Unlike Noam Chomsky’s ambitious recent work in linguistics, Steven Pinker’s Words and Rules is a popular exposition of scholarly work on language. It succeeds in its aim of conveying a great deal of information in a lively and often humorous style. The book has a simple thesis, often repeated:
The ingredients of language are words and rules. Words in the sense of memorized links between sound and meaning; rules in the sense of operations that assemble words into combinations whose meaning can be computed from the meanings of the words and the way they are arranged.
If we assume that “computed” in the quoted passage just means “figured out,” then there is a way of interpreting the thesis in which it could hardly be false, and indeed would not be worth writing a book about. We cannot imagine a full-blown spoken human language that did not have both words and rules in Pinker’s rather special senses—that is, that did not have both meaningful spoken units and ways of combining them into larger units such as sentences. Clearly you need both. Words without rules are blind, rules without words are empty.
According to another interpretation the thesis is false. Pinker sometimes talks as if words and rules are sufficient to understand sentences. But that is wrong. We understand the word “cut” in the order “Cut the grass” quite differently from the way we understand “cut” in the order “Cut the cake” even though the same word, in his sense, occurs in both. Thus we understand “cut” in the sentences “The barber cut my hair,” “The tailor cut the cloth,” and “The surgeon cut the skin” quite differently because we bring to bear on these sentences a large cultural background knowledge of how things work and how they are done. For the same reason we don’t know how to interpret the sentences “Sally cut the sun” or “Bill cut the mountain” because we have no background knowledge that would determine an interpretation for these sentences.
Notice that in the sentences we do not understand, we have perfectly ordinary words in perfectly ordinary com-binations, but we still have no idea how to interpret the sentences. The point applies throughout our use of language. We understand the same word “healthy” differently in “healthy complexion,” “healthy diet,” and “healthy body” even though the word keeps the same meaning. The point is one that Pinker seems to have missed: the understanding of any sentence requires a set of capacities that go beyond words and rules in his senses of these notions. In any case, whether we interpret his claim as platitudinous or false, he uses it as an entering wedge into a number of important arguments, as we will see.
One quibble about the title Words and Rules, and the formulation of the thesis: it is misleading for Pinker to treat words and rules as if they were somehow contrasting, because words are also a matter of rules. To know …