The leviathan is the vast unity of the State. But how are unity, peace, and security to be attained? Hobbes’ answer is sovereignty, but the resurgence of interest today in Leviathan is due less to its answers than its methods: Hobbes sees politics as a science capable of the same axiomatic approach as geometry.

The English philosopher and physician John Locke (1632 - 1704) is widely regarded as one of the most influential of Enlightenment thinkers. His work had a significant effect on the development of epistemology and political philosophy. The Second Treatise on Civil Government places sovereignty in the hands of the people, as Locke's fundamental argument is that people are equal and invested with natural rights in a state of nature in which they live free from outside rule.

Immanuel Kant’s Critique of Pure Reason can lay claim to being the most important single work of modern philosophy, a work whose methodology, if not necessarily always its conclusions, has had a profound influence on almost all subsequent philosophical discourse. In this work Kant addresses, in a groundbreaking elucidation of the nature of reason, the age-old question of philosophy: “How do we know what we know?” and the limits of what it is that we can know with certainty.

Discourse on the Origin and Basis of Inequality Among Men by the philosopher Jean-Jacques Rousseau was originally written for an essay competition run by the Dijon Academy of Arts and Sciences in 1754. The question was, "What is the origin of inequality among men, and is it authorized by the natural law?" Rousseau's text is divided into four main parts: a dedication, preface, an extended inquiry into the nature of the individual, and another inquiry into the evolution of the human species within society.

Often considered the foundation of political liberalism, John Locke's Two Treatises of Government was first published anonymously in 1689, in the wake of England's Glorious Revolution. In The First Treatise of Government, Locke refutes the idea of divine monarchy, while The Second Treatise of Government articulates Locke's philosophy of government, which he based upon his theories of natural rights and the social contract.

First published in 1859, John Stuart Mill's On Liberty is an exhaustive exploration of social and civic liberty, its limits, and its consequences. Mill's work is a classic of political liberalism that contains a rational justification of the freedom of the individual in opposition to the claims of the state.

In 1831, Alexis de Tocqueville, a young French aristocrat and civil servant, made a nine-month journey through the eastern United States. The result was Democracy in America, a monumental study of the strengths and weaknesses of the nation’s evolving politics. His insightful work has become one of the most influential political texts ever written on America.

The foundation for all modern economic thought and political economy, The Wealth of Nations is the magnum opus of Scottish economist Adam Smith, who introduces the world to the very idea of economics and capitalism in the modern sense of the words.

The title Politics literally means ‘the things concerning the city’. Here, Aristotle considers the important role that politics plays in the life of the community and its contribution to harmonious and virtuous existence. It is divided into eight books and was a cornerstone in political philosophy for centuries despite certain features - including attitudes towards slaves and women - clearly placing its conclusions and advice within the confines of Athenian society of the fourth century BCE.

Plagued by spiritual anguish, devout everyman Christian fears his fate in the sinful City of Destruction. He’s told that only by embarking for the Celestial City can he achieve personal salvation. After his wife and children refuse to join him, he sets forth alone into the unknown. Mocked for his faith, tempted at every turn, and heartened by fellow pilgrims, Christian’s winding journey toward grace unfolds. But as he reaches Mount Zion, his family chooses to follow the same treacherous path, hoping to join Christian in the shining light.

In On the Genealogy of Morals, subtitled "A Polemic", Nietzsche furthers his pursuit of a clarity that is less tainted by imposed prejudices. He looks at the way attitudes towards 'morality' evolved and the way congenital ideas of morality were heavily colored by the Judaic and Christian traditions.

The Republic poses questions that endure: What is justice? What form of community fosters the best possible life for human beings? What is the nature and destiny of the soul? What form of education provides the best leaders for a good republic? What are the various forms of poetry and the other arts, and which ones should be fostered and which ones should be discouraged? How does knowing differ from believing?

From the moment of its publication in 1748, The Spirit of the Laws proved to be a controversial work provoking widespread interest. Within three years it had been translated into various European languages - and was swiftly added to the List of Prohibited Books by the Roman Catholic Church. It is a remarkable book, a potpourri of observations and comments ranging far and wide over the social activities of mankind and it exerted a great influence on political leaders in the following decades.

Plagued with doubt and uncertainty in sensory knowledge, Descartes is struck with the idea that everything he knows is false. He considers the possibility that he has been deceived by an 'evil demon' and is left with nothing to lean on, until he arrives at the phrase 'cogito ergo sum' ('I think, therefore I am'). Among the most quoted philosophical works in history, Meditations on First Philosophy and Discourse on the Method together display the full workings of Descartes' skeptical method and the formation of his famous phrase.

Originally published anonymously, The Federalist Papers first appeared in 1787 as a series of letters to New York newspapers exhorting voters to ratify the proposed Constitution of the United States. Still hotly debated and open to often controversial interpretations, the arguments first presented here by three of America's greatest patriots and political theorists were created during a critical moment in our nation's history.