In his 1807 work Phenomenology of Spirit, G. W. F. Hegel introduced the world to his philosophical system. His most influential work - and the culmination of the German Idealist movement begun in the late 18th century as a response to the works of Immanuel Kant - the book remains one of the undisputed classics of Western thought.

Published in 1961, the year of Frantz Fanon's death, The Wretched of the Earth is both a powerful analysis of the psychological effects of colonization and a rallying cry for violent uprising and independence. The book rejects colonial assumptions that the people of colonized countries need to be guided by their European colonizers because they are somehow less evolved or civilized. Fanon argues that violence is justified to purge colonialism not just from the countries themselves, but from the very souls of their inhabitants.

A work that had a huge influence on great thinkers including celebrated German philosopher Immanuel Kant, An Enquiry is Hume's examination of how we obtain information and form beliefs. He argues that we mainly gain knowledge through our senses, a theory known as empiricism. But while the impressions from our senses are key to our beliefs about the world, Hume argues that reason and facts play only a limited part.

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.

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.

How do those in power exercise that power over a state's citizens? French thinker Michel Foucault's 1975 work Discipline and Punish looks to answer this question by investigating the prison system. Foucault does not believe that the modern-day system developed out of reformers' humanitarian concerns. He argues that prison both created and then became part of a bigger system of surveillance that extends throughout society.

Advertisements for soap. The image of a film star. The sight of a car as beautiful as a goddess. We accept all these common objects and experiences as normal parts of our lives and as timeless and universal as myth. But they are also carrying hidden messages that none of us even suspect, as Barthes demonstrates with a unique analysis of the signs that generate meanings and assumptions we all take for granted. These things have been "taken out of history" so that their hidden cultural meanings can be accepted without question.

Robert Sapolsky’s Behave, his now classic account of why humans do good and why they do bad, pointed toward an unsettling conclusion: We may not grasp the precise marriage of nature and nurture that creates the physics and chemistry at the base of human behavior, but that doesn’t mean it doesn’t exist. Now, in Determined, Sapolsky takes his argument all the way, mounting a brilliant (and in his inimitable way, delightful) full-frontal assault on the pleasant fantasy that there is some separate self telling our biology what to do.

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.

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.

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.

Having witnessed some negative effects of democratic revolutions in his native France, Tocqueville visited America in 1831 to see what a functioning republic looked like. His main concerns were that democracy could make people too dependent on the state and that minority voices might not be heard - a problem he termed "the Tyranny of the Majority". By examining America thoroughly, Tocqueville hoped to show how a democratic system could avoid these pitfalls.

Do we need the rules of religion in order to be good people? The German philosopher Immanuel Kant tackles this question in his 1793 text Religion Within the Boundaries of Mere Reason. More than 200 years later, it is still a key text in the shaping of Western religious thought, as well as Kant's most direct discussion of religious themes. Kant tries to look at religious practices in relation to the Enlightenment movement and its firmly held beliefs in the power of reason and personal liberty.

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.

Søren Kierkegaard has long been considered the father of the philosophical movement known as Christian existentialism, which focuses on the living human being. In his major 1849 work, The Sickness unto Death, he takes listeners on a journey from the human self, its spirit, despair and sin, through to faith.