The sociology of knowledge is the study of the relationship between human thought and the social context within which it arises, and of the effects prevailing ideas have on societies. It is not a specialized area of sociology but instead deals with broad fundamental questions about the extent and limits of social influences on individuals' lives and the social-cultural basics of our knowledge about the world. Complementary to the sociology of knowledge is the sociology of ignorance, including the study of nescience, ignorance, knowledge gaps, or non-knowledge as inherent features of knowledge making.
The sociology of knowledge was pioneered primarily by the sociologist Émile Durkheim at beginning of the 20th century. His work deals directly with how conceptual thought, language, and logic could be influenced by the sociological milieu out of which they arise. In an early work co-written with Marcel Mauss, Primitive Classification, Durkheim and Mauss take a study of "primitive" group mythology to argue that systems of classification are collectively based and that the divisions with these systems are derived from social categories. Later, Durkheim in The Elementary Forms of the Religious Life would elaborate his theory of knowledge, examining how language and the concepts and categories (such as space and time) used in logical thought have a sociological origin. While neither Durkheim, nor Mauss, specifically coined nor used the term 'sociology of knowledge', their work is an important first contribution to the field.
The specific term 'sociology of knowledge' is said to have been in widespread use since the 1920s, when a number of German-speaking sociologists, most notably Max Scheler and Karl Mannheim, wrote extensively on sociological aspects of knowledge. With the dominance of functionalism through the middle years of the 20th century, the sociology of knowledge tended to remain on the periphery of mainstream sociological thought. It was largely reinvented and applied much more closely to everyday life in the 1960s, particularly by Peter L. Berger and Thomas Luckmann in The Social Construction of Reality (1966) and is still central for methods dealing with qualitative understanding of human society (compare socially constructed reality). The 'genealogical' and 'archaeological' studies of Michel Foucault are of considerable contemporary influence.