Political philosophy is the branch of philosophy that deals with fundamental questions about politics: the existence of the state, the extent of liberty, the pursuit of justice, the source of rights and the duties of citizens. One of the earliest political philosopher was Plato of Greece, whose Republic greatly influenced later political thought. Plato's student, Aristotle, further systematized the study of politics in philosophy and his principles were carried through the Middle Ages by the Scholastic philosophers such as Thomas Aquinas. In the Renaissance era, Machiavelli started the realist approach of political theory, which was also reflected in the writings of Thomas Hobbes. Another major turning point in political philosophy was the Enlightenment, where the foundation of modern liberal democracy was laid.
Classical political philosophy
Plato and Aristotle
The two main works of Plato's political philosophy are The Republic and The Laws. The Republic starts by asking what the meaning of justice is, and the participants in the dialogue discuss justice by analogy to a city: "let's first find out what sort of thing justice is in a city and afterwards look for it in the individual, observing the ways in which the smaller is similar to the larger" (368e-396a). The city imagined in the Republic is widely considered a utopia (or possibly a dystopia): rule by wise philosopher-kings, no family structure, and no private property. While some philosophers (Bertrand Russell and Karl Popper) find the illiberality of Plato's imagined city to be an illiberal dystopia or a blueprint for Communism, most scholarly opinion see it as a device used to illustrate the notion of justice.
Aristotle, a student of Plato, radically diverged from the approach of his teacher and criticized the unrealistic state of The Republic in his masterpiece on political philosophy, Politics. He analyzed city-states with his moral framework of teleology and saw state as the highest end of human organization, above family and others, and the most self-sufficient one. Aristotle provided depiction of three kinds of regimes --- monarchy, aristocracy, and polity, and the repsective degradation of the three, namely, tyranny, oligarchy, and democracy. Some views in Politics would be obsolete to modern standards, such as his defense of slavery and his justification on male domination over women.
Medieval political thought
Political philosophy during the period called "the Enlightenment" was marked by the repudiation of "divine rights" theory previously used to justify monarchical absolutism, the abandonment of Aristotelian principles of Scholastic philosophy, and emphasis on reason. This trend in political theory was accompanied by simultaneous scientific progress.
Social contract theory
A breakthrough in political philosophy during this era was the emergence of social contract theory of legitimacy of the state. An early proponent of the theory was British philosopher Thomas Hobbes, who thought that the generation of government was based on a "contract," or agreement between every man and every man to set up a government to maintain order and avoid chaos. John Locke changed the concept of social contract substantially and proposed inalienable natural rights of "life, liberty, and property." Jean-Jacques Rousseau and Immanuel Kant separately developed their own ideas on social contract and arrived at distinct conclusions on the political organization of mankind.
The Enlightenment concept of social contract was revived in the contemporary era by John Rawls, a philosopher of the Anglo-American analytic tradition, who was influenced by Kant and expounded his theory of "original position" and its relation to political justice. Another American analytic philosopher, Robert Nozick, produced his own ideas based on original position but drastically departed from Rawls' approach and, in fact, was a vehement critic of Rawls' conclusions. From similar premises, Rawls argued for a society governed by two principles: that of the maximum amount of liberty for the maximum number of people, and that of tolerating inequality only when the positions of inequality are distributed in a way that could be characterized as "equal opportunity" and the inequality benefits the worst off in society. Nozick, a political libertarian, argues from similarly liberal principles to a minimal "night watchman" state, which can use force to resolve disputes between citizens, but does not structure the inequalities and differences in society.
In recent decades, both the Enlightenment and Rawlsian forms of social contract theory have been contested for their failure to give due attention to problems of gender and racial justice as part of a more general communitarian critique.
Political turmoil and revival of conservatism
The political atmosphere during the Enlightenment saw its violent shakedown in the French Revolution and its Reign of Terror. This had led to a backlash against the previous philosophy of Enlightenment that sought to establish state with liberty and equality based on reason, and conservative theorists such as Edmund Burke of Britain and Joseph de Maistre of France gained prominence.
Contemporary political philosophy
Much of contemporary political philosophy is centered around the debate between liberalism and communitarianism - the interplay between the rights of individuals and the interests of societies and communities as a whole. The work of Charles Taylor, Michael Sandel and Alistair MacIntyre are the best representatives of contemporary philosophical communitarianism, with those inspired by John Rawls and Robert Nozick taking the side of liberalism.
- See the first of John Locke's Two Treatises on Government which attempts to refute the divine rights apologia of Robert Filmer.
- To illustrate: a doctor may be paid more than a street-sweeper, but only if the process by which one can become a doctor is an equal-opportunity process, and that paying doctors more helps the worst off in society.
- See especially Charles W. Mills, The Racial Contract (Ithaca, NY: Cornell University Press, 1999), Carole Pateman, The Sexual Contract (Stanford: Stanford University Press, 1988), and Carole Pateman and Charles Mills, Contract and Domination (Malden, MA: Polity Press, 2007).