Q. 2. Do you see any connection between Wittgenstein’s critique of “the Augustinian picture” and the Prototype Theory?

EDIT [March 24th]:

The content of this post has been removed because it did not answer the question and was likely to create confusion. We hope a better version will be online soon.

ape this!

We’re moving to discussing more on prototypes and the main motivation for this view: categorization. This is a good time, and a proper context, to ask ourselves about the relation between the human and the animal mind. Do animals have concepts? Well, animals can tell predators from prey, can’t they? Some animals keep track of complex social relations – if you’re a newbie it will probably hurt you not to know Fred is the alpha male in this community. So what should we say?

Take a look at:

> Susan Rumbaugh on the bonobos

> the late Alex

> chimps kicking &*% in memory tests

Problems of the Classical Theory and their answer in the Prototype Theory

Q1: Consider the following problems for the Classical Theory: psychological plausibility, ignorance and error and typicality. How does the Prototype Theory answer them?

For a long period of time, the Classical Theory has occupied a central place in theorizing about concepts. The reactions to such a theory were inevitable and took the form of critical remarks which eventually developed into other theories regarding the structure of concepts. These new theories tried to resolve the incoherencies and misunderstandings of the Classical Theory: Plato’s problem, the problem of psychological reality, the problem of analyticity, the problem of ignorance and error, the problem of ignorance and error, the problem of conceptual fuzziness and that of typicality effects. One such theory is the Prototype Theory.

Before presenting the three of the problems posed by the Classical Theory and how the Prototype Theory answers them I will sketch the basic characteristics of the two theories.

The Classical Theory considers that concepts have a definitional structure and that in order for them to be applied they must meet a set of necessary and sufficient condition.

There are two essential characteristics of the Prototype Theory that differentiate it from the Classical Theory:

Concepts can be applied by “satisfying a sufficient number of features, where some may be weighted more significantly than others”(Laurence and Margolis, p. 27)

Lack of definitional structure.

1. Psychological plausibility.

Laurence and Margolis consider that “lexical concepts show no effects of definitional structure in psychological experiments.” They give an example of a psychological experiment made by Walter Kintsch. Two subjects were given the task to listen to a set of sentences. They had to indicate as fast as possible the occurrence of a phoneme. Also, in order to be sure that they don’t just listen to the sentences they were asked to repeat the sentence or create a new sentence that had similar meaning. The sentences had the same phoneme positioned in the same place. What differed was the word before the given phoneme: one was more complex than the other in the sense that it had as a constituent the less complex word. Here is the example given by the authors (the word “convinced” is supposed to be the complex term):

The doctor was convinced only by his visitor’s pallor.

The story was believed only by the most gullible listeners.

What Kintsch examined was the reaction times of the subjects for identifying the given phoneme. His findings were that the speed at which the phoneme is identified is unaffected by the complexity of the term (in other words, by its definitional structure).

2. Ignorance and error.

According to the Classical Theory, one can possess a concept only “by representing necessary or sufficient conditions for its application” (Laurence and Margolis, p. 22). However, experience tells us otherwise: in the past, for example, people could have had a different understanding of a concept than we have today; their conception is considered an erroneous and ignorant one but still they had that particular concept. Laurence and Margolis conclude that “It is possible to have a concept in spite of massive ignorance and/or error, so concept possession can’t be a matter of knowing a definition.”

3.Typicality effects.

The Classical Theory implies that “all instances of a given concept are on equal footing” (Laurence and Margolis, p. 24); this means that items in a category cannot be classified as more typical or less typical in comparison to each other. However, in the 1970s psychologists have proven through a series of experiments that the speed at which items are categorized and the errors which occur when categorizing items are directly affected by typicality. This proves that the Classical Theory is inconsistent when it comes to typicality whose “effects can’t be accommodated by classical models.” (Laurence and Margolis, p. 27).

The first two problems of the Classical Theory are resolved by the simple fact that the Prototype Theory implies a lack of definitional structure of concepts.

The third problem seems to be resolved by including the idea of typicality in its model of categorization (The Accumulator Model). The prototype theorists’ arguments are the following:

- the mechanism of categorization is based on finding similarities; similarity is considered to be a graded notion, therefore some items that are part of a given category are considered more typical than the others.

- some items have in more properties in common with the given category and some have less. Therefore some can be considered more typical than others.

All in all, one can consider the Prototype Theory a reinterpretation of the Classical Theory which resolves the problems previously analyzed. However, it too has its downfalls and therefore cannot be considered superior the Classical Theory.

Summary of the 4th class

1.  Last week’s course started with a recap of Wittgenstein’s two separate positions regarding the relation between world and language. The first way of seeing this relation is that depicted in Tractatus Logico-Philosophicus, Wittgenstein’s first and sole consistent work published during his lifetime. In this short book Wittgenstein shows how language and thought can be analyzed using the tools of modern logic. He describes a theory in which words stand for objects in the world and, hence, language mirrors the world. This view is significantly influenced by the ideas of Frege (to a larger extent) and Russell.

2.   Later, in his maturity writings, Wittgenstein does what no other philosopher had ever done before: he totally brakes with his previous way of thinking. In Philosophical Investigations (PI) Wittgenstein reconsiders the relation between world and language, and the way this is reflected in thought. In fact, he admits he had been wrong and rejects the Tractatus. He initially wanted the two works – Tractatus and Investigations –to be published together so the reader could see the radical differences between the ideas presented. In the PI Wittgenstein shows that there is nothing wrong with natural language (in Tractatus he stated, following Frege, that all the problems of philosophy dwell in the fact that natural language is imperfect Sorry, this was the wrong way to put it; there’s nothing wrong with natural language, Wittgenstein does not follow Frege here; in this case Wittgenstein didn’t change his mind moving from the Tractarian period to his later ideas;  see e.g. 3.032; to the extent a language is a language, it is in perfect logical order; of course, we tend to force language beyond its expressive powers), the problems come from the fact that people use language wrongly. Wittgenstein proposes a new way of looking at philosophy: as a therapeutic activity whose purpose is to help the thought to escape the deep incumbent automatisms. These automatisms are the consequence of using language wrongly.

3.   Before saying something about the paragraphs we managed to discuss in class, let me go back to the first paragraph where Wittgenstein presents one of the most powerful misconceptions concerning language: the representational view of language, or the “Augustinian picture”. According to this view, language is a set of labels (names) that apply to the world and describe “entities” in the world (things, phenomena, actions, attributes). Wittgenstein rejects this “picture” and shows how this view may hold for special “narrowly circumscribed regions” of language (see paragraphs 2 and 3). Such particular situations may include proper names and definite descriptions, for example (remember Frege’s analysis of the relation between “Aristotle”, “Plato’s pupil” and “the teacher of Alexander the Great”). Wittgenstein proposes a range of intellectual exercises regarding simple cases of learning and natural language use in order to identify the weaknesses of the “Augustinian picture” of language. It is here where he introduces the concept of language-game. Although he never fully explained this concept, it is fundamental for the core idea of the PI.  Language-games – simple (social) activities interwoven with typical use of certain words – help us better grasp the specificity of natural language. Language is embedded in social structure and linguistic actions and other actions mix together.

4.   The first paragraph we discussed is the one in which Wittgenstein’s imaginary opponent accuses him of “taking the easy way out” (65): providing the reader with too many examples of language-games without specifying what unifies all these examples, what is common to all of them, i.e. a definition of the language-game. It is the mere concept of (language-) game (and a little later, the concept of “family resemblance”) that Wittgenstein uses to point out the vulnerabilities of the Classical Theory.

5.   In 66, Wittgenstein shows how what we call “game” cannot be defined (there are people who think otherwise, e.g.  Bernard Suits, who considers that games can be defined) , meaning that we cannot provide a set of necessary and sufficient conditions that will fix the features for all things that fall under the concept of “game”. Wittgenstein doubts that we can provide conditions that would capture the commonalities between all games. In fact, he urges us to “look and see” different types of games (board-games, ball-games, card-games, etc.) and search for what is common to all. We’ll discover that common to all are similarities and relationships, but no features (remember here the example that George discussed in class with the features of several pieces of furniture).

6.      Further on, Wittgenstein introduces the concept of family resemblance for characterizing the similarities between different sorts of games (67). This concept is rooted in the analogy with the members of a family. How can we explain concepts, if not by providing definitions for them? Well, we can explain how hey relate to other concepts, how they resemble a family. But the opponent from the imaginary dialogue might object to this by saying that what is common to concepts such as game is the “disjunction of all their common properties”. At this point Wittgenstein replies that this is nothing more than “playing with words”. For it need not be so that the concept of game (or number) is explained as “the sum of the corresponding set of sub-concepts”,  or as the disjunction of, say, board-games n card-games n ball-games n etc. We may explain the concept – decide if an item falls under the concept or not –by identifying the relationships, the similarities between the items and their use in a language.

7.   In the sections 68-70, Wittgenstein addresses the problem of concept boundary. According to the Classical Theory, by giving the definition of a concept we also fix the limits of that concept. The author of the PI thinks, on the contrary, that the extension of a concept need not be “closed by a frontier”. But if we look at the way people use language we realize that they employ a word (“number”, for example) for a rigidly limited concept. Therefore, concepts have strict borders. This is not exactly true, says Wittgenstein, for we cannot give the boundary of a concept (set by its definition), but we can draw one. And we draw the boundary of a concept when we use that concept for a specific purpose. We can redefine a concept for technical purposes – we redefine “number” for using it in mathematics or physics, “game” for applying it to a certain activity in which two or four people throw a ball to each other by using rackets and obeying to certain rules.

8.   But if concepts lack strict borders how can we know if something falls under a concept or not? Wittgenstein admits that there are rules that specify what items the extension of a concept may include. However, we don’t need to specify all these rules when we use a concept. Remember the examples he gives in 69 and 70: the definition of a pace and the definition of a plant. We can draw a boundary of a concept and still use it inexactly; the exactness of a concept is relative to a specific purpose and to a set of “language-games”.

9.   In 71, Wittgenstein discusses the problem of “blurred concepts”. It is an issue that had been addresses before, by Frege, under the name of “vague concepts”. Frege thought that these particular concepts should be abandoned, removed from language, as we “cannot do anything with them”. On the contrary, Wittgenstein admits that we use lots of blurred concepts and manage to communicate and understand each others. When using a concept, we don’t always need to be exact (except for the technical purposes, where we may want to give definitions). If we need to explain to someone what a game is, we can give him or her examples which should be taken in a particular way. This doesn’t mean that we explain them the concept, but that we help them see the similarities and the relationships between those examples. Another way of dealing with blurred concept is to point to the entity in the world expressed by a concept (ostensive use). Remember here the example with the glass of water (if someone is thirsty and ask for a glass of water, he or she doesn’t have to be exact and ask for 350 milliliters of water so that others understand what she means).

10. To sum up, in the paragraphs we discussed Wittgenstein proposes an alternative to the Classical Theory and to the idea of the existence of a “common core” to all things specified by a word. He considers that the semantic coherence of the majority of expressions (and concepts) lies in their family resemblance and not in their common characteristics stipulated by their definitions. Therefore, definitions don’t seem to work for concepts as much as the proponents of the Classical Theory thought. We should look and see something else that may be o a greater help; something such as family resemblance.

update: next class

There is a small change in the syllabus. We will not move directly to Rosch’s paper, so, for next time, please read section #3 [pages 27-43] of the introductory chapter from Margolis&Laurence. It’s in the reader and you can also find it online here. 

Neural Networks

I have mentioned in the 2nd seminar something about neural networks. It would be interesting to have a look at it here    or read much more about it here. I recommend reading at least a bit of the first source, as it might get you another perspective on how the mind works and what concepts can be at another level.

summary of the 3rd class by Diana

Diana was a bit late, but she wrote a very good - and concise – summary. My comments, as before, in square brackets. 

In the 3^rd class we disscused:

- the distinction between types and tokens
- Frege’s sense-reference distinction
- a brief biography of Wittgenstein

1. The type-token distinction is useful in our discussion about concepts. Very roughly, this marks a distinction between sorts (types) of things, and instances (tokens) of sorts of things. For example, when we say ‘apples are red’ and ‘lemons are yellow’, we have two types (apples, lemons – fruits and red, yellow – colours) and 2 tokens for each type.

[Good. Let's also say why the type/token distinction is useful - because it explains how we can share concepts. That is, we share concept types, e.g. FRUIT, though concept tokens are 'attached' to individual minds - when we both think about fruits there is something in your head, and there is something in mine; two different things, since they have different locations - but they belong to the same type, they're the same kind of beast.]

2. Frege: “Sense and Reference” (1892)
We talked during our second class about the classical theory of definition, according to Aristotle. Who is Aristotle? He was Plato’s student. He was the teacher of Alexander the Great. He was the author of the classical theory of definition. We have here 3 senses of the expresion “Aristotle” and one referent – Aristotle. We can think of senses as ‘modes of presentation’ of the same referent. There are also nonrefering expressions – expressions that don’t have a reference, for example “the greatest integer”. Since there is not a greatest integer, the expression doesn’t refer to anything. But it seems perfectly meaningful, since we seem to understand claims like “The greatest integer is larger than one million”. Employing the sense-reference distinction, we can say that the expression has a sense but lacks a reference.Another important distinction is the one between senses and ideas. Two persons can have the same sense about an object to which they refer (for example, they both define the Moon as ‘Earth’s natural satellite”). Let’s imagine that we are watching the Moon through a telescope: we have the object (referent) – the Moon. The image on the telescope is an objective image of the referent (the sense). But the way we see this image is different, the retinal image of the objective image is different for each of us. This retinal image is our idea of the moon, which is subjective, psychological. The sense (objective image) is public.

[Both the Aristotle example and the Moon analogy can be found in the first few pages of Frege's paper]

We also discussed about subjectivity. Each person has a different point of view, he gives a certain interpretation to facts, language, experiences. Can we talk about objectivity (a distant, and unbiased point of view)? A proof we can talk about objectivity is that we understand each other. Relativistic doctrines try to show that some central aspect of experience, thought, evaluation, or even reality is somehow relative to something else (our subjective interpretation).

 [Here we can also point to something that Frege says. Translation poses all kinds of problems about 'importing' meaning from one language to another, and about subjectivity - traduttore traditore. Frege says that a good translation should capture the sense of what is said. Since natural languages are imperfect according to him, a translation is still OK if it misses what he calls the 'emotional coloring' of a text. So the suggestion is that semantics/meaning and psychology should stay separate. So e.g. Alex tried his best with Rilke in the previous post - but do they say the same?]

summary of the 3rd class by Alex

Alex sent me the following summary. The words in blue are Wikipedia links – if they don’t work, please do your own search. Congrats Alex for doing some extra research, but don’t count that much on Wikipedia.

My comments on what Alex wrote are inserted in square brackets: e.g. [comment]. I mean to clarify some issues – this was genuinely hard stuff. 

‘We started our third session with repeating Frege’s Principle, you might also call the principle of compositionality. It states that in a meaningful sentence, the rules of composition remain, if the lexical parts are taken out of the sentence. So Alexander = Alexander. No doubt on that. As soon as you know what the sign = mean, you might agree. But what about the information Alexander = German. Now you have to check whether the sentence is true or false. If I show you my passport, you might agree with this statement too.  

[There are a few things here:

1. The principle of compositionality says that the meaning of a sentence is a function, i.e. a composition according to some rules, of the meaning of each element in the sentence. So, 'Dogs bite' gets whatever meaning it has from the meaning of 'dog' and the meaning of 'bite'.

2. Now, what we discussed is only indirectly connected with compositionality. We don't really deal with meanings of whole sentences, but with the meanings of their parts - of words. We do that because we identified pre-theoretically concepts with word meanings.

3. Alex = Alex VS Alex = German. Now we're getting to something, but we need to be very careful with the examples. The '=' stands for 'is' in both cases and Alex was thus a bit misguided. In 'Alex=Alex' the '=' means identity, Alex is Alex. But in 'Alex=German' it means that Alex has a property, that of being German. We are only interested in the 'is' of identity, so we need to modify the second example, which uses an 'is' of predication. We should use proper names or a description that captures one individual [the noun 'German' applies to millions]. So let’s use this: ‘Alex=Herr Kempf’.

4. Now we have the problem. Alex=Alex is true, but not informative. Alex=Herr Kempf is also true, but informative – it tells you something new. Frege’s question is: how can that be given the assumption that the meaning of a name is the object it names. The two sentences above are about Alex – they say the same thing. Both should have the same status – but they obviously don’t. So there is more to meaning than the objects named. This something more is sense.]

As I understand Frege a concept is a proposition, which consists of an expression that signifies an object together with a predicate. Alexander is German therefore is an expression, which defines me as German. [Let's just bracket this part. Frege uses a special notion of concept. It is nota proposition. For him, a concept is expressed by an incomplete expression such as '...is a student'. Once you plug in a name, you have a complete sentence that expresses what Frege calls 'a thought'. Take home message: forget what Frege calls concepts; what we ask is if we can derive a notion of concepts from what he calls sense.]In class we discussed about the words reference, sense and idea according to Frege. As I understood George right, a sense is the result of a combination from an object and a fitting word. The word therefor is a reference. As we build sentences with sense we can transport ideas. 

[Alex is right to point to the distinction between reference, sense, and idea. This is a crucial point. The reference is just the object; the reference of 'Moon' is the Moon up there in the sky; the sense is a description or a definition of the object; it is the 'interface' through which we 'encounter' the object - we don't grasp 'naked' objects; so the sense of 'Moon' might be: 'Earth's natural satellite'.

So in the Alex/Herr Kempf example above the difference can be explained after all. It is not a difference in reference, but a difference in sense. 'Alex' and 'Herr Kempf' present the same object to us in two differentways. Frege does talk about senses as 'modes of presentation'.

What about the idea? Here is another crucial point. Ideasare in our minds, they are psychological. But Frege did not want senses to be psychological. If they are in our minds, then how could we communicate them?! How could we ever know what we mean by what we say - we don't see intominds. Frege thought senses are objective entities - they are thus public, so communicable. Sense are somewhat like numbers for Frege. The number one is not something in your hear, but it is not material either.

 We tried to say againstFrege that something can be BOTH in our minds AND communicable. We wanted to say that senses are a kind of ideas too, but they can't differ radically between individuals. See again the first pages of your first reading for a discussion of subjective/objective. See also the quotations from Frege on your first handout.]

Thinking abstract I see Frege’s point. Due to the fact I’am German too, I feel the need of structure and order. But is it practical relevant that we can distinguish between word, concept and meaning? Going back to the example Alexander = Alexander. Is this really a truthful sentence? As Alexander has been the most popular prename for years in Germany, there will be many others that bear my name. But am I somebody else? Or: I = somebody? 

[Good question - how do Frege's distinctions help us understand our linguistic practice? Well, do they? Can we talk differently about the same stuff? Misunderstading exists - how do we explain it? Alex is right to say that a Fregean passion for order - i.e. logic - might not help us. But we need then some other view of the issues. Wittgenstein?

Alex, of course we share our names with many people - but we can idealize and consider names to be unique. As long as 'Alex' has the same reference on both sides of the identity sign, the sentence is always true. So don't worry, you are yourself .

Enjoy what Alex says in the following, my nasty interference stops here. Nice touch there with Rilke. Anybody with other versions of the translation - maybe in Romanian?]

This leads us to the next topic we discussed. The ideas of Wittgenstein, an Austrian philosopher with a quite interesting vita. We spend some time in the class to trace his adventorous life. Did you know Wittgenstein attended the same school as Adolf Hitler? Being the youngest of eight children of one of the most prominent and wealthy families Austro-Hungarian empire Wittgenstein was surrounded since his youth by illuster figures. A look at his vita at wikipedia is highly recommended. 

In last class we went not too deep into detail. Wittgenstein’s idea will be the topic of the coming session. However it is good to know that there is a difference between the young and the late Wittgenstein. The only book published by Wittgenstein in his lifetime was the Tractatus Logico-Philosophicus in 1921. The 32-years young Wittgenstein, influenced by Arthur Schopenhauer and the new systems of logic put forward by Bertrand Russell and Gottlob Frege, believed he had solved all the problems of philosophy in this book. 

But philosophy is not Hollywood, so there is no Happy End. The late Wittgenstein renounced or revised much of his earlier work. His development of a new philosophical method and a new understanding of language culminated in his second magnum opus, the Philosophical Investigations, which was published posthumously. Critics still quarrel among each other, how to interpret this book. If there are tow opinions about the young Wittgenstein, there are four about the old one is a common joke. In any case Wittgenstein did neither explain the world nor the language finally. So still achievemens can be made by us. 

I, for one agree with a metaphor of the late Wittgenstein. 

“Our language can be seen as an ancient city: a maze of little streets and squares, of old and new houses, and of houses with additions from various periods; and this surrounded by a multitude of new boroughs with straight regular streets and uniform houses.” 

Wittgenstein, Philosophical Investigations, § 18  
 

One of my favourite German lyricists is Rainer Maria Rilke, who was born 14 years before Wittgenstein. Rilke, a dreamer and romanticist, was the straight opposite of the young Wittgenstein. In 1898 he published a poem I would love you to see and hear (http://www.youtube.com/watch?v=JOVsoapTETk). As you won’t understand the meaning I will translate it in a poor English … 
 

Menschen Wort

word of the people 

Ich fürchte mich so vor der Menschen Wort. 
I’m afraid of the word of the people

Sie sprechen alles so deutlich aus: 
They pronounce everything that explicit

Und dieses heißt Hund und jenes heißt Haus, 
This is named a dog and this is named a house

und hier ist Beginn und das Ende ist dort. 
And here is the beginning and the end is over there.

Mich bangt auch ihr Sinn, ihr Spiel mit dem Spott, 
I also worry about their senses, the way they use sarcasm 

sie wissen alles, was wird und war; 
They know everything that has been and will be

kein Berg ist ihnen mehr wunderbar; 
No more mountain seems delightful to them

ihr Garten und Gut grenzt grade an Gott. 
Their garden, their goods and chattels adjoin to god.

Ich will immer warnen und wehren: Bleibt fern. 
I will forever warn and fend: Stay away!

Die Dinge singen hör ich so gern. 
I love to hear how the things sing

Ihr rührt sie an: sie sind starr und stumm. 
You touch them, they stand rigid and silent

Ihr bringt mir alle die Dinge um. 
You kill all those things. 

Rainer Maria Rilke‘

update: next class & more

We are a bit late with the summary of the 3rd class - we should have it [we will] later today.

 To make sure those who haven’t been in class last time know what to prepare: we will read and discuss sections 65 to 78 from Wittgenstein’s Philosophical Investigations. Do read them before the class.

In your reader you have a larger part of the Investigations. It wouldn’t hurt to read more. Try sections: 3, 7, 11 – 14, 23, 32, 36, 43, 79, 92, 97, 111, 115, 122-124, 126, 130, 133. These are section numbers, not page numbers. Take a look at the text or the online version [I e-mailed you the link, and you can also find it below or in 'webgate']

Perhaps some things were not clear, stuff like:

- attendance is not optional; last time, 5 of you – in a such a small class – informed us directly or indirectly, the day of the course, that they cannot come. Let me remind you that you chose to take this class and were informed in advance about the schedule, requirements etc. We kindly but firmly inform you that such conduct is not acceptable.

- please, read the requirements again; Friday is the 4th meeting, out of 6 in the 1st unit. High time to start writing reaction papers! Reaction papers should be written and sent before the class in which we discuss the paper in question. So e.g. this week you should have written about the Wittgenstein excerpt. If we knew how you dealt with the issues before the class, that would help focus the class on what seemed important or controversial to you. That is the purpose of reaction papers to begin with.

If reaction papers are too hard, fine, we give you the option of writing a summary of one class with a colleague. There are not enough classes left in the 1st unit for all of you though.

the outer limits

At some point during the last class I said, with reference to Frege’s notion of objectivity (i.e. shareability) of sense (Sinn) that it is a given that communication is possible, because there is a level at which inter-subjectivity works – a level at which we are similar enough, or similar in some relevant aspects. The problem is how to conceive of this level? I won’t say more here – since Diana and Alex will write a summary for the last class.

Let me just remind you (well, this holds for those of you who were there) that I also mentioned that this given – the fact that our minds are not (completely) opaque, that there are ‘windows’ between subjects, that meanings (i.e. concepts) can be shared – can be questioned when we go beyond the outskirts of the clinically normal mind. (Think also of an alien mind. What about an animal mind?) Could we understand a person that is deeply schizophrenic?

Here is a quote from Giovanni Stanghellini ‘Schizophrenia and the sixth sense’, p.132 (in Chung, Fulford and Graham edts. Reconceiving Schizophrenia, Oxford University Press 2007):

‘A second layer of displacement concerns the feeling I have that something is lacking while trying to communicate with a schizophrenic person. Phenomenologists think that schizophrenic persons show an enhanced aptitude to the bracketing of common-sense experiences and shared meanings [...] The same happens with the meanings we usually attach to words, so that we often lack a common ground for understanding each other. I may for instance have the impression that we use the same word but we attach different meanings to it. Thus, I have the sensation that he [the schizophrenic] does not share the same horizon of meanings that I take for granted to share with the other persons I usually get in touch with. ’

What do you think? Reflect also on what it might be to ‘attach a meaning to a word’? Is this something you do in your head? Does it depend on social, cultural or linguistic infrastructure (i.e. stuff outside your head)?

One more quote, from the same paper, p. 138:

‘If the taken-for-granted becomes explicit, ipso facto it becomes an object for reflection and doubting. This is the common premise for philosophy and insanity.’