This paper presents an analysis of the structure of contemporary sociological knowledge in terms of a theory of scientific discourse. The concept of 'discourse' is introduced as a theoretical refinement of the concept of 'paradigm' and is applied to the classes of knowledge claims of the natural and social sciences. It is concluded that general modes of scientific discourse are definable in terms of their vertical differentiation from everyday discourse, while particular modes of sociological discourse are additionally definable in terms (...) of their horizontal differentiation. A classification is then proposed which identifies three modes of sociological discourse: natural, technical and formal. (shrink)