Philosophical Investigations (Philosophische Untersuchungen), along with the Tractatus Logico-Philosophicus, is one of the two major published works by 20th century philosopher Ludwig Wittgenstein. In it, Wittgentein discusses numerous problems and puzzles in the fields semantics, logic, the foundations of mathematics and the nature of consciousness and puts forth his view that conceptual confusions surrounding language use are at the root of most philosophical problems. The work is generally considered one of the most important philosophical works of the twentieth century and it continues to influence current philosophy of mind and language.

Editions

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The book was not ready for publication when Wittgenstein died in 1951. G. E. M. Anscombe translated Wittgenstein's manuscript and it was first published in 1953. It is now in its third edition which incorporates Anscombe's final revisions, and has been repaginated.

There are two popular editions of Philosophical Investigations, both translated by Anscombe:

• Prentice Hall, 1999 (ISBN 0024288101)
• Blackwell Publishers, 2001 (ISBN 0631231277). This edition includes the original German text in addition to the English translation.

The text is divided into two parts, consisting of what Wittgenstein calls, in the Preface, Bemerkungen (translated by Anscombe as "remarks"). Preface In the first part these remarks are rarely more than a paragraph long, and are numbered sequentially. In the second part the remarks are longer, and numbered using Roman numerals. In the Index, remarks from the first part are referenced by their number rather than page; however references from the second part are cited by page number.

Method

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Philosophical Investigations is unique in its approach to philosophy. Most philosophical texts present a philosophical problem, summarize and critique various alternative views on the subject, present a thesis on how to solve the problem, and then provide argumentation in favour of the thesis. In contrast, Wittgenstein's book treats philosophy as an activity, rather along the lines of Socrates famous method of maieutics, asking the reader to work through various problems and do the actual work of philosophy. Rather than presenting a philosophical problem to be solved and a solution, it engages in a dialogue, where Wittgenstein provides an example situation, articulates how one might be inclined to think of the situation, and then shows why one's inclinations suffer from conceptual confusion. For example, here is an excerpt from the first entry in the book:

"...think of the following use of language: I send someone shopping. I give him a slip marked 'five red apples'. He takes the slip to the shopkeeper, who opens the drawer marked 'apples', then he looks up the word 'red' in a table and finds a colour sample opposite it; then he says the series of cardinal numbers—I assume that he knows them by heart—up to the word 'five' and for each number he takes an apple of the same colour as the sample out of the drawer.—It is in this and similar ways that one operates with words—"But how does he know where and how he is to look up the word 'red' and what he is to do with the word 'five'?" Well, I assume that he 'acts' as I have described. Explanations come to an end somewhere.—But what is the meaning of the word 'five'? No such thing was in question here, only how the word 'five' is used." §1

This is a typical example of the style throughout the book. We can see each of the steps in Wittgenstein's method:

• The reader is presented with a thought experiment: someone sent shopping with an order on a slip.
• Wittgenstein articulates what the reader's reaction may be: "But how does he know where and how he is to look up the word 'red' and what he is to do with the word 'five'?... But what is the meaning of the word 'five'?"
• Wittgenstein shows why the reader's reaction was misguided: "No such thing was in question here, only how the word 'five' is used."

It is through these thought-experiments that Wittgenstein attempts to get the reader to come to certain philosophical conclusions by him or herself, rather than being convinced by a succinct argument for those conclusions. This method of philosophy can be very effective and rewarding, however it makes it hard to provide philosophy students with a good understanding of Wittgenstein's philosophy without having them work through the book for themselves.

Natural language, meaning and use

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Wittgenstein's method leads to the common summary of Wittgenstein's argument in the Investigations: "Meaning just is use" — that is, we don't define words by reference to the objects or things which they designate in the external world nor by the thoughts, ideas or mental reprentations that we may associate with the, but by how they are used in effective, ordinary communication. For example, this means there is no need to postulate that there is something called good which exists independently of any particular "good deed." §77 This is one line of thought in the book, contrasting for example with Platonic realism and with Gottlob Frege's notions of sense and reference.

The Investigations deals largely with the difficulties of language and meaning. Wittgenstein viewed the tools of language as being fundamentally simple,§97 and he believed that philosophers had obscured this simplicity by misusing language and by the asking of meaningless questions. Wittgenstein attempted in Philosophical Investigations to make things clear, and 'shew the fly the way out of the fly-bottle'. §309

Meaning and definition

Over the course of the discussion, Wittgenstein rejects a variety of ways of thinking about what the meaning of a word is, or how meanings can be identified. He shows how, in each case, the meaning of the word presupposes our ability to use it.

Wittgenstein first asks the reader to perform a thought experiment: to come up with a definition of the word "game". §3 While this may at first seem a simple task, he then goes on to lead us through the problems with each of the possible definitions of the word "game". Any definition which focuses on amusement leaves us unsatisfied since the feelings experienced by a world class chess player are very different from those of a circle of children playing Duck Duck Goose. Any definition which focuses on competition will fail to explain the game of catch, or the game of solitaire. And a definition of the word "game" which focuses on rules will fall on similar difficulties.

The essential point of this exercise is often missed. Wittgenstein's point is not that it is impossible to define "game", but that we don't have a definition, and we don't need one because even without the definition, we use the word successful. Everybody understands what we mean when we talk about playing a game, and we can even clearly identify and correct inaccurate uses of the word, all without reference to any "definition".

Wittgenstein argues that 'definitions' emerge from what he termed 'forms of life', roughly the culture and society in which they are used. Wittgenstein stresses the social aspects of cognition. To see how language works, we have to see how it functions in a specific social situation. It is this emphasis on becoming attentive to the social backdrop against which language is rendered intelligible that explains Wittgenstein's elliptical comment that "If a lion could talk, we could not understand him." p.190

Wittgenstein rejects the idea that ostensive definitions can provide us with the meaning of a word. For Wittgenstein, the thing that the word stands for does not give the meaning of the word. Wittgenstein argues for this making a series of moves to show that to understand an ostensive definition presupposes an understanding of the way the word being defined is used. §26-34 So, for instance, there is no difference between pointing to a piece of paper, to its colour, or to its shape; but understanding the difference is crucial to using the paper in an ostensive definition of a shape or of a colour.

Family resemblances

Why is it that we are sure a particular activity -- Olympic target shooting -- is a game while a similar activity -- military sharp shooting -- is not? Wittgenstein's explanation is tied up with an important analogy. How do we recognize that two people we know are related to one another? We may see similar height, weight, eye color, hair, nose, mouth, patterns of speech, social or political views, mannerisms, body structure, last names, etc. If we see enough matches we say we've noticed a family resemblance. §66-§71 It is perhaps important to note that this is not always a conscious process -- generally we don't catalog various similarities until we reach a certain threshold, we just intuitively see the resemblances. Wittgenstein suggests that the same is true of language. We are all familiar (i.e. socially) with enough things which are games, and enough things which are not games so that we can categorize new activities intuitively.

This brings us back to Wittgenstein's reliance on indirect communication, and his reliance on thought-experiments. If many philosophers are confused, it is because they aren't able to see the family resemblances. They've made mistakes in understanding the vague intuitive rules language uses, and have thereby tied themselves up in philosophical knots. He suggests that an attempt to untangle these knots requires more than simple deductive arguments which point out the problems with their particular position. Instead Wittgenstein's larger goal seems to be to try to divert them from their philosophical problems long enough to indirectly re-train their intuitive ability to see the family resemblances.

Language games

Wittgenstein develops this discussion of games into the key notion of a language game. A language game is a way of using words. He introduces the term using simple examples, §7 but intends it to be used for the tremendous range of ways in which we use language. §23. In one game, a word might stand for things to be manipulated, but in another the same word might be used for asking questions or giving orders. "Water!" can be an exclamation, an order, a request or an answer to a question; which, depends on the language game in which it is being used. "Water" has no meaning apart from its use within a language game.

Rules

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One general characteristic of games that Wittgenstein considers in detail is the way in which they consist in following rules. "Rules" constitute a family, rather than a class that can be explicitly defined. §54 As a consequence, it is not possible to provide a definitive account of what it is to follow a rule. Indeed, he argues that any course of action can be made out to accord with a rule, and that therefore a rule cannot be used to explain an action. 201 Rather, that one is following a rule or not is to be decided by looking to see if the actions conform to the expectations in the particular form of life in which one is involved. Following a rule is a social activity.

Private language

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Wittgenstein also ponders the possibility of a language, the subject of which is only known the user; the usual example is that of a language in which one talks about ones sensations and other subjective experiences, and only to oneself. §243 Such an imaginary language he called a private language.

The possibility of such a language is intimately connected with a variety of other themes in his later works, especially his investigations of “meaning”. For Wittgenstein, there is no one, coherent “simple” or “object” that we can call “meaning”. Rather, the supposition that there are such things this is the source of many philosophical confusions. Meaning is a complicated phenomenon that is woven into the fabric of our lives. A good first approximation of what he is up to is that meaning is a social event; meaning happens between language users. As a consequence, it makes little sense to talk about a private language, with words that mean something in the absence of other users of the language.

Wittgenstein presents several perspectives on the topic. He discusses pain in some detail, making the somewhat surprising observation that one does not know that one is in pain. §246 Whereas others can learn of my pain, I cannot; rather, I simply have my own pain. For Wittgenstein, this is a grammatical point, part of the way in which the language game of "pain" is played. §248

But the core discussion centres on how one could possibly use the words of a private language. §256 &c.. He invites us to consider a the case in which someone decides that, each time they have a particular sensation, they will place a sign S in their diary. He points out that in such a case, we could have no criteria for the correctness of our use of S. Again, several examples are considered; one is that perhaps using S involves mentally consulting a table of sensations, to check that we have associated S correctly; but in this case, how could the mental table be checked for its correctness? "As if someone were to buy several copies of the morning paper to assure himself that what it said was true", as Wittgenstein puts it. §265.

Often, what is widely regarded as a deep philosophical problem will vanish, eventually being seen as a confusion about the significance of the words that philosophers use to frame such problems and questions. It is in this way that it is interesting to talk about something like a “private language” - it is helpful to see how the “problem” results from a misunderstanding.

Wittgenstein's beetle

Wittgenstein argues that if we can talk about something, then it is not private, in the sense considered here. But conversely, if we consider something to be indeed private, it follows that we cannot talk about it.

Wittgenstein discusses this using another thought experiment. §293 He asks us to imagine that each of us has a box, inside which is a beetle. No one can look inside anther's box, and each claims to know what a beetle is only by examining their own. Wittgenstein suggests that in such a situation, the word "beetle" could not be the name of a thing, since each of us might have something completely different in our box; the beetle "drops out of consideration as irrelevant".

Kripke's account

The discussion of private languages was revitalised from 1982 with the publication of Saul Kripke's book Wittgenstein on Rules and Private Language. Kripke, Saul. Wittgenstein on Rules and Private Language. Basil Blackwell Publishing, 1982. In this work Kripke developed from Wittgenstein's text an argument for scepticism towards rules, and hence towards meaning. Kripke's account, although philosophically interesting on its own merit, has been facetiously called Kripkenstein.

Seeing that and seeing as

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