CHAPTER I
MEANING
§ 1. The three tasks of epistemology
Every theory of knowledge must start from knowledge as a given sociological fact. The system of knowledge as it has been built by generations of thinkers, the methods of acquiring knowledge used in former times or used in our day, the aims of knowledge as they are expressed by the procedure of scientific inquiry, the language in which knowledge is expressed—all are given to us in the same way as any other sociological fact, such as social customs or religious habits or political institutions. The basis available for the philosopher does not differ from the basis of the sociologist or psychologist; this follows from the fact that, if knowledge were not incorporated in books and speeches and human actions, we never would know it. Knowledge, therefore, is a very concrete thing; and the examination into its properties means studying the features of a sociological phenomenon.
We shall call the first task of epistemology its descriptive task—the task of giving a description of knowledge as it really is. It follows, then, that epistemology in this respect forms a part of sociology. But it is only a special group of questions concerning the sociological phenomenon “knowledge” which constitutes the domain of epistemology. There are such questions as “What is the meaning of the concepts used in knowledge?” “What are the presuppositions contained in the method of science?” “How do we know whether a sentence is true, and do we know that at all?” and many others; and although, indeed,
