47 ideas
| 13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
| Full Idea: Archimedes gave a sort of definition of 'straight line' when he said it is the shortest line between two points. | |
| From: report of Archimedes (fragments/reports [c.240 BCE]) by Gottfried Leibniz - New Essays on Human Understanding 4.13 | |
| A reaction: Commentators observe that this reduces the purity of the original Euclidean axioms, because it involves distance and measurement, which are absent from the purest geometry. |
| 6346 | The main epistemological theories are foundationalist, coherence, probabilistic and reliabilist [Pollock/Cruz] |
| Full Idea: The most familiar epistemological theories are foundation theories, coherence theories, probabilistic theories, and reliabilist theories. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], Pref) | |
| A reaction: A helpful list. Reliabilism is now the dominant externalist theory. Probability theories will centre on Bayes' Theorem (Idea 2798). The authors want an internalist theory that includes perceptions as well as beliefs. I currently favour coherence. |
| 6351 | Most people now agree that our reasoning proceeds defeasibly, rather than deductively [Pollock/Cruz] |
| Full Idea: One of the most important modern advances in epistemology was the recognition of defeasible reasons; it is now generally acknowledged that most of our reasoning proceeds defeasibly rather than deductively. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.2) | |
| A reaction: I agree totally. This is why fallibilism is clearly a correct position in epistemology (e.g. Ideas 2736 and 2755). Deduction is not the only grounds given for certainty - there are rationalist foundations (Descartes) and empiricist foundations (Moore). |
| 6374 | To believe maximum truths, believe everything; to have infallible beliefs, believe nothing [Pollock/Cruz] |
| Full Idea: If we want an agent to believe as many truths as possible, this could be achieved by simply believing everything; if we want an agent to have only true beliefs, this could be achieved by believing nothing. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §6.6) | |
| A reaction: I like this. It highlights the pragmatic need for a middle road, in which a core set of beliefs are going to be approved of as 'knowledge', so that we can get on with life. This has to be a social matter, and needs flexibility of Fallibilism. |
| 6355 | Direct realism says justification is partly a function of pure perceptual states, not of beliefs [Pollock/Cruz] |
| Full Idea: We defend a version of direct realism, saying that justification must be partly a function of perceptual states themselves, and not just a function of our beliefs about perceptual states. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.5.3) | |
| A reaction: Judgement suggests that perceptual states give good justification about primary qualities (like mass or shape), but not of secondary qualities (like smell or colour). Perceptions can be downright misleading. |
| 6359 | Phenomenalism offered conclusive perceptual knowledge, but conclusive reasons no longer seem essential [Pollock/Cruz] |
| Full Idea: Phenomenalism offered the prospect of explaining perceptual knowledge within a framework that recognised only conclusive reasons; once it is acknowledged that at least induction uses nonconclusive reasons, it is no longer needed. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.3.3.2) | |
| A reaction: I'm not sure that that is the only motivation for phenomenalism, which seemed to be attempting to get as close to 'reality' as intellectual honesty would allow. I certainly favour the modern relaxed attitude to knowledge, which needn't be 'conclusive'. |
| 6366 | Perception causes beliefs in us, without inference or justification [Pollock/Cruz] |
| Full Idea: Perception is a causal process that inputs beliefs into our doxastic system without their being inferred from or justified on the basis of other beliefs we already have. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.2.3) | |
| A reaction: This topic is much discussed (e.g. by MacDowell). I don't see how something is going to qualify as a 'belief' if it doesn't involve concepts and propositions. The point that we are caused to have many of our beliefs (rather than judging) seems right. |
| 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. |
| 6362 | Sense evidence is not beliefs, because they are about objective properties, not about appearances [Pollock/Cruz] |
| Full Idea: We think it is a mistake to suppose that the evidence of our senses comes to us in the form of beliefs; in perception, the beliefs we form are almost invariably about the objective properties of physical objects - not about how they appear to us. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.5.5) | |
| A reaction: The tricky word here is 'evidence'. At what point in the process of perception does something begin to count as evidence? It must at least involve concepts (and maybe even propositions) if it is going to be thought about in that way. |
| 6371 | Bayesian epistemology is Bayes' Theorem plus the 'simple rule' (believe P if it is probable) [Pollock/Cruz] |
| Full Idea: Bayesian epistemology is based upon the 'simple rule' (believe P if it is sufficiently probable) and Bayes' Theorem. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §4.3.1) | |
| A reaction: For Bayes' Theorem, see Idea 2798. There is the question of whether the proposition is subjectively or objectively probable (I believe in ghosts, so any shadow is probably a ghost). There is also the problem of objective evidence for the calculation. |
| 6373 | Internalism says if anything external varies, the justifiability of the belief does not vary [Pollock/Cruz] |
| Full Idea: Internalist theories make justifiability of a belief a function of the internal states of the believer, in the sense that if we vary anything but his internal states the justifiability of the belief does not vary. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §5.4.3) | |
| A reaction: This seems to be a nice clear definition of internalism (and, by implication, externalism). It favours externalism. I know my car is in the car park; someone takes it for a joyride, then replaces it; my good justification seems thereby weakened. |
| 6353 | People rarely have any basic beliefs, and never enough for good foundations [Pollock/Cruz] |
| Full Idea: We argue that all foundations theories are false, for the simple reason that people rarely have any epistemological basic beliefs, and never have enough to provide a foundation for the rest of our knowledge. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.5.3) | |
| A reaction: Once surprising things start to happen in a film, we rapidly jettison our normal basic beliefs, to be ready for surprises. However, it seems to me that quite a lot of beliefs are hard-wired into us, or inescapably arise from the use of our senses. |
| 6361 | Foundationalism requires self-justification, not incorrigibility [Pollock/Cruz] |
| Full Idea: What foundationalism requires is self-justification, which is weaker than incorrigibility. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.5.3) | |
| A reaction: The writers oppose foundationalism, but this remark obviously helps the theory. Bonjour votes for a fallible rationalist foundationalism, and an fallible empiricist version seems plausible (because we must check for hallucinations etc.). |
| 6357 | Reason cannot be an ultimate foundation, because rational justification requires prior beliefs [Pollock/Cruz] |
| Full Idea: Reasoning, it seems, can only justify us in holding a belief if we are already justified in holding the beliefs from which we reason, so reasoning cannot provide an ultimate source of justification. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.1) | |
| A reaction: This sounds slick and conclusive, but it isn't. If we accept that some truths might be 'self-evident' to reason, they could stand independently. And a large body of rational beliefs might be mutually self-supporting, as in the coherence theory of truth. |
| 6363 | Foundationalism is wrong, because either all beliefs are prima facie justified, or none are [Pollock/Cruz] |
| Full Idea: Either no belief is prima facie justified or all beliefs are prima facie justified; …we regard this as a decisive refutation of foundationalism. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.5.5) | |
| A reaction: The full text must he examined, but it is not at all clear to me how my belief that quantum theory is correct could be even remotely as prima facie justified as my belief that this is my hand. I don't think basic beliefs need be sharply divided off. |
| 6365 | Negative coherence theories do not require reasons, so have no regress problem [Pollock/Cruz] |
| Full Idea: The regress argument has no apparent strength against negative coherence theories, because they do not require reasons for beliefs. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.2.3) | |
| A reaction: A nice point. Such theories endorse Neurath's picture (Idea 6348). On the whole philosophers like positive support for their beliefs, so the rather passive picture of accepting everything unless it is undermined is not appealing. A fall-back position. |
| 6354 | Coherence theories fail, because they can't accommodate perception as the basis of knowledge [Pollock/Cruz] |
| Full Idea: All coherence theories fail, because they are unable to accommodate perception as the basic source of our knowledge of the world. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.5.3) | |
| A reaction: An interesting claim, which the authors attempt to justify. They say it is direct realism, because the perceptions justify, without any intervening beliefs. My immediate thought is that they might justify knowledge of primary qualities, but not secondary. |
| 6367 | Coherence theories isolate justification from the world [Pollock/Cruz] |
| Full Idea: The Isolation Argument objects that coherence theories cut justification off from the world. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.2.4) | |
| A reaction: I don't see this as a strong objection. Justification can be in the way beliefs cohere together, but the beliefs themselves consist of holding propositions to be true, and truth asserts a connection to the world (I say). |
| 6370 | Externalism comes as 'probabilism' (probability of truth) and 'reliabilism' (probability of good cognitive process) [Pollock/Cruz] |
| Full Idea: There are two major kinds of externalist theory in the literature - probabilism (which expresses justification in terms of probability of the belief being true), and reliabilism (which refers to the probability of the cognitive processes being right). | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §4.1) | |
| A reaction: A useful clarification. Reliabilism has an obvious problem, that a process can be reliable, but only luckily correct on this occasion (a clock which has, unusually, stopped). A ghost is more probably there if I believe in ghosts. |
| 6358 | One belief may cause another, without being the basis for the second belief [Pollock/Cruz] |
| Full Idea: If I fall flat on my back running to a class, my belief that I was late for class may cause me to have the belief that there are birds in the trees, but I do not believe the latter on the basis of the former. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.3.1) | |
| A reaction: A nice example, which fairly conclusively demolishes any causal theory of justification. My example is believing correctly that the phone ring is from mother, because she said she would call. Maybe causation is needed somewhere in the right theory. |
| 6364 | We can't start our beliefs from scratch, because we wouldn't know where to start [Pollock/Cruz] |
| Full Idea: We cannot forsake all of our beliefs and start over again, because then we could not know how to start. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §3.1) | |
| A reaction: A point with which it is hard to disagree, but even Descartes agreed with it (Idea 3604). Presumably all your beliefs can take it in turn to be doubted, while others are held true, or you can whittle the beliefs which can't be abandoned down to a minimum. |
| 6352 | Enumerative induction gives a universal judgement, while statistical induction gives a proportion [Pollock/Cruz] |
| Full Idea: Enumerative induction examines a sample of objects, observes they all have a property, and infers that they all have that property; statistical induction observes a proportion of the objects having the property, and infers that proportion in general. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.4.6) | |
| A reaction: There is also induction by elimination, where it is either p or q, and observation keeps saying it isn't p. A small sample is very unreliable, but a huge sample (e.g. cigarettes and cancer) is almost certain, so where is the small/huge boundary? |
| 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. |
| 6372 | Since every tautology has a probability of 1, should we believe all tautologies? [Pollock/Cruz] |
| Full Idea: It follows from the probability calculus that every tautology has probability 1; it then follows in Bayesian epistemology that we are justified in believing every tautology. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §4.3.1.5) | |
| A reaction: If I say 'a bachelor is a small ant' you wouldn't believe it, but if I said 'I define a bachelor as a small ant' you would have to believe it. 'Bachelors are unmarried' men is a description of English usage, so is not really a simple tautology. |
| 6360 | Scientific confirmation is best viewed as inference to the best explanation [Pollock/Cruz] |
| Full Idea: The confirmation of scientific theories is probably best viewed in terms of inference to the best explanation. | |
| From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §2.3.3.3) | |
| A reaction: A simple claim, but one with which I strongly agree. 'Inference', of course, implies that there is some fairly strict logical thinking going on, which may not be so. I suspect that dogs can move to the best explanation. It is, though, a rational process. |
| 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. |