Political philosophy is the study of topics such as politics, liberty, justice, rights, law, the enforcement of legal code by authority, and what makes a government legitimate.
History[]

Western political philosophy originated in ancient Greece, dating back to (at least) Plato. The Greek city-states experimented with virtually every form of political organization mankind has ever conceived of. Plato grouped them into five broad categories: timocracy (rule by the wealthy), tyranny (rule by a single strongman), democracy (rule by the masses), oligarchy (rule by an elite), and aristocracy (rule by the nobility). Roman political philosophy was influenced by Stoicism and by Roman statesman Cicero. In the Christian era, Augustine of Hippo was influenced by Plato. Augustine ushered in a key change, moderating the theory of justice in the Roman world and emphasizing the state's obligation to provide mercy as a moral example. Augustine preached that a person is not a member of the city, either being a member of the City of God or the City of Man. In his work City of God, he attacked the Roman view on citizenship and argued that the ideal of the Christian life is something for the afterlife.
Thomism[]

800 years later, Thomas Aquinas developed his own theories. He saw Man as a social being who interacted with other members of the community, bringing up the point of division of labor. He made a distinction between the good man and the good citizen, developing the libertarian theory. Aquinas believed in monarchy, but he found as acceptable or decent any government, regardless of its formal organization, as long as it governed for the common good. He believed that oligarchy deteriorated easier than monarchy, and that the King's powers should be curbed to prevent him from becoming a tyrant. However, he also feared anarchy, and he supported the divine right of kings.
Modern era[]
Niccolo Machiavelli's The Prince did much to influence modern political thought in the West. A minority of interpreters viewed the book as a satire, meant to be given to the Medici after their recapture of Florence and Machiavelli's expulsion (he supported the republic instead of the Medici's oligarchy). Machiavelli viewed good and evil as means to an end, that being a secure and powerful state.
Thomas Hobbes expanded the view during the English Renaissance, believing in the inherent selfishness of the individual and the need to endorse a strong, central power as the only means of preventing the disintegration of the social order. John Locke, in particular, exemplified modern political theory, proposing a state of nature theory. He believed that the divine right of kings is a passing fancy, and he supported Aristotle's dictum that man seeks to be happy in a state of social harmony as a social animal, although he believed that Man's mind comes into the world as a blank sheet. According to Locke, the kind of absolute ruler presented by Hobbes was unnecessary.
In the 19th century, the Marxist critique of capitalism, liberalism, and fascism emerged. The Industrial Revolution produced this ideology, as urbanization and capitalism reshaped society. Socialism gained increasing popular support among the urban working class, and Karl Marx established principals that would be used by 20th century revolutionaries such as Vladimir Lenin, Mao Zedong, and Fidel Castro. His theory of revolution towards the common good was partly based on Immanuel Kant's view of history, turning Georg Wilhelm Friedrich Hegel's dialectic "right-side-up" again. In addition, anarchism and syndicalism gained prominence.
The October Revolution of 1917 brought communism onto the world stage; at the same time, the introduction of universal suffrage led to social democratic parties taking power. In the mid-20th century, the "Austrian School" identified socialists and fascists as being different kinds of political totalitarianism, arguing that they were flipped sides of the same coin.
An important contributor to the development of libertarianism was Ayn Rand, who emphasized individual rights such as property rights and laissez-faire capitalism; she believed that the latter was the only system based on the protection of individual rights. Although her views were often classified as "conservative" or "libertarian", she preferred the term "radical for capitalism". She worked with conservatives on political projects, but disagreed with them on religion and ethics. She even denounced libertarianism, which she associated with anarchism, a "naive theory based on subjectivism that could only lead to collectivism in practice". Her philosophical system was Objectivism. The publication of John Rawls, A Theory of Justice (1971), argued that, from an original position, we would choose the same liberties for everyone, and that we would incentivize economic well-being for all in society.
Justification of the state[]
The justification of the state refers to the source of legitimate authority for the state or government. Typically, such justification explains exist why the state should exist at all, and its powers. There is no single, universally accepted answer, with anarchists believing that there is no justification whatsoever.
In medieval Europe, the divine right of kings was the main justification of the state, with legitimacy of the state's lands being derived from the idea that the monarch personally possessed those lands. In the nation-states of the early modern period, monrachies were hereditary, although the Holy Roman Empire's rulers were elected. Political ideas in China at the time advocated for the "Mandate of Heaven", placing the ruler in the divine position of being the link between Heaven and Earth. However, the state was a permanent one, and it did not emphasize a certain dynasty's rule; the Mandate of Heaven laid only with the ruler who governed well.
During the Enlightenment, a new justification of the state developed. Jean-Jacques Rousseau developed the "Social Contract", believing that the legitimacy of the government came from the people. Under this theory, no person should have absolute power, and the perfect state meets the needs and wishes of its citizens. The contract also requires that the individual give up some of his natural rights to maintain social order through the rule of law. Modern democracy was born out of this theory.
The "Public Goods" theory was an example of the theoretical thinking shifting the emphasis on faith and sovereignty to socioeconomic logic, as Marx did. The state was legitimized by its obligations for the redistribution and provision of public goods.
Anarchism claims that the community of those fighting to create a new society must themselves be stateless, while communism seeks to replace communal divisions with a universal community once the divisions could be replaced. State socialism states that the degree to which a state has a working class is the degree to which it fights government, class, work and rule. To the degree that it wins such a fight is held to the degree of whether it is communist, capitalist, or socialist. Anarcho-capitalism argues that taxes are theft, that the government and the business community are complicit in governance, and that it is similar to organized crime. Anarcho-communism says that taxes, being theft, are also property, which is also theft, and that those fighting against capitalism and the state to produce a communist society must themselves form such a society.
The majority of viewpoints agree that some kind of government is morally justified. There are several ways to conceive of the differences between the political views, such as in what areas the government has jurisdiction, its ability to intervene, and what constitutes intervention. Marxists argue that private property exists only through the government, contrary to philosophers such as Aquinas and Locke, who maintained that property rights are prior to government.