This document provides an overview of five major classical sociological theorists: Auguste Comte, Herbert Spencer, Karl Marx, Emile Durkheim, and Max Weber. It summarizes their key ideas and contributions to sociology. Auguste Comte developed the idea of positivism and described society progressing through theological, metaphysical, and positive scientific stages. Herbert Spencer applied evolutionary theory to society and believed societies evolve toward greater complexity. Karl Marx analyzed society through historical materialism and the conflict between social classes. Emile Durkheim studied how social forces like division of labor influenced suicide rates. Max Weber examined the relationship between Protestantism and the emergence of capitalism.