We are often tempted to think that language is fundamentally a relationship between names and objects. The danger is that we may conclude that the name–object relationship is the fundamental link that connects language to the world. In fact, names of objects can only be identified as such when we contrast them with other kinds of words, such as words for colors, prepositions, numbers, and the like. The supposedly fundamental relation between names and objects only makes sense within the broader context of language and cannot be abstracted from it. The meaning of words is not determined by an abstract link between language and reality but by how words are used.
By talking about meaning in the abstract, we are tempted to think of the meanings of words as fixed, with definite limits. However, the meanings of words are often vague and fluid without their being any less useful as a result. Wittgenstein takes the example of game, showing that there is no rigid definition that includes everything we consider a game and excludes everything we do not consider a game, but we nevertheless have no difficulty in using the word game correctly. As far as Wittgenstein is concerned, ordinary language is perfectly adequate as it is. His aim is not to show the underlying structure of language but rather to show that all attempts at digging beneath the surface of language lead to unwarranted theorizing and generalization.
One of Wittgenstein’s primary targets in the Philosophical Investigations is the language of psychology. We are tempted to think that words like understanding, meaning, thinking, intending, and the like denote mental states or processes. Wittgenstein conducts what he calls a “grammatical investigation,” looking closely at the way these words are used to show that the criteria we use for judging whether someone has, for example, understood how to play chess have nothing to do with that person’s mental state and everything to do with that person’s behavior. That is not to label Wittgenstein as a behaviorist: he is trying to show the inevitable flaws in any theory of the mind, not to set up an alternative theory of his own.
Our language and customs are fixed not by laws so much as by what Wittgenstein calls “forms of life,” referring to the social contexts in which language is used. In other words, the most fundamental aspect of language is that we learn how to use it in social contexts, which is the reason why we all understand each other. We do not understand each other because of a relationship between language and reality. Wittgenstein gives the example of a student who obeys the rule “add 2” by writing 1004 after 1000 and insisting that this is a correct application of the rule. In such an instance, there is nothing we can say or do to persuade the student otherwise because the misunderstanding lies at a deeper level than explanation can reach. Such examples do not occur in ordinary life not because there is some perfectly unambiguous explanation for “add 2” but because we share forms of life: people, on the whole, simply understand one another, and if this basic understanding were missing, communication would be impossible.
Elaborating on his view that language functions according to shared norms and forms of life, Wittgenstein denies the possibility of a private language. That is, it is inconceivable that someone could invent a language for his or her own private use that describes his or her inner sensations. In such a language, there would be no criteria to determine whether a word had been used correctly, so the language would have no meaning. Wittgenstein illustrates this point by arguing that the sentence, “I know I am in pain” makes no sense. The claim to know something carries with it further baggage that is inapplicable when talking about our own sensations. To claim to know something, we must also be able to doubt it, we must have criteria for establishing our knowledge, there must be ways other people can find out, and so on—all of which is absent when dealing with our inner sensations.
The last 300 sections of part I, as well as part II, of the Investigations deal with a number of related issues but lack a general thrust. Wittgenstein attacks the idea that we have privileged knowledge of our own mental states, suggesting that our relation to our mental states is not one of knowledge at all. This suggestion diminishes the thrust of “other minds skepticism,” the philosophical claim that we have only imperfect knowledge of other minds, which is based on the premise that the subject is the only one with privileged knowledge of his or her own mind. Part II deals primarily with the grammar of the word see, discussing, among other things, the distinction between see and see as. We do not see a fork as a fork: we simply see the fork. The word as implies an act of interpretation, and we do not interpret what we see except in those cases where we really do entertain more than one possible interpretation.