This textbook analyses the work of classical and contemporary sociological theorists. The first part is dedicated to Comte, Spencer, Marx, Durkheim, Weber, Pareto, and Simmel. The second part covers the major contemporary sociological perspectives: Functionalism, Marxism, Conflict Theory, Symbolic Interactionism, Phenomenological Sociology, and Rational Choice Theory. The third part is devoted to Postmodern Theory, Feminist Theory, Postcolonial Theory, and Race Theory. The author combines academic rigour with clear and accessible language, offering students an in-depth and extensive overview of the main, recurring problems that have troubled sociological theory from its origins to the present day. The textbook uses contemporary examples, analysing how sociological theory can explain the most tragic phenomena of our time, including the war in Ukraine, the Israeli-Palestinian conflict, US-China competition over Taiwan, nuclear proliferation, radicalization, neofascism, white suprematism, jihadism, and terrorism. With pedagogic features aiding learning, this book helps navigate the various approaches, methods, and research that divide sociologists into distinct schools. This textbook is therefore an invaluable tool to any sociology student looking to gain a comprehensive understanding of the foundational thinkers that have shaped the discipline.