57 ideas
| 23367 | Even pointing a finger should only be done for a reason [Epictetus] |
| Full Idea: Philosophy says it is not right even to stretch out a finger without some reason. | |
| From: Epictetus (fragments/reports [c.57], 15) | |
| A reaction: The key point here is that philosophy concerns action, an idea on which Epictetus is very keen. He rather despise theory. This idea perfectly sums up the concept of the wholly rational life (which no rational person would actually want to live!). |
| 11832 | We learn a concept's relations by using it, without reducing it to anything [Wiggins] |
| Full Idea: We can achieve a lot by elucidations that put a concept to use without attempting to reduce it but, in using the concept, exhibit its connexions with other concepts that are established. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], Pr.3) | |
| A reaction: This seems to be the best line of defence for analytic philosophy, given the much-cited observation that no one has successful reduced any concept by pure analysis. |
| 5750 | Consistency is modal, saying propositions are consistent if they could be true together [Melia] |
| Full Idea: Consistency is a modal notion: a set of propositions is consistent iff all the members of the set could be true together. | |
| From: Joseph Melia (Modality [2003], Ch.6) | |
| A reaction: This shows why Kantian ethics, for example, needs a metaphysical underpinning. Maybe Kant should have believed in the reality of Leibnizian possible worlds? An account of reason requires an account of necessity and possibility. |
| 5737 | Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets [Melia] |
| Full Idea: First-order predicate language has four connectives, two quantifiers, variables, predicates, equality, names, and brackets. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: Look up the reference for the details! The spirit of logic is seen in this basic framework, and the main interest is in the ontological commitment of the items on the list. The list is either known a priori, or it is merely conventional. |
| 5744 | First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia] |
| Full Idea: First-order predicate calculus is an extensional logic, while quantified modal logic is intensional (which has grave problems of interpretation, according to Quine). | |
| From: Joseph Melia (Modality [2003], Ch.3) | |
| A reaction: The battle is over ontology. Quine wants the ontology to stick with the values of the variables (i.e. the items in the real world that are quantified over in the extension). The rival view arises from attempts to explain necessity and counterfactuals. |
| 11863 | (λx)[Man x] means 'the property x has iff x is a man'. [Wiggins] |
| Full Idea: The Lambda Abstraction Operator: We can write (λx)[Man x], which may be read as 'the property that any x has just if x is a man'. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.2) | |
| A reaction: This technical device seems to be a commonplace in modern metaphysical discussions. I'm assuming it can be used to discuss properties without venturing into second-order logic. Presumably we could call the property here 'humanity'. |
| 5740 | Second-order logic needs second-order variables and quantification into predicate position [Melia] |
| Full Idea: Permitting quantification into predicate position and adding second-order variables leads to second-order logic. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: Often expressed by saying that we now quantify over predicates and relations, rather than just objects. Depends on your metaphysical commitments. |
| 5741 | If every model that makes premises true also makes conclusion true, the argument is valid [Melia] |
| Full Idea: In first-order predicate calculus validity is defined thus: an argument is valid iff every model that makes the premises of the argument true also makes the conclusion of the argument true. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: See Melia Ch. 2 for an explanation of a 'model'. Traditional views of validity tend to say that if the premises are true the conclusion has to be true (necessarily), but this introduces the modal term 'necessarily', which is controversial. |
| 14746 | What exists can't depend on our conceptual scheme, and using all conceptual schemes is too liberal [Sider on Wiggins] |
| Full Idea: It would be incredible if what there is, rather than what we select for attention, depends on human activity and our conceptual scheme. One might expand to possible sortal concepts, rather than our language, but that amounts to four-dimensionalism. | |
| From: comment on David Wiggins (Sameness and Substance Renewed [2001]) by Theodore Sider - Four Dimensionalism 5.3 | |
| A reaction: [compression of a nice anti-Wiggins paragraph] He suggests that Wiggins is seeking an intermediate course (between narrow chauvinism about concepts, and excessive liberalism) in a discussion of natural kinds versus artifacts. |
| 5735 | Maybe names and predicates can capture any fact [Melia] |
| Full Idea: Some philosophers think that any fact can be captured in a language containing only names and predicates. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: The problem case Melia is discussing is modal facts, such as 'x is possible'. It is hard to see how 'possible' could be an ordinary predicate, but then McGinn claims that 'existence' is, and that there are some predicates with unusual characters. |
| 5736 | No sort of plain language or levels of logic can express modal facts properly [Melia] |
| Full Idea: Some philosophers say that modal facts cannot be expressed either by name/predicate language, or by first-order predicate calculus, or even by second-order logic. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: If 'possible' were a predicate, none of this paraphernalia would be needed. If possible worlds are accepted, then the quantifiers of first-order predicate calculus will do the job. If neither of these will do, there seems to be a problem. |
| 11900 | We can accept criteria of distinctness and persistence, without making the counterfactual claims [Mackie,P on Wiggins] |
| Full Idea: We might agree with Wiggins's theory of individuation, but reject his thesis that a thing's principle of individuation (of distinctness and persistence) must be preserved in all counterfactual situations. | |
| From: comment on David Wiggins (Sameness and Substance Renewed [2001]) by Penelope Mackie - How Things Might Have Been 8.7 | |
| A reaction: I'm not even convinced that initial individuation consists of falling under a sortal, and I prefer to discuss the powers of the thing, rather than counterfactual facts about behaviour. |
| 11870 | Activity individuates natural things, functions do artefacts, and intentions do artworks [Wiggins] |
| Full Idea: What a principle of activity does completely for a natural thing, and the function does imperfectly for an ordinary artefact, the artist's conception of his own making of the work must do for the painting. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.12) | |
| A reaction: This nicely sums up Wiggins on individuation, and he seems to effectively elide individuation with essence. I certainly feel uneasy that a work of art needs a quite separate account from other artefacts. Surely it is just that we are fussier about them? |
| 11866 | The idea of 'thisness' is better expressed with designation/predication and particular/universal [Wiggins] |
| Full Idea: It is hard to think of anything true and significant that could not be said using the idea of thisness not better said while respectiving the distinctions designation/predication and particular/universal. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.7) | |
| A reaction: Politis calls 'thisness' the 'ultimate subject of predication', so it is covered in logic by the name for an object. But we need to understand objects, and not just refer to them, and I'm not sure that 'universals' advance our understanding. |
| 11896 | A sortal essence is a thing's principle of individuation [Wiggins, by Mackie,P] |
| Full Idea: Wiggins bases sortal essentialism on the notion that a thing's principle of individuation is essential to it. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Penelope Mackie - How Things Might Have Been 7.1 | |
| A reaction: This idea has failed to make much impression on me. I seem to be the only person who doesn't understand the concept of 'individuation'. Please let me know exactly what it means. Type individuation is not individual individuation, I presume. |
| 15835 | Wiggins's sortal essentialism rests on a thing's principle of individuation [Wiggins, by Mackie,P] |
| Full Idea: Wiggins bases sortal essentialism on the notion that a thing's principle of individuation is essential to it. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Penelope Mackie - How Things Might Have Been 7.1 | |
| A reaction: My problem with this is that individuation is a human activity, not an intrinsic feature of the entities in the external world. Entities presumably have a 'unity', but I'm not sure about a 'principle' that does that job, though Aristotle is sympathetic. |
| 11841 | The evening star is the same planet but not the same star as the morning star, since it is not a star [Wiggins] |
| Full Idea: The evening star is the same planet but not the same star as the morning star. For Venus is not a star. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.3) | |
| A reaction: This is a nice objection to the idea that identity is entirely a matter of falling under the same sortal category. |
| 10679 | 'Sortalism' says parts only compose a whole if it falls under a sort or kind [Wiggins, by Hossack] |
| Full Idea: 'Sortalism' endorses the view that some things have parts, but denies that every collection of things composes something. Whenever there is a particular, there must be a sort or kind to which it belongs. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Keith Hossack - Plurals and Complexes 7 | |
| A reaction: What is the status of 'the first of its kind'? This seems to say that a token only has identity if it has type-identity. This sounds wildly wrong to me. I've made a 'thing' for you, but I haven't decided what it is yet. |
| 14363 | Identity a=b is only possible with some concept to give persistence and existence conditions [Wiggins, by Strawson,P] |
| Full Idea: Wiggins says an identity a=b stands no chance of being true unless there is some concept f under which a falls and under which b falls, which 'determines identity, persistence and existence conditions for members of its extension'. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Peter F. Strawson - Review of 'Sameness and Substance' p.604 | |
| A reaction: This is the first clear statement I have met of Wiggins's central idea, upon which his sortal essentialism is built. Strawson's exposition adds that each thing necessarily falls under the 'highest' appropriate sortal ('dog', rather than 'terrier'). |
| 14364 | A thing is necessarily its highest sortal kind, which entails an essential constitution [Wiggins, by Strawson,P] |
| Full Idea: In Wiggins's theory, necessity carries over from the kind to constitution. If Toby is necessarily a dog and 'dog' is a natural kind term, then Toby necessarily has the constitution of a dog, the features of which make up the real essence of being a dog. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Peter F. Strawson - Review of 'Sameness and Substance' p.605 | |
| A reaction: The essence will then presumably consist of all and only the characteristics which are shared by all dogs whatsoever. So how do you decide the borderline between wolf and dog? Why isn't a wolf a dog? |
| 11851 | Many predicates are purely generic, or pure determiners, rather than sortals [Wiggins] |
| Full Idea: There are countless predicates in English that have the appearance of sortal predicates but are purely generic (animal, machine, artefact), or are pure determinables for sortal determination (space-occupier, entity, substance). | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.6) | |
| A reaction: This is preparing the ground for a specification of a sortal which defines something essential as being the hallmark of identity. It is never quite clear to me whether Wiggins's case rests on a nominal or a real essence. |
| 11865 | The possibility of a property needs an essential sortal concept to conceive it [Wiggins] |
| Full Idea: A thing could have a property only if its having the property could be conceived, and that requires some sortal concept which adequately answers the Aristotelian question what the thing is. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.5) | |
| A reaction: [Algebra omitted!] The core idea of Wiggins's theory. It seems at first glance to be a revival of Aristotelian essentialism, but his view of that seems to merely involve falling into a category. He treats sortal concepts as Aristotle's 'primary being'. |
| 14744 | Objects can only coincide if they are of different kinds; trees can't coincide with other trees [Wiggins, by Sider] |
| Full Idea: Wiggins says that coincidence is possible only between objects of different kinds. Trees and cats coincide with aggregates of matter, but never trees with trees or cats with cats. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Theodore Sider - Four Dimensionalism 5.3 | |
| A reaction: At first glance this sounds quite plausible, but I think this commitment to the priority of kinds produces huge confusion, given that we only derive our notions of kinds from inductions derived from individuals. Language perpetuates old inductions. |
| 11852 | Is the Pope's crown one crown, if it is made of many crowns? [Wiggins] |
| Full Idea: The Pope's crown is made of crowns. There is no definite answer, when the Pope is wearing his crown, to the question 'how many crowns does he have on his head?' | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.7) | |
| A reaction: A very nice example, in which the identity of the item seems clear enough, until you try to apply a sortal to it. I can't get excited about it, though, because calling it one 'crown' creates uncertainty, but calling it the 'Pope's crown' doesn't. |
| 11875 | Boundaries are not crucial to mountains, so they are determinate without a determinate extent [Wiggins] |
| Full Idea: It can be perfectly determinate which mountain x is without x's extent's being determinate. A mountain is not, after all, something essentially demarcated by its extent or boundary. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 6.5) | |
| A reaction: This endorses something I have always wanted to assert ('a vague boundary is still a boundary'), but with the interesting addition that one might think about vagueness in terms of what is essential to a thing. Hm.... |
| 14749 | Identity is an atemporal relation, but composition is relative to times [Wiggins, by Sider] |
| Full Idea: Wiggins points out that identity is an atemporal relation whereas composition, like parthood, holds only relative to times. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Theodore Sider - Four Dimensionalism 5.3 | |
| A reaction: If David Cameron is identical to the Prime Minister, that doesn't seem to be atemporal. If x=7 in this problem, I can change x to something else in the next problem. x had better not be equal to 7 and to 9. |
| 11844 | If I destroy an item, I do not destroy each part of it [Wiggins] |
| Full Idea: If I repair or destroy an item, I do not repair or destroy each part of it (and since each part of a part is a part this would be difficult). | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.6) | |
| A reaction: This seems like a nice refutation of any attempt to claim that a thing is no more than the sum of its parts, but one could analyse the notion of 'destroy', and find it just meant introducing gaps between parts. |
| 11861 | We can forget about individual or particularized essences [Wiggins] |
| Full Idea: Let us be realistic, and forget about individual or particularized essences. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.2) | |
| A reaction: This is the rather weird position you reach if you follow Wiggins's 'modest' essentialism, deriving from a thing merely falling under a sortal, or into a category. What is a natural kind, if its members don't each have a shared essence? |
| 11871 | Essences are not explanations, but individuations [Wiggins] |
| Full Idea: Essences of natural things are not fancified vacuities parading themselves ...as the ultimate explanation of everything that happens in the world. They are natures whose possession is a precondition of their owners being divided from the rest of reality. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 5.2) | |
| A reaction: Thus Wiggins rejects the explanation account of essence, with an assertion of his own (highly implausible) view that essence is about individuation rather than about behaviour. Individuation strikes me as an entirely human activity, and not 'real'. |
| 11879 | Essentialism is best represented as a predicate-modifier: □(a exists → a is F) [Wiggins, by Mackie,P] |
| Full Idea: Wiggins's proposal of a predicate-modifier account is the best formal representation of essential statements. ...This simple version is perfectly adequate to represent the claim that a is essentially-F: □(a exists → a is F). | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001], Ch.4) by Penelope Mackie - How Things Might Have Been 1.2 | |
| A reaction: I suppose that is right. Having an essence is a feature of an entity, but it has to boil done to characteristics that define the entity, and which it must presumably always have. Could an entity ever lack its essence? |
| 11835 | The nominal essence is the idea behind a name used for sorting [Wiggins] |
| Full Idea: Things being ranked under Names into sorts only as they agree with certain abstract ideas, to which we have annexed the Names, the essence of each sort comes to nothing but that abstract idea which the sortal name stands for. This is the nominal Essence. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], III.iii.15) | |
| A reaction: He contrasts 'nominal essence' with 'real essence'. A key passage for David Wiggins. One shouldn't put too much emphasis on nominal essence, since it means that someone referred to as 'that idiot over there' (you, perhaps) is necessarily an idiot. |
| 11876 | It is easier to go from horses to horse-stages than from horse-stages to horses [Wiggins] |
| Full Idea: If horse-stages made sense at all, it would be easier to go from horses to horse-stages than to go from horse-stages to horses. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 6.9) | |
| A reaction: A nice remark, analogous to 'it is easier to break a vase than to mend it'. Going from horse-stages to horses is the classic difficulty for 'bundle theories' (of objects, or persons): what is it that unites the bundle? |
| 11858 | The question is not what gets the title 'Theseus' Ship', but what is identical with the original [Wiggins] |
| Full Idea: Let us remember that the title in question is not the title to the sobriquet 'Theseus' Ship'; it is the title to identity with Theseus' ship, a particular ship originating from the eighth century B.C. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 3.4) | |
| A reaction: There is an assumption here that identity is defined by origin. What is the origin of the identity of those huge football clubs that began under the name of some village team in 1875? What is the origin of 'England' as a single entity? |
| 11843 | Identity over a time and at a time aren't different concepts [Wiggins] |
| Full Idea: People often speak of identity over time and distinguish it from identity at a time. But identity is just identity. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.3) | |
| A reaction: I myself am guilty of such usage, but it doesn't imply a commitment to a multivocal concept. The epistemological issues (of explaining what it is now, and simply reidentifying it later) seem profoundly different. Hume only admits identity over time. |
| 11864 | Hesperus=Hesperus, and Phosphorus=Hesperus, so necessarily Phosphorus=Hesperus [Wiggins] |
| Full Idea: The simple proof (from Ruth Barcan Marcus) is: Hesperus is necessarily Hesperus, so if Phosphorus is Hesperus, then Phosphorus is necessarily Hesperus. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.3) | |
| A reaction: This is the famous idea which she noticed well before Kripke. The point is that the simple logic of the case bestows a necessity on the identity. We shouldn't be confused by the a posteriori and contingent nature of the discovery. |
| 11831 | The formal properties of identity are reflexivity and Leibniz's Law [Wiggins] |
| Full Idea: The formal properties of identity are the reflexivity of identity, and Leibniz's Law (if x is the same as y, then whatever is true of one is true of the other). | |
| From: David Wiggins (Sameness and Substance Renewed [2001], Pr.2) | |
| A reaction: Presumably transitivity will also apply, and, indeed, symmetry. He seems to mean something like the 'axiomatic formal properties'. |
| 14362 | Relative Identity is incompatible with the Indiscernibility of Identicals [Wiggins, by Strawson,P] |
| Full Idea: Wiggins argues that Geach's Relative Identity is incompatible with the formal properties of identity, which include, besides transitivity, symmetry and reflexivity, the complete community of properties defined by the Indiscernibility of Identicals. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Peter F. Strawson - Review of 'Sameness and Substance' p.603 | |
| A reaction: The tricky part is that Wiggins then goes on to say that identity depends on sortals, which sounds very close to the Geach view. I find disentangling them tricky. See Idea 14363 for a helpful comment from Strawson. |
| 11838 | Relativity of Identity makes identity entirely depend on a category [Wiggins] |
| Full Idea: The thesis of Relativity of Identity (which I steadfastly oppose) ..suggests that it makes all the difference to keeping track of continuants through space and time which concept one subsumes something under. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 1.1) | |
| A reaction: [Geach I take to be the villain of this idea] The point is that identity is entirely relative to the sortal concept, where Wiggins wants to make identity a combination of the object itself and our concept of it (I think). |
| 11847 | To identify two items, we must have a common sort for them [Wiggins] |
| Full Idea: As a necessary condition of the truth of an identity claim, some common sort f will have to be found to which they each belong. That is the point at which the primary question of identity can come into focus. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.2) | |
| A reaction: This is the plainest English expression I can find of Wiggins's main thesis. He maintains this thesis, while adamantly denying the idea that identity consists entirely of falling under a concept. |
| 5746 | The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia] |
| Full Idea: If the Identity of Indiscernibles is referring to qualitative properties, such as 'being red' or 'having mass', it is contentious; if it is referring to non-qualitative properties, such as 'member of set s' or 'brother of a', it is true but trivial. | |
| From: Joseph Melia (Modality [2003], Ch.3 n 11) | |
| A reaction: I would say 'false' rather than 'contentious'. No one has ever offered a way of distinguishing two electrons, but that doesn't mean there is just one (very busy) electron. The problem is that 'indiscernible' is only an epistemological concept. |
| 11839 | Do both 'same f as' and '=' support Leibniz's Law? [Wiggins] |
| Full Idea: Is Leibniz's Law as true for 'is the same as' as it is for '='? | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 1.2) | |
| A reaction: [By Leibniz's Law he means if they are the same, they support the same truths] |
| 11845 | Substitutivity, and hence most reasoning, needs Leibniz's Law [Wiggins] |
| Full Idea: Leibniz's Law underwrites the substitutivity of identity and this is a principle not long dispensable in any form of reasoning. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.7) | |
| A reaction: Thus the modern fashion of deriving our metaphysics from our logic. Presumably we can derive it from our epistemology too, or even from our intuitions, if we thought they were good enough as evidence. |
| 5738 | We may be sure that P is necessary, but is it necessarily necessary? [Melia] |
| Full Idea: We may have fairly firm beliefs as to whether or not P is necessary, but many of us find ourselves at a complete loss when wondering whether or not P is necessarily necessary. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: I think it is questions like this which are pushing philosophy back towards some sort of rationalism. See Idea 3651, for example. A regress of necessities would be mad, so necessity must be taken as self-evident (in itself, though maybe not to us). |
| 5732 | 'De re' modality is about things themselves, 'de dicto' modality is about propositions [Melia] |
| Full Idea: In cases of 'de re' modality, it is a particular thing that has the property essentially or accidentally; where the modality attaches to the proposition, it is 'de dicto' - it is the whole truth that all bachelors are unmarried that is necessary. | |
| From: Joseph Melia (Modality [2003], Ch.1) | |
| A reaction: This seems to me one of the most important distinctions in metaphysics (as practised by analytical philosophers, who like distinctions). The first type leads off into the ontology, the second type veers towards epistemology. |
| 5739 | Sometimes we want to specify in what ways a thing is possible [Melia] |
| Full Idea: Sometimes we want to count the ways in which something is possible, or say that there are many ways in which a certain thing is possible. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: This is a basic fact about talk of 'possibility'. It is not an all-or-nothing property of a situation. There can be 'faint' possibilities of things. The proximity of some possible worlds, especially those sharing our natural laws, is one answer. |
| 5734 | Possible worlds make it possible to define necessity and counterfactuals without new primitives [Melia] |
| Full Idea: In modal logic the concepts of necessity and counterfactuals are not interdefinable, so the language needs two primitives to represent them, but with the machinery of possible worlds they are defined by what is the case in all worlds, or close worlds. | |
| From: Joseph Melia (Modality [2003], Ch.1) | |
| A reaction: If your motivation is to reduce ontology to the barest of minimums (which it was for David Lewis) then it is paradoxical that the existence of possible worlds may be the way to achieve it. I doubt, though, whether a commitment to their reality is needed. |
| 5742 | In possible worlds semantics the modal operators are treated as quantifiers [Melia] |
| Full Idea: The central idea in possible worlds semantics is that the modal operators are treated as quantifiers. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: It seems an essential requirement of metaphysics that an account be given of possibility and necessity, and it is also a good dream to keep the ontology simple. Commitment to possible worlds is the bizarre outcome of this dream. |
| 5743 | If possible worlds semantics is not realist about possible worlds, logic becomes merely formal [Melia] |
| Full Idea: It has proved difficult to justify possible worlds semantics without accepting possible worlds. Without a secure metaphysical underpinning, the results in logic are in danger of having nothing more than a formal significance. | |
| From: Joseph Melia (Modality [2003], Ch.2) | |
| A reaction: This makes nicely clear why Lewis's controversial modal realism has to be taken seriously. It appears that the key problem is truth, because that is needed to define validity, but you can't have truth without some sort of metaphysics. |
| 5749 | Possible worlds could be real as mathematics, propositions, properties, or like books [Melia] |
| Full Idea: One can be a realist about possible worlds without adopting Lewis's extreme views; they might be abstract or mathematical entities; they might be sets of propositions or maximal uninstantiated properties; they might be like books or pictures. | |
| From: Joseph Melia (Modality [2003], Ch.6) | |
| A reaction: My intuition is that once you go down the road of realism about possible worlds, Lewis's full concrete realism looks at least as attractive as any of these options. You can discuss the 'average man' in an economic theory without realism. |
| 11869 | Possible worlds rest on the objects about which we have suppositions [Wiggins] |
| Full Idea: Worlds are the shadows of our suppositions and they take on their identity from these. Suppositions take on their identity from (inter alia) the objects they relate to. If they sever themselves from these objects, then they collapse. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.11) | |
| A reaction: Sounds good. My picture is of possibilities which are suggested by objecfs in the actual world, with extreme possibilities being at fifth-remove from actuality. Any worlds that go beyond natural possibility are just there for fun. |
| 5751 | The truth of propositions at possible worlds are implied by the world, just as in books [Melia] |
| Full Idea: Propositions are true at possible worlds in much the same way as they are true at books: by being implied by the book. | |
| From: Joseph Melia (Modality [2003], Ch.7) | |
| A reaction: An intriguing way to introduce the view that possible worlds should be seen as like books. The truth-makers of propositions about the actual world are items in it, but the truth-makers in novels (say) are the conditions of the whole work as united. |
| 11850 | Not every story corresponds to a possible world [Wiggins] |
| Full Idea: It is perfectly notorious that not every story corresponds to a possible world. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.4) | |
| A reaction: Thus a fantasy castle might be decorated with 'beautiful circular squares', or be threatened by a lump of enriched uranium twenty feet in diameter. Wiggins is replying to the claim that a possible world represents a 'story'. |
| 11848 | Asking 'what is it?' nicely points us to the persistence of a continuing entity [Wiggins] |
| Full Idea: The special effectiveness of the 'what is it?' question is that, in the case of continuants, it refers us back to our constantly exercised idea of the persistence and life-span of an entity. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.2) | |
| A reaction: Compare 'this is a human' with 'this is a member of a family noted for its longevity'. We can't simply answer 'what is it?' by tossing it into the nearest category. I say we need an individual essence for explanation, not just a sortal. |
| 11859 | The mind conceptualizes objects; yet objects impinge upon the mind [Wiggins] |
| Full Idea: The mind conceptualizes objects; yet objects impinge upon the mind. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 3.6) | |
| A reaction: I like this piece of simple common sense. I personally don't think you can reach first base in a sensible discussion if you don't face up to both sides of this idea (especially the second half, which many philosophers, especially of language, neglect). |
| 11836 | We can use 'concept' for the reference, and 'conception' for sense [Wiggins] |
| Full Idea: We can use the Fregean 'concept' on the level of reference and naming, and prefer the word 'conception' for the Kantian idea of the sense, or the information needed to understand the concept. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], Pr.5) | |
| A reaction: This is a nice suggestion, and at first blush I think it should be adopted. Sometimes philosophers regret adopting a terminology several hundred years after it has been agreed. |
| 5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
| Full Idea: Many philosophers now concede that it is rational to accept a proposition not because we can directly verify it but because it is supported by considerations of simplicity, theoretical utility, explanatory power and/or intuitive plausibility. | |
| From: Joseph Melia (Modality [2003], Ch.5) | |
| A reaction: This suggests how the weakness of logical positivism may have led us to the concept of epistemic virtues (such as those listed), which are, of course, largely a matter of community consensus, just as the moral virtues are. |
| 11860 | Lawlike propensities are enough to individuate natural kinds [Wiggins] |
| Full Idea: For all the purposes of identity and individuation of things that belong to natural kinds..., it is enough to have regard for the lawlike propensities of members of the kind. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.1) | |
| A reaction: This may have got things in reverse, since it is hard to see how you could pick out any laws if you didn't assume the existence of natural kinds which were causing the regularities in the behaviour. |