WEBVTT 00:10.310 --> 00:16.240 OK, so that was the classical theory concept, let's dive into the prototype theory concept now. 00:17.230 --> 00:21.120 So the prototype theory concept is based on Wittgenstein's heritage. 00:21.280 --> 00:26.050 So that's the late Wittgenstein work that it did philosophical investigations, for example. 00:27.250 --> 00:30.960 It's a very good book, I should say, actually have it here. 00:31.210 --> 00:37.230 It's a Swedish style, but it's very much read from recommended anyway. 00:38.020 --> 00:44.230 So Eleanor Rosch was the psychologist who made this famous in a broader sense when it comes to categories 00:44.230 --> 00:44.830 and concepts. 00:45.130 --> 00:46.720 And she called it a prototype theory. 00:47.470 --> 00:52.200 So and Eleanor, she's still working in Berkeley as a professor of psychology. 00:52.510 --> 00:55.140 So here's a famous quote from her work regarding this. 00:56.020 --> 01:01.630 So when describing categories analytically, most traditions of thought have treated category membership 01:01.630 --> 01:06.970 as a digital all or non phenomenon that is much work in philosophy. 01:07.000 --> 01:13.060 Psychology, linguistics and anthropology assumes that categories are logical bound entities, membership 01:13.060 --> 01:20.020 in which is defined by items possession of a simple set of criteria or features in which all instances 01:20.020 --> 01:24.140 possessing the criteria or attributes have a full and equal degree of membership. 01:24.670 --> 01:31.810 In contrast, it has recently been argued that some natural categories are analog and must be represented 01:31.810 --> 01:35.760 logically in a manner which reflects the analog structure. 01:36.280 --> 01:42.310 So you can very much see here that she's first describing what I call the classical theory in the last 01:42.310 --> 01:42.750 lecture. 01:42.970 --> 01:48.610 And she also points out regarding the Plato's problem and the topicality effect, all the problems that 01:48.610 --> 01:49.730 relate to such a view. 01:50.350 --> 01:52.210 So what is the prototype theory about? 01:52.210 --> 01:57.140 And I talked a little about it already when we talked about the typical artifact problem. 01:58.330 --> 02:04.000 So according to a prototype theory, instead a concept he doesn't have a definitional structure but 02:04.000 --> 02:13.060 has a probabilistic structure in that something falls under the concept C just in case it satisfies 02:13.060 --> 02:17.440 a sufficient number of properties encoded by these constituents. 02:20.580 --> 02:24.100 So the prototype includes what object tends to possess. 02:24.630 --> 02:32.790 So usually also then one object or a couple of objects are picked as a prototype for that class of things 02:32.790 --> 02:33.780 for that concept. 02:34.260 --> 02:40.410 So in this case, that you might have psychologically, in your mind when you're thinking about a bird, 02:40.710 --> 02:47.220 then you have maybe a typical prototype of a bird in your mind, and then you apply that to a number 02:47.220 --> 02:47.610 of birds. 02:47.730 --> 02:52.590 But you also know, like just knowledge wise, that the penguin is actually a bird as well. 02:53.160 --> 02:58.170 But that is probably not the first thing you get into mind when you hear the concept bird. 02:59.570 --> 02:59.940 Right. 03:01.580 --> 03:05.930 So and as I said, this is very much heritage from late Wittgenstein work. 03:08.630 --> 03:16.220 Something that he talked a lot about was games, language games, all different kinds, but he also 03:16.220 --> 03:18.290 used game as an example for this. 03:18.770 --> 03:26.390 So if you look at the different types of things here, so you have golf, swimming, fishing, poker, 03:26.870 --> 03:30.620 polo, solitaire, chess. 03:32.800 --> 03:33.970 All unifies Tom. 03:34.910 --> 03:35.630 Is. 03:36.770 --> 03:42.100 Again, right, but they're quite different, right? 03:42.140 --> 03:49.070 There's very much difference between chess and golf maybe, and there are some similarities maybe between 03:49.070 --> 03:57.200 poker and solitaire and some similarities, maybe between solitaire and fishing, but they don't have 03:58.310 --> 04:01.360 a set of attributes that applies to all of them. 04:02.240 --> 04:08.850 So Wittgenstein was saying here is that people apply game to a range of disparate human activities that 04:08.880 --> 04:12.640 better to one another, only what one might call the family resemblance. 04:12.830 --> 04:16.000 And he meant like a family, like a family of people. 04:16.010 --> 04:17.720 So you have a father and a son. 04:18.110 --> 04:21.260 They're not the same person, but they might have some resemblance. 04:21.620 --> 04:23.360 And the son and the mother as well. 04:23.600 --> 04:24.770 And the mother and the daughter. 04:24.770 --> 04:26.400 And the son and a daughter and so on. 04:28.310 --> 04:33.160 So he was thinking about things that they have family resemblance. 04:33.170 --> 04:36.200 That doesn't mean that they have exactly the same set of attributes. 04:38.600 --> 04:42.310 Another thing that he was talking about was kind of fuzzy concepts. 04:43.580 --> 04:44.900 So here's what he said about that. 04:46.190 --> 04:51.900 It is clear that the degree to which the short picture can resemble the blurred one depends on the latter's 04:51.920 --> 04:59.130 degree of vagueness for imagine having to sketch a sharply defined picture corresponding to Leard one. 05:00.200 --> 05:07.920 So what he was saying here is that you cannot define a concept more clear than it appears to us selves 05:08.090 --> 05:09.010 in our minds. 05:09.530 --> 05:09.880 Right. 05:10.510 --> 05:14.520 So you cannot force clearness onto a picture that is vague. 05:15.860 --> 05:18.850 So is this a red rectangle? 05:20.500 --> 05:20.760 Maybe. 05:22.050 --> 05:29.180 Yeah, but if so, how much blurred must it be until we will actually say that is a red triangle? 05:30.290 --> 05:34.940 So, see, my point here is that we seem trying to and that is also what I was just talking about, 05:34.940 --> 05:40.610 that most of the concepts of Ihara more analog are not that digital, but the classical theory applies. 05:44.570 --> 05:54.170 And a third very famous quote from Wittgenstein is comparing, saying and knowing, so he said like 05:54.170 --> 06:04.340 this Compare knowing and saying how many feet high multipliers, how the word game is used, how a clarinet 06:04.340 --> 06:10.130 sounds if you are surprised that the one can know something. 06:12.980 --> 06:18.360 And not be able to say it, you are perhaps thinking of a case like that first. 06:18.380 --> 06:20.270 Certainly not one like the third. 06:21.500 --> 06:27.440 So what is saying here is that you can, of course, know how high -- you can say it in meters 06:27.440 --> 06:28.250 if you know it. 06:29.450 --> 06:32.480 When it comes to the word game, it gets a little bit more trickier. 06:32.480 --> 06:41.930 Just as we saw you might not actually pinpoint one or two even that attribute that applies to all games. 06:42.590 --> 06:49.460 And then if you take an even more like, fussier concept, like how the clarinet sounds, you know exactly 06:49.460 --> 06:50.930 how it sounds, you know that. 06:51.290 --> 06:53.270 But you have a very hard time saying it. 06:53.840 --> 07:00.050 And if you have a very hard time saying it, you will have a hard time defining it in a classical way. 07:04.750 --> 07:11.680 So that is what the prototype theories about that it is more of a probabilistic structure than a binary 07:11.680 --> 07:16.120 structure, but there are problems with the prototype theory as well. 07:16.480 --> 07:18.400 So here are some of the problems. 07:19.360 --> 07:27.160 The first problem is that concepts like prototypes, many concepts like prototypes, there are a lot 07:27.160 --> 07:29.770 of concept that we have a clear prototype picture. 07:30.160 --> 07:35.860 We talked about the burden here, for example, or you can talk about a fish equally very simple to 07:35.860 --> 07:37.600 find kind of a prototype. 07:38.020 --> 07:44.470 But if you have more combined concepts that you easily could imagine and have a concept about, then 07:44.470 --> 07:45.320 it's a little bit harder. 07:45.610 --> 07:49.490 So a pet fish that lives in Armenia and recently swallowed their owner. 07:49.930 --> 07:52.810 So can you say to me that you have a prototype for that? 07:54.550 --> 08:03.340 Yeah, probably not so many concepts that we actually can have, we still won't have prototypes for, 08:04.660 --> 08:07.290 and there's no competition ality either. 08:07.660 --> 08:13.750 So we talked about the competition constitutionality in the classical theory, but the man and the unmarried 08:13.750 --> 08:14.170 and so on. 08:14.800 --> 08:19.570 But it's much harder to actually make a composition out of the prototypes. 08:20.140 --> 08:26.490 So prototypes are often not functions of the prototypes of the constituent concepts. 08:27.910 --> 08:35.230 So if you have this fish again and you have this maybe a pet, so let's say that that is the typical 08:35.230 --> 08:38.530 prototype of a pet and this is a typical prototype of a fish. 08:38.920 --> 08:45.010 However, combined, you know, about a pet fish, you won't get a pet fish. 08:45.010 --> 08:47.590 So you have a prototype of the pet fish here like here. 08:47.740 --> 08:51.250 But that is not a combination of a fish and a pet prototype. 08:52.060 --> 08:52.420 Right. 08:56.320 --> 08:57.310 So think about that. 08:57.580 --> 09:05.440 So that was the kind of two problems raised when thinking about issues related to Prototyp theory. 09:06.610 --> 09:11.640 In the next lecture, we're going to talk about what is called the theory theory. 09:11.650 --> 09:17.380 And also here, I will highlight what it is about and some problems that arise from using it. 09:18.600 --> 09:19.120 Very good.