Focusing on the methodological principles which underlie sociologists' study of social reality, this text offers clarification and outlines how the different approaches to study originate from various methodogical and philosophical traditions.

Positivism as a theory of science - Comte, Popper, summary; positivism in sociology - the definition of sociological knowledge, the logic of sociological investigation, methods of observation, the practical utility of sociological knowledge, summary; Marxist realism as a theory of science - Keats argument, summary; Marxist realism in sociology - the definition of sociological knowledge, the logic of scientific investigation, methods of investigation, the practical utility of sociological knowledge; Marxist non-realism as a theory of science - Habermas' arguments, summary; Marxist non-realism in sociology - the definition of sociological knowledge, the logic of scientific discovery, a non-realist view of "methods" in sociology, the practical utility of sociological theorizing, summary; summary of the debate.