68 ideas
| 13466 | We are all post-Kantians, because he set the current agenda for philosophy [Hart,WD] |
| Full Idea: We are all post-Kantians, ...because Kant set an agenda for philosophy that we are still working through. | |
| From: William D. Hart (The Evolution of Logic [2010], 2) | |
| A reaction: Hart says that the main agenda is set by Kant's desire to defend the principle of sufficient reason against Hume's attack on causation. I would take it more generally to be the assessment of metaphysics, and of a priori knowledge. |
| 13477 | The problems are the monuments of philosophy [Hart,WD] |
| Full Idea: The real monuments of philosophy are its problems. | |
| From: William D. Hart (The Evolution of Logic [2010], 2) | |
| A reaction: Presumably he means '....rather than its solutions'. No other subject would be very happy with that sort of claim. Compare Idea 8243. A complaint against analytic philosophy is that it has achieved no consensus at all. |
| 13515 | To study abstract problems, some knowledge of set theory is essential [Hart,WD] |
| Full Idea: By now, no education in abstract pursuits is adequate without some familiarity with sets. | |
| From: William D. Hart (The Evolution of Logic [2010], 10) | |
| A reaction: A heart-sinking observation for those who aspire to study metaphysics and modality. The question is, what will count as 'some' familiarity? Are only professional logicians now allowed to be proper philosophers? |
| 13469 | Tarski showed how we could have a correspondence theory of truth, without using 'facts' [Hart,WD] |
| Full Idea: It is an ancient and honourable view that truth is correspondence to fact; Tarski showed us how to do without facts here. | |
| From: William D. Hart (The Evolution of Logic [2010], 2) | |
| A reaction: This is a very interesting spin on Tarski, who certainly seems to endorse the correspondence theory, even while apparently inventing a new 'semantic' theory of truth. It is controversial how far Tarski's theory really is a 'correspondence' theory. |
| 13504 | Truth for sentences is satisfaction of formulae; for sentences, either all sequences satisfy it (true) or none do [Hart,WD] |
| Full Idea: We explain truth for sentences in terms of satisfaction of formulae. The crux here is that for a sentence, either all sequences satisfy it or none do (with no middle ground). For formulae, some sequences may satisfy it and others not. | |
| From: William D. Hart (The Evolution of Logic [2010], 4) | |
| A reaction: This is the hardest part of Tarski's theory of truth to grasp. |
| 13503 | A first-order language has an infinity of T-sentences, which cannot add up to a definition of truth [Hart,WD] |
| Full Idea: In any first-order language, there are infinitely many T-sentences. Since definitions should be finite, the agglomeration of all the T-sentences is not a definition of truth. | |
| From: William D. Hart (The Evolution of Logic [2010], 4) | |
| A reaction: This may be a warning shot aimed at Davidson's extensive use of Tarski's formal account in his own views on meaning in natural language. |
| 13500 | Conditional Proof: infer a conditional, if the consequent can be deduced from the antecedent [Hart,WD] |
| Full Idea: A 'conditional proof' licenses inferences to a conditional from a deduction of its consequent from its antecedent. | |
| From: William D. Hart (The Evolution of Logic [2010], 4) | |
| A reaction: That is, a proof can be enshrined in an arrow. |
| 13502 | ∃y... is read as 'There exists an individual, call it y, such that...', and not 'There exists a y such that...' [Hart,WD] |
| Full Idea: When a quantifier is attached to a variable, as in '∃(y)....', then it should be read as 'There exists an individual, call it y, such that....'. One should not read it as 'There exists a y such that...', which would attach predicate to quantifier. | |
| From: William D. Hart (The Evolution of Logic [2010], 4) | |
| A reaction: The point is to make clear that in classical logic the predicates attach to the objects, and not to some formal component like a quantifier. |
| 13456 | Set theory articulates the concept of order (through relations) [Hart,WD] |
| Full Idea: It is set theory, and more specifically the theory of relations, that articulates order. | |
| From: William D. Hart (The Evolution of Logic [2010]) | |
| A reaction: It would seem that we mainly need set theory in order to talk accurately about order, and about infinity. The two come together in the study of the ordinal numbers. |
| 13497 | Nowadays ZFC and NBG are the set theories; types are dead, and NF is only useful for the whole universe [Hart,WD] |
| Full Idea: The theory of types is a thing of the past. There is now nothing to choose between ZFC and NBG (Neumann-Bernays-Gödel). NF (Quine's) is a more specialized taste, but is a place to look if you want the universe. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) |
| 13443 | ∈ relates across layers, while ⊆ relates within layers [Hart,WD] |
| Full Idea: ∈ relates across layers (Plato is a member of his unit set and the set of people), while ⊆ relates within layers (the singleton of Plato is a subset of the set of people). This distinction only became clear in the 19th century. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) | |
| A reaction: Getting these two clear may be the most important distinction needed to understand how set theory works. |
| 13442 | Without the empty set we could not form a∩b without checking that a and b meet [Hart,WD] |
| Full Idea: Without the empty set, disjoint sets would have no intersection, and we could not form a∩b without checking that a and b meet. This is an example of the utility of the empty set. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) | |
| A reaction: A novice might plausibly ask why there should be an intersection for every pair of sets, if they have nothing in common except for containing this little puff of nothingness. But then what do novices know? |
| 13493 | In the modern view, foundation is the heart of the way to do set theory [Hart,WD] |
| Full Idea: In the second half of the twentieth century there emerged the opinion that foundation is the heart of the way to do set theory. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) | |
| A reaction: It is foundation which is the central axiom of the iterative conception of sets, where each level of sets is built on previous levels, and they are all 'well-founded'. |
| 13495 | Foundation Axiom: an nonempty set has a member disjoint from it [Hart,WD] |
| Full Idea: The usual statement of Foundation is that any nonempty set has a member disjoint from it. This phrasing is ordinal-free and closer to the primitives of ZFC. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) |
| 13461 | We can choose from finite and evident sets, but not from infinite opaque ones [Hart,WD] |
| Full Idea: When a set is finite, we can prove it has a choice function (∀x x∈A → f(x)∈A), but we need an axiom when A is infinite and the members opaque. From infinite shoes we can pick a left one, but from socks we need the axiom of choice. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) | |
| A reaction: The socks example in from Russell 1919:126. |
| 13462 | With the Axiom of Choice every set can be well-ordered [Hart,WD] |
| Full Idea: It follows from the Axiom of Choice that every set can be well-ordered. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) | |
| A reaction: For 'well-ordered' see Idea 13460. Every set can be ordered with a least member. |
| 13516 | If we accept that V=L, it seems to settle all the open questions of set theory [Hart,WD] |
| Full Idea: It has been said (by Burt Dreben) that the only reason set theorists do not generally buy the view that V = L is that it would put them out of business by settling their open questions. | |
| From: William D. Hart (The Evolution of Logic [2010], 10) | |
| A reaction: Hart says V=L breaks with the interative conception of sets at level ω+1, which is countable is the constructible view, but has continuum many in the cumulative (iterative) hierarch. The constructible V=L view is anti-platonist. |
| 13441 | Naïve set theory has trouble with comprehension, the claim that every predicate has an extension [Hart,WD] |
| Full Idea: 'Comprehension' is the assumption that every predicate has an extension. Naïve set theory is the theory whose axioms are extensionality and comprehension, and comprehension is thought to be its naivety. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) | |
| A reaction: This doesn't, of course, mean that there couldn't be a more modest version of comprehension. The notorious difficulty come with the discovery of self-referring predicates which can't possibly have extensions. |
| 13494 | The iterative conception may not be necessary, and may have fixed points or infinitely descending chains [Hart,WD] |
| Full Idea: That the iterative sets suffice for most of ZFC does not show they are necessary, nor is it evident that the set of operations has no fixed points (as 0 is a fixed point for square-of), and no infinitely descending chains (like negative integers). | |
| From: William D. Hart (The Evolution of Logic [2010], 3) | |
| A reaction: People don't seem to worry that they aren't 'necessary', and further measures are possible to block infinitely descending chains. |
| 13457 | A 'partial ordering' is irreflexive and transitive; the sets are ordered, but not the subsets [Hart,WD] |
| Full Idea: We say that a binary relation R 'partially orders' a field A just in case R is irreflexive (so that nothing bears R to itself) and transitive. When the set is {a,b}, its subsets {a} and {b} are incomparable in a partial ordering. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) |
| 13458 | A partial ordering becomes 'total' if any two members of its field are comparable [Hart,WD] |
| Full Idea: A partial ordering is a 'total ordering' just in case any two members of its field are comparable, that is, either a is R to b, or b is R to a, or a is b. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) | |
| A reaction: See Idea 13457 for 'partial ordering'. The three conditions are known as the 'trichotomy' condition. |
| 13460 | 'Well-ordering' must have a least member, so it does the natural numbers but not the integers [Hart,WD] |
| Full Idea: A total order 'well-orders' its field just in case any nonempty subset B of its field has an R-least member, that is, there is a b in B such that for any a in B different from b, b bears R to a. So less-than well-orders natural numbers, but not integers. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) | |
| A reaction: The natural numbers have a starting point, but the integers are infinite in both directions. In plain English, an order is 'well-ordered' if there is a starting point. |
| 13490 | Von Neumann defines α<β as α∈β [Hart,WD] |
| Full Idea: One of the glories of Von Neumann's theory of numbers is to define α < β to mean that α ∈ β. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) |
| 13536 | Skolem did not believe in the existence of uncountable sets [Skolem] |
| Full Idea: Skolem did not believe in the existence of uncountable sets. | |
| From: Thoralf Skolem (works [1920], 5.3) | |
| A reaction: Kit Fine refers somewhere to 'unrepentent Skolemites' who still hold this view. |
| 13481 | Maybe sets should be rethought in terms of the even more basic categories [Hart,WD] |
| Full Idea: Some have claimed that sets should be rethought in terms of still more basic things, categories. | |
| From: William D. Hart (The Evolution of Logic [2010], 2) | |
| A reaction: [He cites F.William Lawvere 1966] It appears to the the context of foundations for mathematics that he has in mind. |
| 13258 | The 'aggregative' objections says mereology gets existence and location of objects wrong [Koslicki] |
| Full Idea: The 'aggregative' objection to classical extensional mereology is that it assigns simply the wrong, set-like conditions of existence and spatio-temporal location to ordinary material objects. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 5.1) | |
| A reaction: [She attributes this to Kit Fine] The point is that there is more to a whole than just some parts, otherwise you could scatter the parts across the globe (or even across time) and claim that the object still existed. It's obvious really. |
| 13288 | Consequence is truth-preserving, either despite substitutions, or in all interpretations [Koslicki] |
| Full Idea: Two conceptions of logical consequence: a substitutional account, where no substitution of non-logical terms for others (of the right syntactic category) produce true premises and false conclusions; and model theory, where no interpretation can do it. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 9.3.2 n8) | |
| A reaction: [compressed] |
| 14506 | 'Roses are red; therefore, roses are colored' seems truth-preserving, but not valid in a system [Koslicki] |
| Full Idea: 'Roses are red; therefore, roses are colored' may be necessarily truth-preserving, but it would not be classified as logically valid by standard systems of logic. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 9.3.2) |
| 13506 | The universal quantifier can't really mean 'all', because there is no universal set [Hart,WD] |
| Full Idea: All the main set theories deny that there is a set of which everything is a member. No interpretation has a domain with everything in it. So the universal quantifier never gets to mean everything all at once; 'all' does not mean all. | |
| From: William D. Hart (The Evolution of Logic [2010], 4) | |
| A reaction: Could you have an 'uncompleted' universal set, in the spirit of uncompleted infinities? In ordinary English we can talk about 'absolutely everything' - we just can't define a set of everything. Must we 'define' our domain? |
| 13512 | Modern model theory begins with the proof of Los's Conjecture in 1962 [Hart,WD] |
| Full Idea: The beginning of modern model theory was when Morley proved Los's Conjecture in 1962 - that a complete theory in a countable language categorical in one uncountable cardinal is categorical in all. | |
| From: William D. Hart (The Evolution of Logic [2010], 9) |
| 13505 | Model theory studies how set theory can model sets of sentences [Hart,WD] |
| Full Idea: Modern model theory investigates which set theoretic structures are models for which collections of sentences. | |
| From: William D. Hart (The Evolution of Logic [2010], 4) | |
| A reaction: So first you must choose your set theory (see Idea 13497). Then you presumably look at how to formalise sentences, and then look at the really tricky ones, many of which will involve various degrees of infinity. |
| 13511 | Model theory is mostly confined to first-order theories [Hart,WD] |
| Full Idea: There is no developed methematics of models for second-order theories, so for the most part, model theory is about models for first-order theories. | |
| From: William D. Hart (The Evolution of Logic [2010], 9) |
| 13513 | Models are ways the world might be from a first-order point of view [Hart,WD] |
| Full Idea: Models are ways the world might be from a first-order point of view. | |
| From: William D. Hart (The Evolution of Logic [2010], 9) |
| 13496 | First-order logic is 'compact': consequences of a set are consequences of a finite subset [Hart,WD] |
| Full Idea: First-order logic is 'compact', which means that any logical consequence of a set (finite or infinite) of first-order sentences is a logical consequence of a finite subset of those sentences. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) |
| 13484 | Berry's Paradox: we succeed in referring to a number, with a term which says we can't do that [Hart,WD] |
| Full Idea: Berry's Paradox: by the least number principle 'the least number denoted by no description of fewer than 79 letters' exists, but we just referred to it using a description of 77 letters. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) | |
| A reaction: I struggle with this. If I refer to 'an object to which no human being could possibly refer', have I just referred to something? Graham Priest likes this sort of idea. |
| 13482 | The Burali-Forti paradox is a crisis for Cantor's ordinals [Hart,WD] |
| Full Idea: The Burali-Forti Paradox was a crisis for Cantor's theory of ordinal numbers. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) |
| 13507 | The machinery used to solve the Liar can be rejigged to produce a new Liar [Hart,WD] |
| Full Idea: In effect, the machinery introduced to solve the liar can always be rejigged to yield another version the liar. | |
| From: William D. Hart (The Evolution of Logic [2010], 4) | |
| A reaction: [He cites Hans Herzberger 1980-81] The machinery is Tarski's device of only talking about sentences of a language by using a 'metalanguage'. |
| 13459 | The less-than relation < well-orders, and partially orders, and totally orders the ordinal numbers [Hart,WD] |
| Full Idea: We can show (using the axiom of choice) that the less-than relation, <, well-orders the ordinals, ...and that it partially orders the ordinals, ...and that it totally orders the ordinals. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) |
| 13491 | The axiom of infinity with separation gives a least limit ordinal ω [Hart,WD] |
| Full Idea: The axiom of infinity with separation yields a least limit ordinal, which is called ω. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) |
| 13463 | There are at least as many infinite cardinals as transfinite ordinals (because they will map) [Hart,WD] |
| Full Idea: Since we can map the transfinite ordinals one-one into the infinite cardinals, there are at least as many infinite cardinals as transfinite ordinals. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) |
| 13492 | Von Neumann's ordinals generalise into the transfinite better, because Zermelo's ω is a singleton [Hart,WD] |
| Full Idea: It is easier to generalize von Neumann's finite ordinals into the transfinite. All Zermelo's nonzero finite ordinals are singletons, but if ω were a singleton it is hard to see how if could fail to be the successor of its member and so not a limit. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) |
| 13446 | 19th century arithmetization of analysis isolated the real numbers from geometry [Hart,WD] |
| Full Idea: The real numbers were not isolated from geometry until the arithmetization of analysis during the nineteenth century. | |
| From: William D. Hart (The Evolution of Logic [2010], 1) |
| 13509 | We can establish truths about infinite numbers by means of induction [Hart,WD] |
| Full Idea: Mathematical induction is a way to establish truths about the infinity of natural numbers by a finite proof. | |
| From: William D. Hart (The Evolution of Logic [2010], 5) | |
| A reaction: If there are truths about infinities, it is very tempting to infer that the infinities must therefore 'exist'. A nice, and large, question in philosophy is whether there can be truths without corresponding implications of existence. |
| 13474 | Euclid has a unique parallel, spherical geometry has none, and saddle geometry has several [Hart,WD] |
| Full Idea: There is a familiar comparison between Euclid (unique parallel) and 'spherical' geometry (no parallel) and 'saddle' geometry (several parallels). | |
| From: William D. Hart (The Evolution of Logic [2010], 2) |
| 14505 | Some questions concern mathematical entities, rather than whole structures [Koslicki] |
| Full Idea: Those who hold that not all mathematical questions can be concerned with structural matters can point to 'why are π or e transcendental?' or 'how are the prime numbers distributed?' as questions about particular features in the domain. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 9.3.1 n6) | |
| A reaction: [She cites Mac Lane on this] The reply would have to be that we only have those particular notions because we have abstracted them from structures, as in deriving π for circles. |
| 13471 | Mathematics makes existence claims, but philosophers usually say those are never analytic [Hart,WD] |
| Full Idea: The thesis that no existence proposition is analytic is one of the few constants in philosophical consciences, but there are many existence claims in mathematics, such as the infinity of primes, five regular solids, and certain undecidable propositions. | |
| From: William D. Hart (The Evolution of Logic [2010], 2) |
| 13488 | Mass words do not have plurals, or numerical adjectives, or use 'fewer' [Hart,WD] |
| Full Idea: Jespersen calls a noun a mass word when it has no plural, does not take numerical adjectives, and does not take 'fewer'. | |
| From: William D. Hart (The Evolution of Logic [2010], 3) | |
| A reaction: Jespersen was a great linguistics expert. |
| 13289 | Structures have positions, constituent types and number, and some invariable parts [Koslicki] |
| Full Idea: Structures make available positions or places for objects, and place restraints on the type of constituent, and on their configuration. ...These lead to restrictions on the number of objects, and on which parts of the structure are invariable. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 9.6) | |
| A reaction: [compressed] That's a pretty good first shot at saying what a structure is, which I have so far not discovered any other writer willing to do. I take this to be an exploration of what Aristotle meant by 'form'. |
| 14501 | 'Categorical' properties exist in the actual world, and 'hypothetical' properties in other worlds [Koslicki] |
| Full Idea: The 'categorical' properties are roughly those that concern what goes on in the actual world; the properties excluded from that family are the 'hypothetical' ones, which concern what goes on in other worlds. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 3.2.3.1) | |
| A reaction: The awkward guest at this little party is the 'dispositional' properties, which are held to exist in the actual world, but have implications for other worlds. I'm a fan of them. |
| 14495 | I aim to put the notion of structure or form back into the concepts of part, whole and object [Koslicki] |
| Full Idea: My project is to put the notion of structure or form squarely back at the center of any adequate account of the notion of part, whole and object. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], Intro) | |
| A reaction: Excellent. It is the fault of logicians, who presumably can't cope with such elusive and complex concepts, that we have ended up with objects as lists of things or properties, or quantifications over them. |
| 13264 | If a whole is just a structure, a dinner party wouldn't need the guests to turn up [Koslicki] |
| Full Idea: If a whole is just a structure, we wonder how the guests could really be part of the dinner party seating structure, when the complex whole is fully exhausted by the structure that specifies the slots. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 4.2.2) | |
| A reaction: This cuts both ways. A dinner party may necessarily require guests, but the seating plan can be specified in the absence of any guests, who may never turn up. A seating plan is not a dinner party. Perhaps we have two objects here. |
| 14497 | The clay is just a part of the statue (its matter); the rest consists of its form or structure [Koslicki] |
| Full Idea: That objects are compounds of matter and form yields a solution to the Problem of Constitution: the clay is merely a proper part of the statue (viz. its matter); the 'remainder' of the statue is its formal or structural components which distinguish it. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], Info) | |
| A reaction: Thus philosophers have thought that it might consist of two objects because they have failed to grasp what an 'object' is. I would add that we need to mention 'essence', so that the statue can survive minor modifications. This is the solution! |
| 13280 | Statue and clay differ in modal and temporal properties, and in constitution [Koslicki] |
| Full Idea: The statue and the clay appear to differ in modal properties (such as being able to survive squashing), and temporal properties (coming into existence after the lump of clay), and in constitution (only the statue is constituted of the clay). | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 7.2.7.2) | |
| A reaction: I think the modal properties are the biggest problem here. You can't say a thing and its constitution are different objects, as they are necessarily connected. Structure comes into existence at t, but the structure isn't the whole object. |
| 14496 | Structure or form are right at the centre of modern rigorous modes of enquiry [Koslicki] |
| Full Idea: The notion of structure or form, far from being a mysterious and causally inert invention of philosophers, lies at the very center of many scientific and other rigorous endeavours, such as mathematics, logic, linguistics, chemistry and music. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], Intro) | |
| A reaction: This echoes my own belief exactly, and places Aristotle at the centre of the modern stage. Her list of subjects is intriguing, and will need a bit of thought. |
| 13279 | There are at least six versions of constitution being identity [Koslicki] |
| Full Idea: The view that constitution is identity has many versions: eliminativism (van Inwagen), identity relative to time (Gallois), identity relativized to sort (Geach), four-dimensionalism (Lewis, Sider), contingent identity (Gibbard), dominant kinds (Burke). | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 7.2.7.2 n17) | |
| A reaction: [she offers other names- useful footnote] Eliminativism says there is no identity. Gallois's view is Heraclitus. Geach seems to deny nature, since sorts are partly conventional. 4-D, nah! Gibbard: it could be the thing but lack its identity? Kinds wrong. |
| 14498 | For three-dimensionalist parthood must be a three-place relation, including times [Koslicki] |
| Full Idea: Parthood (for the three-dimensionalist) must be a three-place relation between pairs of objects and times, not the timeless two-place relation at work in the original Calculus of Individuals. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 2.2) |
| 13283 | The parts may be the same type as the whole, like a building made of buildings [Koslicki] |
| Full Idea: A building may be composed of proper parts which are themselves buildings; a particular pattern may be composed of proper parts which are themselves patterns (even the same pattern, on a smaller scale). | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 7.2.12) | |
| A reaction: This strikes me as a rather important observation, if you are (erroneously) trying to establish the identity of a thing simply by categorising its type. |
| 13266 | Wholes in modern mereology are intended to replace sets, so they closely resemble them [Koslicki] |
| Full Idea: The modern theory of parts and wholes was intended primarily to replace set theory; in this way, wholes came out looking as much like sets as they possibly could, without set theory's commitment to an infinite hierarchy of abstract objects. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], Intro) | |
| A reaction: A very nice clarificatory remark, which explains well this rather baffling phenomenon of people who think there is nothing more to a whole than a pile of parts, as if a scrap heap were the same as a fleet of motor cars. |
| 14500 | Wholes are entities distinct from their parts, and have different properties [Koslicki] |
| Full Idea: A commitment to wholes is a commitment to entities that are numerically distinct from their parts (by Leibniz's Law, they don't share all of their properties - the parts typically exist, but the whole doesn't, prior to its creation). | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 3.1) | |
| A reaction: Presumably in classical mereology no act of 'creation' is needed, since all the parts in the universe already form all the possible wholes into which they might combine, however bizarrely. |
| 13281 | Wholes are not just their parts; a whole is an entity distinct from the proper parts [Koslicki] |
| Full Idea: In my approach (as in that of Plato and Aristotle), wholes are in no way identified with parts; rather, a commitment to wholes is a commitment to entities numerically distinct from their proper parts. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 7.2.11) | |
| A reaction: Calling the whole an 'entity' doesn't seem to capture it. She seems to think there are some extra parts, in addition to the material parts, that make something a whole. I think this might be a category mistake. A structure is an abstraction. |
| 13480 | Fregean self-evidence is an intrinsic property of basic truths, rules and definitions [Hart,WD] |
| Full Idea: The conception of Frege is that self-evidence is an intrinsic property of the basic truths, rules, and thoughts expressed by definitions. | |
| From: William D. Hart (The Evolution of Logic [2010], p.350) | |
| A reaction: The problem is always that what appears to be self-evident may turn out to be wrong. Presumably the effort of arriving at a definition ought to clarify and support the self-evident ingredient. |
| 13476 | The failure of key assumptions in geometry, mereology and set theory throw doubt on the a priori [Hart,WD] |
| Full Idea: In the case of the parallels postulate, Euclid's fifth axiom (the whole is greater than the part), and comprehension, saying was believing for a while, but what was said was false. This should make a shrewd philosopher sceptical about a priori knowledge. | |
| From: William D. Hart (The Evolution of Logic [2010], 2) | |
| A reaction: Euclid's fifth is challenged by infinite numbers, and comprehension is challenged by Russell's paradox. I can't see a defender of the a priori being greatly worried about these cases. No one ever said we would be right - in doing arithmetic, for example. |
| 13475 | The Fregean concept of GREEN is a function assigning true to green things, and false to the rest [Hart,WD] |
| Full Idea: A Fregean concept is a function that assigns to each object a truth value. So instead of the colour green, the concept GREEN assigns truth to each green thing, but falsity to anything else. | |
| From: William D. Hart (The Evolution of Logic [2010], 2) | |
| A reaction: This would seem to immediately hit the renate/cordate problem, if there was a world in which all and only the green things happened to be square. How could Frege then distinguish the green from the square? Compare Idea 8245. |
| 14504 | The Kripke/Putnam approach to natural kind terms seems to give them excessive stability [Koslicki] |
| Full Idea: Theoretical terms such as 'mass', 'force', 'motion', 'species' and 'phlogiston' seem to indicate that the Kripke/Putnam approach to natural kind terms is committed to an excessive amount of stability in the meaning and reference of such expressions. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 8.6.2) | |
| A reaction: This sounds right to me. The notion of 'rigid' designation gives a nice framework for modal logic, but it doesn't seem to fit the shifting patterns of scientific thought. |
| 13285 | Natural kinds support inductive inferences, from previous samples to the next one [Koslicki] |
| Full Idea: Natural kinds are said to stand out from other classifications because they support legitimate inductive inferences ...as when we observe that past samples of copper conduct electricity and infer that the next sample will too. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 8.3.1) | |
| A reaction: A slightly more precise version of the Upanishad definition of natural kinds which I favour (Idea 8153). If you can't predict the next one from the previous one, it isn't a natural kind. You can't quite predict the next tiger from the previous one. |
| 13287 | Concepts for species are either intrinsic structure, or relations like breeding or ancestry [Koslicki] |
| Full Idea: Candidate species concepts can be intrinsic: morphological, physiological or genetic similarity; or relational: biology such as interbreeding and reproductive isolation, ecology, such as mate recognition in a niche, or phylogenetics (ancestor relations). | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 8.4.1) | |
| A reaction: She says the relational ones are more popular, but I gather they all hit problems. See John Dupré on the hopelessness of the whole task. |
| 13284 | Should vernacular classifications ever be counted as natural kind terms? [Koslicki] |
| Full Idea: It is controversial whether classificatory expressions from the vernacular should ever really be counted as genuine natural kind terms. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 8.2) | |
| A reaction: This is a similar confrontation between the folk and the scientific specialist as we find in folk psychology. There are good defences of folk psychology, and it looks plausible to defend the folk classifications as having priority. |
| 13286 | There are apparently no scientific laws concerning biological species [Koslicki] |
| Full Idea: It has been observed that there are apparently no scientific laws concerning biological species. | |
| From: Kathrin Koslicki (The Structure of Objects [2008], 8.4.1) | |
| A reaction: The central concept of biology I take to be a 'mechanism'. and I suspect that this view of science is actually applicable in physics and chemistry, with so-called 'laws' being a merely superficial description of what is going on. |