A number of Western political theorists and philosophers, including Plato, Polybius, Machiavelli, Vico, Hobbes, Locke, Montesquieu, and Rousseau, have treated political problems in a broader social context. Thus Montesquieu regarded the political forms of different states as a consequence of the working of deep underlying climatic, geographic, economic, and psychological factors. In the 18th cent., Scottish thinkers made inquiries into the nature of society; scholars like Adam Smith explored the economic causes of social organization and social change, while Adam Ferguson considered the noneconomic causes of social cohesion.

It was not until the 19th cent., however, when the concept of society was finally separated from that of the state, that sociology developed into an independent study. The term sociology was coined (1838) by Auguste Comte. He attempted to analyze all aspects of cultural, political, and economic life and to identify the unifying principles of society at each stage of human social development. Herbert Spencer applied the principles of Darwinian evolution to the development of human society in his popular and controversial Principles of Sociology (1876–96). An important stimulus to sociological thought came from the work of Karl Marx, who emphasized the economic basis of the organization of society and its division into classes and saw in the class struggle the main agent of social progress.

The founders of the modern study of sociology were Émile Durkheim and Max Weber. Durkheim pioneered in the use of empirical evidence and statistical material in the study of society. Weber's major contribution was as a theorist, and his generalizations about social organization and the relation of belief systems, including religion, to social action are still influential. He developed the use of the ideal type—a working model, based on the selective combination of certain elements of historical fact or current reality—as a tool of sociological analysis. In the United States the study of sociology was pioneered and developed by Lester Frank Ward and William Graham Sumner.

The most important theoretical sociology in the 20th cent. has moved in three directions: conflict theory, structural-functional theory, and symbolic interaction theory. Conflict theory draws heavily on the work of Karl Marx and emphasizes the role of conflict in explaining social change; prominent conflict theorists include Ralf Dahrendorf and C. Wright Mills. Structural-functional theory, developed by Talcott Parsons and advanced by Robert Merton, assumes that large social systems are characterized by homeostasis, or steady states. The theory is now often called conservative in its orientation. Symbolic interaction, begun by George Herbert Mead and further developed by Herbert Blumer and others, focuses on subjective perceptions or other symbolic processes of communication.