34 ideas
| 18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
| Full Idea: Three periods can be distinguished in philosophical logic: the syntactic stage, from Russell's definite descriptions to the 1950s, the dominance of possible world semantics from the 50s to 80s, and a current widening of the subject. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 1) | |
| A reaction: [compressed] I've read elsewhere that the arrival of Tarski's account of truth in 1933, taking things beyond the syntactic, was also a landmark. |
| 18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
| Full Idea: Logical formalization forces the investigator to make the central philosophical concepts precise. It can also show how some philosophical concepts and objects can be defined in terms of others. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: This is the main rationale of the highly formal and mathematical approach to such things. The downside is when you impose 'precision' on language that was never intended to be precise. |
| 18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
| Full Idea: A (logical) model is a set with functions and relations defined on it that specify the denotation of the non-logical vocabulary. A series of recursive clauses explicate how truth values of complex sentences are compositionally determined from the parts. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: See the ideas on 'Functions in logic' and 'Relations in logic' (in the alphabetical list) to expand this important idea. |
| 18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
| Full Idea: If there is indeed no property of existence that is expressed by the word 'exist', then it makes no sense to ask for its essence. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: As far as I can tell, this was exactly Aristotle's conclusion, so he skirted round the question of 'being qua being', and focused on the nature of objects instead. Grand continental talk of 'Being' doesn't sound very interesting. |
| 18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
| Full Idea: A Tarskian model can in a sense be seen as a model of a possible state of affairs. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: I include this remark to show how possible worlds semantics built on the arrival of model theory. |
| 18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
| Full Idea: The notion of a possible worlds model was extended (resulting in the concept of a 'spheres model') in order to obtain a satisfactory logical treatment of counterfactual conditional sentences. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Thus we add 'centred' worlds, and an 'actual' world, to the loose original model. It is important to remember when we discuss 'close' worlds that we are then committed to these presuppositions. |
| 18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
| Full Idea: The idea of 'impossible worlds' was introduced into epistemic logic. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Nathan Salmon seems interested in their role in metaphysics (presumably in relation to Meinongian impossible objects, like circular squares, which must necessarily be circular). |
| 18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
| Full Idea: Each possible worlds model contains a set of possible worlds. For this reason, possible worlds semantics is often charged with smuggling in heavy metaphysical commitments. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: To a beginner it looks very odd that you should try to explain possibility by constructing a model of it in terms of 'possible' worlds. |
| 18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |
| Full Idea: When the possible worlds semantics were further extended to model notions of knowledge and of moral obligation, the application was beginning to look distinctly forced and artificial. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 5) | |
| A reaction: They accept lots of successes in modelling necessity and time. |
| 17979 | Research shows perceptual discrimination is sharper at category boundaries [Murphy] |
| Full Idea: Goldstone's research has shown how learning concepts can change perceptual units. For example, perceptual discrimination is heightened along category boundaries. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) | |
| A reaction: [Goldstone 1994, 2000] This is just the sort of research which throws a spanner into the simplistic a priori thinking of many philosophers. |
| 1556 | By nature people are close to one another, but culture drives them apart [Hippias] |
| Full Idea: I regard you all as relatives - by nature, not by convention. By nature like is akin to like, but convention is a tyrant over humankind and often constrains people to act contrary to nature. | |
| From: Hippias (fragments/reports [c.430 BCE]), quoted by Plato - Protagoras 337c8 |
| 18690 | Induction is said to just compare properties of categories, but the type of property also matters [Murphy] |
| Full Idea: Most theories of induction claim that it should depend primarily on the similarity of the categories involved, but then the type of property should not matter, yet research shows that it does. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 6) | |
| A reaction: I take this to be good empirical support for Gilbert Harman's view that induction is really inference to the best explanation. The thought (which strikes me as obviously correct) is that we bring nested domains of knowledge to bear in induction. |
| 17980 | The main theories of concepts are exemplar, prototype and knowledge [Murphy] |
| Full Idea: The three main theories of concepts under consideration are the exemplar, the prototype and the knowledge approaches. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) |
| 17973 | The theoretical and practical definitions for the classical view are very hard to find [Murphy] |
| Full Idea: It has been extremely difficult to find definitions for most natural categories, and even harder to find definitions that are plausible psychological representations that people of all ages would be likely to use. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 2) |
| 17969 | The classical definitional approach cannot distinguish typical and atypical category members [Murphy] |
| Full Idea: The early psychological approaches to concepts took a definitional approach. ...but this view does not have any way of distinguishing typical and atypical category members (...as when a trout is a typical fish and an eel an atypical one). | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 2) | |
| A reaction: [pp. 12 and 22] Eleanor Rosch in the 1970s is said to have largely killed off the classical view. |
| 17970 | Classical concepts follow classical logic, but concepts in real life don't work that way [Murphy] |
| Full Idea: The classical view of concepts has been tied to traditional logic. 'Fido is a dog and a pet' is true if it has the necessary and sufficient conditions for both, ...but there is empirical evidence that people do not follow that rule. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 2) | |
| A reaction: Examples given are classifying chess as a sport and/or game, and classifying a tree house (which is agreed to be both a building and not a building!). |
| 17971 | Classical concepts are transitive hierarchies, but actual categories may be intransitive [Murphy] |
| Full Idea: The classical view of concepts explains hierarchical order, where categories form nested sets. But research shows that categories are often not transitive. Research shows that a seat is furniture, and a car seat is a seat, but it is not furniture. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 2) | |
| A reaction: [compressed] Murphy adds that the nesting of definitions is classically used to match the nesting of hierarchies. This is a nice example of the neatness of the analytic philosopher breaking down when it meets the mess of the world. |
| 17972 | The classical core is meant to be the real concept, but actually seems unimportant [Murphy] |
| Full Idea: A problem with the revised classical view is that the concept core does not seem to be an important part of the concept, despite its name and theoretical intention as representing the 'real' concept. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 2) | |
| A reaction: Apparently most researchers feel they can explain their results without reference to any core. Not so fast, I would say (being an essentialist). Maybe people acknowledge an implicit core without knowing what it is. See Susan Gelman. |
| 17975 | There is no 'ideal' bird or dog, and prototypes give no information about variability [Murphy] |
| Full Idea: Is there really an 'ideal bird' that could represent all birds? ...Furthermore a single prototype would give no information about the variability of a category. ...Compare the incredible variety of dogs to the much smaller diversity of cats. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 3) | |
| A reaction: The point about variability is particularly noteworthy. You only grasp the concept of 'furniture' when you understand its range, as well as its typical examples. What structure is needed in a concept to achieve this? |
| 17976 | Prototypes are unified representations of the entire category (rather than of members) [Murphy] |
| Full Idea: In the prototype view the entire category is represented by a unified representation rather than separate representations for each member, or for different classes of members. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 3) | |
| A reaction: This is the improved prototype view, as opposed to the implausible idea that there is one ideal exemplar. The new theory still have the problem of how to represent diversity within the category, while somehow remaining 'unified'. |
| 18691 | The prototype theory uses observed features, but can't include their construction [Murphy] |
| Full Idea: Nothing in the prototype model says the shape of an animal is more important than its location in identifying its kind. The theory does not provide a way the features can be constructed, rather than just observed. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 6) | |
| A reaction: This makes some kind of mental modelling central to thought, and not just a bonus once you have empirically acquired the concepts. We bring our full range of experience to bear on even the most instantaneous observations. |
| 17983 | The prototype theory handles hierarchical categories and combinations of concepts well [Murphy] |
| Full Idea: The prototype view has no trouble with either hierarchical structure or explaining categories. ...Meaning and conceptual combination provide strong evidence for prototypes. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) | |
| A reaction: Prototypes are not vague, making clearer classification possible. A 'mountain lion' is clear, because its components are clear. |
| 17985 | Prototypes theory of concepts is best, as a full description with weighted typical features [Murphy] |
| Full Idea: Our theory of concepts must be primarily prototype-based. That is, it must be a description of an entire concept, with its typical features (presumably weighted by their importance). | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) | |
| A reaction: This is to be distinguished from the discredited 'classical' view of concepts, that the concept consists of its definition. I take Aristotle's account of definition to be closer to a prototype description than to a dictionary definition. |
| 17986 | Learning concepts is forming prototypes with a knowledge structure [Murphy] |
| Full Idea: My proposal is that people attempt to form prototypes as part of a larger knowledge structure when they learn concepts. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) | |
| A reaction: This combines theory theory (knowledge) with the prototype view, and sounds rather persuasive. The formation of prototypes fits with the explanatory account of essentialism I am defending. He later calls prototype formation 'abstraction' (494). |
| 17974 | The most popular theories of concepts are based on prototypes or exemplars [Murphy] |
| Full Idea: The most popular theories of concepts are based on prototype or exemplar theories that are strongly unclassical. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 2) |
| 17977 | The exemplar view of concepts says 'dogs' is the set of dogs I remember [Murphy] |
| Full Idea: In the exemplar view of concepts, the idea that people have a representation that somehow encompasses an entire concept is rejected. ...Instead a person's concept of dogs is the set of dogs that the person remembers. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 3) | |
| A reaction: [The theory was introduced by Medin and Schaffer 1978] I think I have finally met a plausible theory of concepts. When I think 'dog' I conjure up a fuzz of dogs that exhibit the range I have encountered (e.g. tiny to very big). Individuals come first! |
| 17982 | Exemplar theory struggles with hierarchical classification and with induction [Murphy] |
| Full Idea: The exemplar view has trouble with hierarchical classification and with induction in adults. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) | |
| A reaction: To me these both strongly support essentialism - that you form the concept 'dog' from seeing some dogs, but you then extrapolate to large categories and general truths about dogs, on the assumption of the natures of the dogs you have seen. |
| 17981 | Children using knowing and essentialist categories doesn't fit the exemplar view [Murphy] |
| Full Idea: The findings showing that children use knowledge and may be essentialist about category membership do not comport well with the exemplar view. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) | |
| A reaction: Tricky, because Gelman persuaded me of the essentialism, but the exemplar view of concepts looks the most promising. Clearly they must be forced to coexist.... |
| 17984 | Conceptual combination must be compositional, and can't be built up from exemplars [Murphy] |
| Full Idea: The exemplar accounts of conceptual combination are demonstrably wrong, because the meaning of a phrase has to be composed from the meaning of its parts (plus broader knowledge), and it cannot be composed as a function of exemplars. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) | |
| A reaction: This sounds quite persuasive, and I begin to see that my favoured essentialism fits the prototype view of concepts best, though this mustn't be interpreted too crudely. We change our prototypes with experience. 'Bird' is a tricky case. |
| 17987 | The concept of birds from exemplars must also be used in inductions about birds [Murphy] |
| Full Idea: We don't have one concept of birds formed by learning from exemplars, and another concept of birds that is used in induction. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13) | |
| A reaction: In other words exemplar concepts break down when we generalise using the concept. The exemplars must be unified, to be usable in thought and language. |
| 17978 | We do not learn concepts in isolation, but as an integrated part of broader knowledge [Murphy] |
| Full Idea: The knowledge approach argues that concepts are part of our general knowledge about the world. We do not learn concepts in isolation, ...but as part of our overall understanding of the world. Animal concepts are integrated with biology, behaviour etc. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 3) | |
| A reaction: This is one of the leading theories of concepts among psychologists. It seems to be an aspect of the true theory, but it needs underpinning with some account of isolated individual concepts. This is also known as the 'theory theory'. |
| 18687 | Concepts with familiar contents are easier to learn [Murphy] |
| Full Idea: A concept's content influences how easy it is to learn. If the concept is grossly incompatible with what people know prior to the experiment, it will be difficult to acquire. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 6) | |
| A reaction: This is a preliminary fact which leads towards the 'knowledge' theory of concepts (aka 'theory theory'). The point being that the knowledge involved is integral to the concept. Fits my preferred mental files approach. |
| 18688 | Some knowledge is involved in instant use of categories, other knowledge in explanations [Murphy] |
| Full Idea: Some kinds of knowledge are probably directly incorporated into the category representation and used in normal, fast decisions about objects. Other kinds of knowledge, however, may come into play only when it has been solicited. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 6) | |
| A reaction: This is a summary of empirical research, but seems to fit our normal experience. If you see a hawk, you have some instant understanding, but if you ask what the hawk is doing here, you draw more widely. |
| 18689 | People categorise things consistent with their knowledge, even rejecting some good evidence [Murphy] |
| Full Idea: People tend to positively categorise items that are consistent with their knowledge and to exclude items that are inconsistent, sometimes even overruling purely empirical sources of information. | |
| From: Gregory L. Murphy (The Big Book of Concepts [2004], Ch. 6) | |
| A reaction: The main rival to 'theory theory' is the purely empirical account of how concepts are acquired. This idea reports empirical research in favour of the theory theory (or 'knowledge') approach. |