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.

Born out of the political turmoil of the English Civil War, Leviathan stands out as one of the most in influential political and philosophical texts of the 17th century. It argues for the restoration of the monarchy in light of the republic and calls for a commonwealth ruled by an authoritative, autocratic figure with absolute sovereignty. This would put an end to all controversy, war, and fear and establish peace via social contract.

After more than 2,300 years, the Greek philosopher Aristotle still remains one of the most influential thinkers who has ever lived. There was hardly any field of human knowledge in existence during his day in which he did not make a major contribution. Additionally, he probed areas which were never before examined. Indeed, one could make the claim that no individual person has ever known as much about this world as Aristotle. His analyses of zoology and logic paved the way for modern forensic techniques, and for which every scientist down to this day owes him a debt of gratitude.

What is life? What is my place in it? What choices do these questions obligate me to make? More than a half-century after it burst upon the intellectual scene - with roots that extend to the mid-19th century - Existentialism's quest to answer these most fundamental questions of individual responsibility, morality, and personal freedom, life has continued to exert a profound attraction.

As intriguing today as when it was first published, Hume's An Enquiry Concerning Human Understanding is a fascinating exploration into the nature of human knowledge. Using billiard balls, candles, and other colorful examples, Hume conveys the core of his empiricism - that true knowledge can be gained only through sensory experience.

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?

Rene Descartes is often described as the first modern philosopher, but much of the content of his Meditations on First Philosophy can be found in the medieval period that had already existed for more than a thousand years. Does God exist? If so, what is his nature? Is the human soul immortal? How does it differ from the body? What role do sense experience and pure reason play in knowing?

Aristotle's most complicated and academic work. This is a challenging work for even those who admire his other seven books. Incomparable analysis in language and thought, with a clear, succinct prose touch.

The Fable of the Bees—a satirical poem, prose discussion, three essays and six dialogues completed in 1729—exposes human vices but defends them as a necessity within a wealthy society. Mandeville’s bees thrive until they start living by honesty and virtue… then they are impoverished. Mandeville did not play by the rules: he satirized the sins of society but also ridiculed the widespread hypocrisy of deploring these sins whilst reaping their benefits. He and his work were attacked for the rest of the century.

Benedict de Spinoza's Ethics, first published in 1677, constitutes a major systematic critique of the traditional and religious foundations of philosophical thought. In it, Spinoza follows a logical step-by-step format consisting of definitions, axioms, propositions, proofs, and corollaries to create a comprehensive inquiry into the truth about God, nature, and humans' place within the universe. From these broad metaphysical themes, Spinoza derives what he considered to be the highest principles of religion and society and lays out an ethical system in which reason is the supreme value.

Aristotle's Nicomachean Ethics, said to be dedicated to Aristotle's son, Nicomachus, is widely regarded as one of the most important works in the history of Western philosophy. Addressing the question of how men should best live, Aristotle's treatise is not a mere philosophical meditation on the subject, but a practical examination that aims to provide a guide for living out its recommendations.

Composed in four parts between 1883 and 1885, Thus Spoke Zarathustra is the most famous and influential work of German philosopher Friedrich Nietzsche. The work is a philosophical novel in which the character of Zarathustra, a religious prophet-like figure, delivers a series of lessons and sermons in a Biblical style that articulate the central ideas of Nietzsche's mature thought.

Two years before he died, St. Thomas Aquinas, probably the greatest teacher the Church has ever known, was asked by his assistant Brother Reginald to write a simple summary of the faith of the Catholic Church for those who lacked the time or the stamina to tackle his massive Summa Theologica. In response, the great saint quickly set down in language that non-scholars can understand his peerless insights into the major topics of theology: the Trinity, Divine Providence, the Incarnation of Christ, the Last Judgment, and much more.

A caustic criticism of nearly every philosophic predecessor and a challenge of traditionally held views on right and wrong, Friedrich Nietzsche’s Beyond Good and Evil paved the way for modern philosophical thought. Through nearly three hundred transformative aphorisms, Nietzsche presents a worldview in which neither truth nor morality are absolutes, and where good and evil are not opposites but counterparts that stem from the same desires.

Historians universally agree that Thucydides was the greatest historian who has ever lived, and that his story of the Peloponnesian conflict is a marvel of forensic science and fine literature. That such a triumph of intellectual accomplishment was created at the end of the fifth century B.C. in Greece is, perhaps, not so surprising, given the number of original geniuses we find in that period. But that such an historical work would also be simultaneously acknowledged as a work of great literature and a penetrating ethical evaluation of humanity is one of the miracles of ancient history.