- The Sociological approach to political science studies politics in the context of society and social groups. G. Catlin is associated with different aspects of political science, often focusing on power, but the sociological approach is a recognized method. - The Philosophical approach deals with normative questions about politics (what should be). Leo Strauss is a prominent figure in political philosophy. - The Historical approach analyzes political events and institutions through history. John Rawls is a major contemporary political philosopher known for his theory of justice ('A Theory of Justice'), which is primarily philosophical and theoretical, not historical in its methodology. - The Integrated approach combines various methods like historical, sociological, and legal analysis. Carl J. Friedrich is known for his comprehensive studies that often blend different approaches.