OK, so that was the classical theory concept, let's dive into the prototype theory concept now.
So the prototype theory concept is based on Wittgenstein's heritage.
So that's the late Wittgenstein work that it did philosophical investigations, for example.
It's a very good book, I should say, actually have it here.
It's a Swedish style, but it's very much read from recommended anyway.
So Eleanor Rosch was the psychologist who made this famous in a broader sense when it comes to categories
and concepts.
And she called it a prototype theory.
So and Eleanor, she's still working in Berkeley as a professor of psychology.
So here's a famous quote from her work regarding this.
So when describing categories analytically, most traditions of thought have treated category membership
as a digital all or non phenomenon that is much work in philosophy.
Psychology, linguistics and anthropology assumes that categories are logical bound entities, membership
in which is defined by items possession of a simple set of criteria or features in which all instances
possessing the criteria or attributes have a full and equal degree of membership.
In contrast, it has recently been argued that some natural categories are analog and must be represented
logically in a manner which reflects the analog structure.
So you can very much see here that she's first describing what I call the classical theory in the last
lecture.
And she also points out regarding the Plato's problem and the topicality effect, all the problems that
relate to such a view.
So what is the prototype theory about?
And I talked a little about it already when we talked about the typical artifact problem.
So according to a prototype theory, instead a concept he doesn't have a definitional structure but
has a probabilistic structure in that something falls under the concept C just in case it satisfies
a sufficient number of properties encoded by these constituents.
So the prototype includes what object tends to possess.
So usually also then one object or a couple of objects are picked as a prototype for that class of things
for that concept.
So in this case, that you might have psychologically, in your mind when you're thinking about a bird,
then you have maybe a typical prototype of a bird in your mind, and then you apply that to a number
of birds.
But you also know, like just knowledge wise, that the penguin is actually a bird as well.
But that is probably not the first thing you get into mind when you hear the concept bird.
Right.
So and as I said, this is very much heritage from late Wittgenstein work.
Something that he talked a lot about was games, language games, all different kinds, but he also
used game as an example for this.
So if you look at the different types of things here, so you have golf, swimming, fishing, poker,
polo, solitaire, chess.
All unifies Tom.
Is.
Again, right, but they're quite different, right?
There's very much difference between chess and golf maybe, and there are some similarities maybe between
poker and solitaire and some similarities, maybe between solitaire and fishing, but they don't have
a set of attributes that applies to all of them.
So Wittgenstein was saying here is that people apply game to a range of disparate human activities that
better to one another, only what one might call the family resemblance.
And he meant like a family, like a family of people.
So you have a father and a son.
They're not the same person, but they might have some resemblance.
And the son and the mother as well.
And the mother and the daughter.
And the son and a daughter and so on.
So he was thinking about things that they have family resemblance.
That doesn't mean that they have exactly the same set of attributes.
Another thing that he was talking about was kind of fuzzy concepts.
So here's what he said about that.
It is clear that the degree to which the short picture can resemble the blurred one depends on the latter's
degree of vagueness for imagine having to sketch a sharply defined picture corresponding to Leard one.
So what he was saying here is that you cannot define a concept more clear than it appears to us selves
in our minds.
Right.
So you cannot force clearness onto a picture that is vague.
So is this a red rectangle?
Maybe.
Yeah, but if so, how much blurred must it be until we will actually say that is a red triangle?
So, see, my point here is that we seem trying to and that is also what I was just talking about,
that most of the concepts of Ihara more analog are not that digital, but the classical theory applies.
And a third very famous quote from Wittgenstein is comparing, saying and knowing, so he said like
this Compare knowing and saying how many feet high multipliers, how the word game is used, how a clarinet
sounds if you are surprised that the one can know something.
And not be able to say it, you are perhaps thinking of a case like that first.
Certainly not one like the third.
So what is saying here is that you can, of course, know how high -- you can say it in meters
if you know it.
When it comes to the word game, it gets a little bit more trickier.
Just as we saw you might not actually pinpoint one or two even that attribute that applies to all games.
And then if you take an even more like, fussier concept, like how the clarinet sounds, you know exactly
how it sounds, you know that.
But you have a very hard time saying it.
And if you have a very hard time saying it, you will have a hard time defining it in a classical way.
So that is what the prototype theories about that it is more of a probabilistic structure than a binary
structure, but there are problems with the prototype theory as well.
So here are some of the problems.
The first problem is that concepts like prototypes, many concepts like prototypes, there are a lot
of concept that we have a clear prototype picture.
We talked about the burden here, for example, or you can talk about a fish equally very simple to
find kind of a prototype.
But if you have more combined concepts that you easily could imagine and have a concept about, then
it's a little bit harder.
So a pet fish that lives in Armenia and recently swallowed their owner.
So can you say to me that you have a prototype for that?
Yeah, probably not so many concepts that we actually can have, we still won't have prototypes for,
and there's no competition ality either.
So we talked about the competition constitutionality in the classical theory, but the man and the unmarried
and so on.
But it's much harder to actually make a composition out of the prototypes.
So prototypes are often not functions of the prototypes of the constituent concepts.
So if you have this fish again and you have this maybe a pet, so let's say that that is the typical
prototype of a pet and this is a typical prototype of a fish.
However, combined, you know, about a pet fish, you won't get a pet fish.
So you have a prototype of the pet fish here like here.
But that is not a combination of a fish and a pet prototype.
Right.
So think about that.
So that was the kind of two problems raised when thinking about issues related to Prototyp theory.
In the next lecture, we're going to talk about what is called the theory theory.
And also here, I will highlight what it is about and some problems that arise from using it.
Very good.