Wittgenstein develops language games in order to prove his idea that there are no general fixed rules that apply to all of language. In examining a series of related language games—a technique he exploits most notably in the first part of the Brown Book— Wittgenstein demonstrates the different uses of different words in different contexts. For instance, in discussing a language that contains only the names of building materials and numbers, he highlights the fact that words for objects and wor ds for numbers are radically different, both in the way they are learned and the way they are used. Wittgenstein runs through a series of different language games that we can play with the word "comparing" (he applies a similar method to a wide range of o ther words), showing that there is no common feature between all these different uses of "comparing."
Most philosophical methods are geared toward making general statements of one kind or another. Wittgenstein develops a new method in language games so that he can demonstrate the dangers of hasty generalization. Language games produce a wide variety of in sights, all of which suggest the richness and diversity of language use.
The idea of family resemblance is Wittgenstein's answer to the idea of fixity of meaning. We tend to think of words as labels that we can apply to things, ideas, mental states, and so on. This leads to the notion that a word like "understanding" must have one fixed meaning, which we might identify as some sort of mental state or process. When we use the word "understanding" in different contexts, we think that both uses of the word share something in common.
In order to show the error in this way of thinking, Wittgenstein uses the metaphor of family resemblance. If we gather together five members of the same family, they probably look alike, although there is no distinctive feature that they all share in comm on. A brother and a sister might have the same dark eyes, while that sister and her father share a slightly turned-up nose. They have a group of shared features, some of which are more distinctly present in some members of the family, while some features are not present at all. Wittgenstein argues that the different uses of one word share the same family resemblance. There is no single defining characteristic of all uses of the word "understanding"; rather, these uses share a kind of family resemblance w ith one another.
Any kind of general behavior is likely in accordance with a rule. For instance, I can turn collections of written signs into sounds because I know the rule provided by the alphabet for converting written signs into sounds. There is no limit to how high I can count because I know the rule according to which successive numbers are generated. In this respect, all our behavior beyond individual, isolated actions, involves rule following. Wittgenstein was the first thinker to recognize the philosophical signif icance of this idea.
I can turn written signs into sounds because I know the rule of the alphabet. But how do I know how to follow the rule of the alphabet? For instance, if there is a table corresponding each letter to a sound, how do I know how to read that table? We need a further rule on how to read tables. And then we likely need another rule to interpret that second rule.
Wittgenstein shows us that there is nothing about rules in themselves that justify our general behavior. We cannot simply point to a rule as an explanation, because that rule needs justification just as the initial general behavior does. Wittgenstein conc ludes that there is no ultimate justification for our behavior.
Particularly in the Blue Book, Wittgenstein identifies analogy as a great source of philosophical confusion. For instance, because "A has a gold tooth" and "A has a toothache" have a similar grammatical form, we are tempted to draw an analogy between the two sentences and talk about toothaches and gold teeth as if they are similar. We might think that the way in which we cannot know that A has a toothache is similar to the way in which we cannot know that A has a gold tooth. We might think that we cannot see A's toothache in exactly the same way that we cannot see A's gold tooth when A's mouth is shut. We are wrong to think of toothaches and gold teeth as similar, however, because they are fundamentally different. Unlike gold teeth, toothaches are not the kind of thing that we can talk about seeing or not seeing.
Wittgenstein is careful to point out that there is nothing wrong with these analogies in themselves. The fault is not with ordinary language but with the philosophical misconceptions we generate from ordinary language. It is fine to talk about having a go ld tooth and having a toothache in the way that we do; however, we be vigilant about recognizing that an analogy in phrasing does not signify an analogy in meaning.
Philosophical confusion often arises when we mistake grammatical impossibility for physical impossibility. Take the grammatically similar sentences "A has a gold tooth" and "A has a toothache." We may not see the gold tooth because it is physically imposs ible to see it (when the mouth in question is shut), whereas it is grammatically impossible to feel A's toothache. Because in both cases we can say, "It is impossible to " we may think that the impossibility is the same in both cases. However, in the case of a toothache, the impossibility is not simply a matter of circumstances that happen to prevent us from seeing. It is the grammatical impossible to talk logically about feeling other people's toothaches. The point is that there is not an experience called "feeling A's toothache" that is possible.
We frequently talk about meaning, understanding, and believing as mental states, processes, or mechanisms. Wittgenstein argues that any such appeal to mental phenomena is simply an attempt to give an occult explanation of something we have trouble graspin g. In saying something is a mental mechanism, we free ourselves from the responsibility of giving a clear account of how that mechanism works, as we would have to do in order to explain physical mechanisms.
Wittgenstein shows us the faultiness of this conception in a number of ways, including using language games to show that there is no one distinct process that characterizes all cases of meaning, understanding, and believing. He also runs through a number of thought experiments that break down the distinction between inner and outer. If understanding a rule is simply a matter of having that rule appear before one's mind, then this understanding should be able to consist of having that rule appear before on e's eyes—say, written on a piece of paper. There is nothing about this mentalistic conception of how we understand rules that makes this mental process somehow distinct from, and more useful than, a physical process.