman] |
| Full Idea: If there is a sentence such that both the sentence and its negation are theorems of a theory, then the theory is 'inconsistent'. Otherwise it is 'consistent'. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7) |
| 10120 | Soundness is a semantic property, unlike the purely syntactic property of consistency [George/Velleman] |
| Full Idea: Soundness is a semantic property, unlike the purely syntactic property of consistency. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6) |
| 10127 | A 'complete' theory contains either any sentence or its negation [George/Velleman] |
| Full Idea: If there is a sentence such that neither the sentence nor its negation are theorems of a theory, then the theory is 'incomplete'. Otherwise it is 'complete'. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7) | |
| A reaction: Interesting questions are raised about undecidable sentences, irrelevant sentences, unknown sentences.... |
| 10106 | Rational numbers give answers to division problems with integers [George/Velleman] |
| Full Idea: We can think of rational numbers as providing answers to division problems involving integers. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: Cf. Idea 10102. |
| 10102 | The integers are answers to subtraction problems involving natural numbers [George/Velleman] |
| Full Idea: In defining the integers in set theory, our definition will be motivated by thinking of the integers as answers to subtraction problems involving natural numbers. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: Typical of how all of the families of numbers came into existence; they are 'invented' so that we can have answers to problems, even if we can't interpret the answers. It it is money, we may say the minus-number is a 'debt', but is it? Cf Idea 10106. |
| 10107 | Real numbers provide answers to square root problems [George/Velleman] |
| Full Idea: One reason for introducing the real numbers is to provide answers to square root problems. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: Presumably the other main reasons is to deal with problems of exact measurement. It is interesting that there seem to be two quite distinct reasons for introducing the reals. Cf. Ideas 10102 and 10106. |
| 9946 | Logicists say mathematics is applicable because it is totally general [George/Velleman] |
| Full Idea: The logicist idea is that if mathematics is logic, and logic is the most general of disciplines, one that applies to all rational thought regardless of its content, then it is not surprising that mathematics is widely applicable. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.2) | |
| A reaction: Frege was keen to emphasise this. You are left wondering why pure logic is applicable to the physical world. The only account I can give is big-time Platonism, or Pythagoreanism. Logic reveals the engine-room of nature, where the design is done. |
| 10856 | A truly infinite quantity does not need to be a variable [Bolzano] |
| Full Idea: A truly infinite quantity (for example, the length of a straight line, unbounded in either direction) does not by any means need to be a variable. | |
| From: Bernard Bolzano (Paradoxes of the Infinite [1846]), quoted by Brian Clegg - Infinity: Quest to Think the Unthinkable §10 | |
| A reaction: This is an important idea, followed up by Cantor, which relegated to the sidelines the view of infinity as simply something that could increase without limit. Personally I like the old view, but there is something mathematically stable about infinity. |
| 10125 | The classical mathematician believes the real numbers form an actual set [George/Velleman] |
| Full Idea: Unlike the intuitionist, the classical mathematician believes in an actual set that contains all the real numbers. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6) |
| 17899 | Second-order induction is stronger as it covers all concepts, not just first-order definable ones [George/Velleman] |
| Full Idea: The first-order version of the induction axiom is weaker than the second-order, because the latter applies to all concepts, but the first-order applies only to concepts definable by a formula in the first-order language of number theory. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7 n7) |
| 10128 | The Incompleteness proofs use arithmetic to talk about formal arithmetic [George/Velleman] |
| Full Idea: The idea behind the proofs of the Incompleteness Theorems is to use the language of Peano Arithmetic to talk about the formal system of Peano Arithmetic itself. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7) | |
| A reaction: The mechanism used is to assign a Gödel Number to every possible formula, so that all reasonings become instances of arithmetic. |
| 17902 | A successor is the union of a set with its singleton [George/Velleman] |
| Full Idea: For any set x, we define the 'successor' of x to be the set S(x) = x U {x}. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: This is the Fregean approach to successor, where the Dedekind approach takes 'successor' to be a primitive. Frege 1884:§76. |
| 10133 | Frege's Theorem shows the Peano Postulates can be derived from Hume's Principle [George/Velleman] |
| Full Idea: The derivability of Peano's Postulates from Hume's Principle in second-order logic has been dubbed 'Frege's Theorem', (though Frege would not have been interested, because he didn't think Hume's Principle gave an adequate definition of numebrs). | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.8 n1) | |
| A reaction: Frege said the numbers were the sets which were the extensions of the sets created by Hume's Principle. |
| 10130 | Set theory can prove the Peano Postulates [George/Velleman] |
| Full Idea: The Peano Postulates can be proven in ZFC. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7) |
| 10089 | Talk of 'abstract entities' is more a label for the problem than a solution to it [George/Velleman] |
| Full Idea: One might well wonder whether talk of abstract entities is less a solution to the empiricist's problem of how a priori knowledge is possible than it is a label for the problem. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Intro) | |
| A reaction: This pinpoints my view nicely. What the platonist postulates is remote, bewildering, implausible and useless! |
| 10131 | If mathematics is not about particulars, observing particulars must be irrelevant [George/Velleman] |
| Full Idea: As, in the logicist view, mathematics is about nothing particular, it is little wonder that nothing in particular needs to be observed in order to acquire mathematical knowledge. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002]) | |
| A reaction: At the very least we can say that no one would have even dreamt of the general system of arithmetic is they hadn't had experience of the particulars. Frege thought generality ensured applicability, but extreme generality might entail irrelevance. |
| 10092 | In the unramified theory of types, the types are objects, then sets of objects, sets of sets etc. [George/Velleman] |
| Full Idea: In the unramified theory of types, all objects are classified into a hierarchy of types. The lowest level has individual objects that are not sets. Next come sets whose elements are individuals, then sets of sets, etc. Variables are confined to types. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: The objects are Type 0, the basic sets Type 1, etc. |
| 10094 | The theory of types seems to rule out harmless sets as well as paradoxical ones. [George/Velleman] |
| Full Idea: The theory of types seems to rule out harmless sets as well as paradoxical ones. If a is an individual and b is a set of individuals, then in type theory we cannot talk about the set {a,b}. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: Since we cheerfully talk about 'Cicero and other Romans', this sounds like a rather disasterous weakness. |
| 10095 | Type theory has only finitely many items at each level, which is a problem for mathematics [George/Velleman] |
| Full Idea: A problem with type theory is that there are only finitely many individuals, and finitely many sets of individuals, and so on. The hierarchy may be infinite, but each level is finite. Mathematics required an axiom asserting infinitely many individuals. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) | |
| A reaction: Most accounts of mathematics founder when it comes to infinities. Perhaps we should just reject them? |
| 17901 | Type theory prohibits (oddly) a set containing an individual and a set of individuals [George/Velleman] |
| Full Idea: If a is an individual and b is a set of individuals, then in the theory of types we cannot talk about the set {a,b}, since it is not an individual or a set of individuals, ...but it is hard to see what harm can come from it. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3) |
| 10114 | Bounded quantification is originally finitary, as conjunctions and disjunctions [George/Velleman] |
| Full Idea: In the first instance all bounded quantifications are finitary, for they can be viewed as abbreviations for conjunctions and disjunctions. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6) | |
| A reaction: This strikes me as quite good support for finitism. The origin of a concept gives a good guide to what it really means (not a popular view, I admit). When Aristotle started quantifying, I suspect of he thought of lists, not totalities. |
| 10134 | Much infinite mathematics can still be justified finitely [George/Velleman] |
| Full Idea: It is possible to use finitary reasoning to justify a significant part of infinitary mathematics. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.8) | |
| A reaction: This might save Hilbert's project, by gradually accepting into the fold all the parts which have been giving a finitist justification. |
| 10123 | The intuitionists are the idealists of mathematics [George/Velleman] |
| Full Idea: The intuitionists are the idealists of mathematics. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6) |
| 10124 | Gödel's First Theorem suggests there are truths which are independent of proof [George/Velleman] |
| Full Idea: For intuitionists, truth is not independent of proof, but this independence is precisely what seems to be suggested by Gödel's First Incompleteness Theorem. | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.8) | |
| A reaction: Thus Gödel was worse news for the Intuitionists than he was for Hilbert's Programme. Gödel himself responded by becoming a platonist about his unprovable truths. |
| 2462 | Control of belief is possible if you know truth conditions and what causes beliefs [Fodor] |
| Full Idea: Premeditated cognitive management is possible if knowing the contents of one's thoughts would tell you what would make them true and what would cause you to have them. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: I love the idea of 'cognitive management'. Since belief is fairly involuntary, I subject myself to the newspapers, books, TV and conversation which will create the style of beliefs to which I aspire. Why? |
| 2461 | An experiment is a deliberate version of what informal thinking does all the time [Fodor] |
| Full Idea: Experimentation is an occasional and more or less self-conscious exercise in what informal thinking does all the time without thinking about it. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) |
| 2454 | We can deliberately cause ourselves to have true thoughts - hence the value of experiments [Fodor] |
| Full Idea: A creature that knows what makes its thoughts true and what would cause it to have them, could therefore cause itself to have true thoughts. …This would explain why experimentation is so close to the heart of our cognitive style. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) |
| 2455 | Interrogation and experiment submit us to having beliefs caused [Fodor] |
| Full Idea: You can put yourself into a situation where you may be caused to believe that P. Putting a question to someone who is in the know is one species of this behaviour, and putting a question to Nature (an experiment) is another. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) |
| 2460 | Participation in an experiment requires agreement about what the outcome will mean [Fodor] |
| Full Idea: To be in the audience for an experiment you have to believe what the experimenter believes about what the outcome would mean, but not necessarily what the outcome will be. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) |
| 2458 | Theories are links in the causal chain between the environment and our beliefs [Fodor] |
| Full Idea: Theories function as links in the causal chains that run from environmental outcomes to the beliefs that they cause the inquirer to have. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) |
| 2443 | I say psychology is intentional, semantics is informational, and thinking is computation [Fodor] |
| Full Idea: I hold that psychological laws are intentional, that semantics is purely informational, and that thinking is computation (and that it is possible to hold all of these assumptions at once). | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: When he puts it baldly like that, it doesn't sound terribly persuasive. Thinking is 'computation'? Raw experience is irrelevant? What is it 'like' to spot an interesting connection between two propositions or concepts? It's not like adding 7 and 5. |
| 2453 | We are probably the only creatures that can think about our own thoughts [Fodor] |
| Full Idea: I think it is likely that we are the only creatures that can think about the contents of our thoughts. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: I think this is a major idea. If you ask me the traditional question - what is the essential difference between us and other animals? - this is my answer (not language, or reason). We are the metathinkers. |
| 2446 | Cartesians consider interaction to be a miracle [Fodor] |
| Full Idea: The Cartesian view is that the interaction problem does arise, but is unsolvable because interaction is miraculous. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: A rather unsympathetic statement of the position. Cartesians might think that God could explain to us how interaction works. Cartesians are not mysterians, I think, but they see no sign of any theory of interaction. |
| 2445 | Semantics v syntax is the interaction problem all over again [Fodor] |
| Full Idea: The question how mental representations could be both semantic, like propositions, and causal, like rocks, trees, and neural firings, is arguably just the interaction problem all over again. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: Interesting way of presenting the problem. If you seem to be confronting the interaction problem, you have probably drifted into a bogus dualist way of thinking. Retreat, and reformulate you questions and conceptual apparatus, till the question vanishes. |
| 2464 | Type physicalism equates mental kinds with physical kinds [Fodor] |
| Full Idea: Type physicalism is, roughly, the doctrine that psychological kinds are identical to neurological kinds. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], App A n.1) | |
| A reaction: This gets my general support, leaving open the nature of 'kinds'. Presumably the identity is strict, as in 'Hesperus is identical to Phosphorus'. It seems unlikely that if you and I think the 'same' thought, that we have strictly identical brain states. |
| 2447 | Hume has no theory of the co-ordination of the mind [Fodor] |
| Full Idea: What Hume didn't see was that the causal and representational properties of mental symbols have somehow to be coordinated if the coherence of mental life is to be accounted for. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: Certainly the idea that it all somehow becomes magic at the point where the brain represents the world is incoherent - but it is a bit magical. How can the whole of my garden be in my brain? Weird. |
| 2440 | Propositional attitudes are propositions presented in a certain way [Fodor] |
| Full Idea: Propositional attitudes are really three-place relations, between a creature, a proposition, and a mode of presentation (which are sentences of Mentalese). | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §2.II) | |
| A reaction: I'm not sure about 'really'! Why do we need a creature? Isn't 'hoping it will rain' a propositional attitude which some creature may or may not have? Fodor wants it to be physical, but it's abstract? |
| 2450 | Rationality has mental properties - autonomy, productivity, experiment [Fodor] |
| Full Idea: Mentalism isn't gratuitous; you need it to explain rationality. Mental causation buys you behaviours that are unlike reflexes in at least three ways: they're autonomous, they're productive, and they're experimental. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: He makes his three ways sound all-or-nothing, which is (I believe) the single biggest danger when thinking about the mind. "Either you are conscious, or you are not..." |
| 2437 | XYZ (Twin Earth 'water') is an impossibility [Fodor] |
| Full Idea: There isn't any XYZ, and there couldn't be any, and so we don't have to worry about it. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §2.I) | |
| A reaction: Jadeite and Nephrite are real enough, which are virtually indistinguishable variants of jade. You just need Twin Jewellers instead of Twin Earths. We could build them, and employ twins to work there. |
| 2441 | Truth conditions require a broad concept of content [Fodor] |
| Full Idea: We need the idea of broad content to make sense of the fact that thoughts have the truth-conditions that they do. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §2.II) | |
| A reaction: There seems to be (as Dummett points out) a potential circularity here, as you can hardly know the truth-conditions of something if you don't already know its content. |
| 3114 | Concepts aren't linked to stuff; they are what is caused by stuff [Fodor] |
| Full Idea: If the words of 'Swamp Man' (spontaneously created, with concepts) are about XYZ on Twin Earth, it is not because he's causally connected to the stuff, but because XYZ would cause his 'water' tokens (in the absence of H2O). | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], App B) | |
| A reaction: The sight of the Eiffel tower causes my 'France' tokens, so is my word "France" about the Eiffel Tower? What would cause my 'nothing' tokens? |
| 2452 | Knowing the cause of a thought is almost knowing its content [Fodor] |
| Full Idea: If you know the content of a thought, you know quite a lot about what would cause you to have it. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: I'm not sure where this fits into the great jigsaw of the mind, but it strikes me as an acute and important observation. The truth of a thought is not essential to make you have it. Ask Othello. |
| 2432 | Is content basically information, fixed externally? [Fodor] |
| Full Idea: I assume intentional content reduces (in some way) to information. …The content of a thought depends on its external relations; on the way that the thought is related to the world, not the way that it is related to other thoughts. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §1.2) | |
| A reaction: Does this make Fodor a 'weak' functionalist? The 'strong' version would say a thought is merely a location in a flow diagram, but Fodor's 'mentalism' includes a further 'content' in each diagram box. |
| 10110 | Corresponding to every concept there is a class (some of them sets) [George/Velleman] |
| Full Idea: Corresponding to every concept there is a class (some classes will be sets, the others proper classes). | |
| From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.4) |
| 2438 | In the information view, concepts are potentials for making distinctions [Fodor] |
| Full Idea: Semantics, according to the informational view, is mostly about counterfactuals; what counts for the identity of my concepts is not what I do distinguish but what I could distinguish if I cared to (even using instruments and experts). | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §2.I) | |
| A reaction: We all differ in our discriminations (and awareness of expertise), so our concepts would differ, which is bad news for communication (see Idea 223). The view has some plausibility, though. |
| 2439 | Semantic externalism says the concept 'elm' needs no further beliefs or inferences [Fodor] |
| Full Idea: It is the essence of semantic externalism that there is nothing that you have to believe, there are no inferences that you have to accept, to have the concept 'elm'. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §2.I) | |
| A reaction: [REMINDER: broad content is filed in 18.C.7, under 'Thought' rather than under language. That is because I am a philospher of thought, rather than of language. |
| 2457 | If meaning is information, that establishes the causal link between the state of the world and our beliefs [Fodor] |
| Full Idea: It is the causal connection between the state of the world and the contents of beliefs that the reduction of meaning to information is designed to insure. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: I'm not clear why characterising the contents of a belief in terms of its information has to amount to a 'reduction'. A cup of tea isn't reduced to tea. Connections imply duality. |
| 2451 | To know the content of a thought is to know what would make it true [Fodor] |
| Full Idea: If you know the content of a thought, you thereby know what would make the thought true. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: The truthmaker might by physically impossible, and careful thought might show it to be contradictory - but that wouldn't destroy the meaning. |
| 2433 | For holists no two thoughts are ever quite the same, which destroys faith in meaning [Fodor] |
| Full Idea: If what you are thinking depends on all of what you believe, then nobody ever thinks the same thing twice. …That is why so many semantic holists (Quine, Putnam, Rorty, Churchland, probably Wittgenstein) end up being semantic eliminativists. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §1.2b) | |
| A reaction: If linguistic holism is nonsense, this is easily settled. What I say about breakfast is not changed by reading some Gibbon yesterday. |
| 2436 | It is claimed that reference doesn't fix sense (Jocasta), and sense doesn't fix reference (Twin Earth) [Fodor] |
| Full Idea: The standard view is that Frege cases [knowing Jocasta but not mother] show that reference doesn't determine sense, and Twin cases [knowing water but not H2O] show that sense doesn't determine reference. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §1.3) | |
| A reaction: How about 'references don't contain much information', and 'descriptions may not fix what they are referring to'? Simple really. |
| 2434 | Broad semantics holds that the basic semantic properties are truth and denotation [Fodor] |
| Full Idea: Broad semantic theories generally hold that the basic semantic properties of thoughts are truth and denotation. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §1.2b) | |
| A reaction: I think truth and denotation are the basic semantic properties, but I am dubious about whole-hearted broad semantic theories, so I seem to have gone horribly wrong somewhere. |
| 2459 | Externalist semantics are necessary to connect the contents of beliefs with how the world is [Fodor] |
| Full Idea: You need an externalist semantics to explain why the contents of beliefs should have anything to do with how the world is. | |
| From: Jerry A. Fodor (The Elm and the Expert [1993], §4) | |
| A reaction: Since externalist semantics only emerged in the 1970s, that implies that no previous theory had any notion that language had some connection to how the world is. Eh? |