Perhaps one of the most revolutionary works of philosophy ever presented, The Phenomenology of Spirit is Hegel's 1807 work that is in numerous ways extraordinary. A myriad of topics are discussed, and explained in such a harmoniously complex way that the method has been termed Hegelian dialectic. Ultimately, the work as a whole is a remarkable study of the mind's growth from its direct awareness to scientific philosophy, proving to be a difficult yet highly influential and enduring work.

More than two centuries after its initial publication in 1781, Immanuel Kant's Critique of Pure Reason remains perhaps the most influential text in modern philosophy. Kant himself claimed his work as a revolutionary document and insisted that it changed the discipline of philosophy as thoroughly as Copernicus had changed astronomy 300 years earlier, when he said the Earth revolved around the sun and not the other way round.

First published in 1651, Leviathan drove important discussions about where kings get their authority to rule and what those kings must, in turn, do for their people. This is known as the "social contract". Thomas Hobbes wrote the book while exiled from his native England following the English Civil War that unseated King Charles I. In the face of England's radical - if temporary - rejection of its monarchy, Hobbes wanted to explain why it was important to have a strong central government, which in his time meant having a sovereign at its head.

Hegel is regarded as one of the most influential figures on modern political and intellectual development. After painting Hegel's life and times in broad strokes, Peter Singer goes on to tackle some of the more challenging aspects of Hegel's philosophy. Offering a broad discussion of Hegel's ideas and an account of his major works, Singer explains what have often been considered abstruse and obscure ideas in a clear and inviting manner.

In five hours, Andy will take you through Hegel’s Logic, the book on philosophy which has been most influential amongst radicals and revolutionaries and all those who stray from the well trodden path of conventional, bourgeois thinking. The book begins with an explanation of social conditions in early 19th-century Germany and then, walks through the text of the Logic paragraph by paragraph. This reading stands out from all others in its clarity of explanation and in Andy's ability to make Hegel's Logic relevant to social and political problems of today.

In her 1958 work, political theorist Hannah Arendt asks two fundamental questions: "Under what conditions do politics emerge?" and "Under what conditions can politics be eliminated?" In searching for answers she turns some long-established thinking on its head. Ancient political philosophers such as Plato and Aristotle believed that a life spent thinking was more important than an active life of labor, work, and action. But Arendt argues that political action is every bit as important as political thinking.

What might society look like if we were brave enough to emerge fully from the shadow of the Christian God? The German philosopher Friedrich Nietzsche explores this intriguing question in his 1886 work, Beyond Good and Evil. Going further, Nietzsche then asks of his "philosophers of the future" that they take on the challenge of supplying humanity with new ideals to live by.

Kenneth Waltz's Theory of International Politics created a "scientific revolution" in international relations, starting two major debates. In the 1980s it defined the controversy between the neorealists, who believed that competition between states was inevitable, and the neoliberals, who believed that states could cooperate with each other. As the debate wound down with the end of the Cold War in the 1990s, a second more fundamental debate began.

Geneva-born thinker Jean-Jacques Rousseau's famous work of political philosophy from 1762 is based on a give-and-take theory of the relation between individual freedom and social order: the social contract that gives the work its name. Rousseau thinks about the issue by starting with what is known as the state of nature, a lawless condition where people are free to do what they like, governed only by their own instinctive sense of justice. People are free, but they are also vulnerable to chaos.

Its arguments would go on to shape global economics and influence world leaders in the late 20th century, but Capitalism and Freedom was largely ignored when it was first published in 1962. The first work written for the general public by American economist Milton Friedman, the book argues that a free market with little government interference is the best way to run society.

More than 200 years after Adam Smith published The Wealth of Nations, governments around the world continue to address many of the issues discussed in the book. The most powerful states in the world are still committed to international trade, but questions are repeatedly asked about the role of governments in the economy and the effectiveness of the free market.

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.

Austrian-born economist Friedrich Hayek's 1944 work, The Road to Serfdom, analyzes the ways in which excessive government planning can erode democracy. Published while World War II still raged, the work draws influential parallels between the totalitarianism of both socialism and Nazism and increasing control exerted by Western democracies.

In Philosophical Investigations, the Austrian philosopher Ludwig Wittgenstein presents a radical approach to problems in the philosophy of language and the philosophy of mind. In fact, he sets out a radically new conception of philosophy itself. Published in 1953, two years after Wittgenstein's death, many still consider it one of the finest works of 20th century philosophy.

Western thinking about the Middle and Far East has been distorted by stereotype and inaccuracy. This argument lies at the center of Palestinian-American literary theorist Edward Said's groundbreaking book, Orientalism. Originally published in 1978, it cemented Said's reputation as the father of postcolonial studies.