The notion of “family resemblance” concepts seems to have particularly impressed itself on Wittgenstein in connection with historical and cultural categories. In describing, say, religions or ideologies, we find we cannot delineate them by giving clear, necessary, and sufficient conditions. The same applies to schools of thought such as “materialism,” or “idealism,” or “naturalism.” These labels are family resemblance concepts: we use them to refer to something that is many-faceted and historically evolving. When we try to locate Wittgenstein within existing philosophical traditions we need to remember that this exercise, too, will involve our using just such a variety of criss-crossing similarities, some general and some specific (PI, 66). We must not assume that a similarity in one respect will be accompanied by similarities in others, or that any inconsistency or defect in the comparison is necessarily indicated by this. The value of these comparisons is to be assessed pragmatically, by their power to illuminate the structural features of his difficult arguments.
THE IDEALIST READING
A particularly interesting example of such a cultural classification is involved in the thesis, argued and opposed in different ways by a number of writers, that Wittgenstein was an “idealist” (in the philosophical sense or senses of the word). For example, attempts have been made by Williams and by Lear, among others, to assimilate the later Wittgenstein to the Kantian tradition of transcendental idealism. They claim Wittgenstein's central concern was to exclude the possibility of skepticism. His aim, it is said, was to legitimate our basic understanding of the world by leaving us with no alternative to our own conceptual scheme. To call our rationality into question, or to challenge it by posing alternatives, results in our speaking overt or covert nonsense. Incoherence is the only alternative to our basic categories of thought, hence Wittgenstein's concern that philosophers leave everything as it is, constructing no theories, and engaging in no revisionary activity.
Others have seen quite different projects in his work, classifying him as naturalistic and relativistic. Strawson sees Wittgenstein as subscribing to a form of “social naturalism,” while Malcolm draws attention to the references to real or imagined cultural diversity in Wittgenstein's writings and offers this as evidence against the transcendental reading. Meredith Williams emphasizes the differences between Wittgenstein's contextualism, that is, his grounding of meaning in use and social practices, and Kant's transcendental arguments.