Thesis advisor: Nasser Behnegar / Political ideology can be described in terms of value pluralist theory. Much of the variation between political ideologies can be explained by the fact that the principles that are essential to society--liberty, equality, fraternity, peace, loyalty, and civilization--are incommensurable and often conflict forcing each person and community to emphasize some principles over others leading to an imperfect society. Each political ideology is a combination of interests and the selected balance of principles and thus can be essentially defined according to the level of preference for each of these six principles. This paper studies major political ideologies throughout the globe and develops a model for understanding them in these terms. This paper further argues for a pluralist democracy, with constantly shifting ideological dominance in a community as the next best thing to an impossible utopia and the only means of preventing the collapse of society due to a lack of essential principles. This model makes clear the fallacy of understanding political ideology in terms of "left" and "right," which not only oversimplify political ideology but also fundamentally misrepresent it. It also leads to narrowing visions of politics that prevent significant changes to a political system and undermine the possibility for pluralist democracy. / Thesis (MA) — Boston College, 2012. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Political Science.