This book is concerned with the relationship between classifications of and theoretical explanations of social relations. The general thesis presented here is that forms of classification are not and cannot be independent of forms of theoretical explanation. The reason for this dependence is that the very objects to be classified are constituted by definite social theories and these theories also provide the conceptual means of classification. The objects classified are not given independently of theory-categories of classification such as traditional society/industrial society or religion/magic are products of specific forms of theory.