Religion is at the heart of man’s societies. ‘For a long time,’ Durkheim writes early on in his book, ‘it has been known that the first systems of representations with which men have pictured to themselves the world and themselves were of religious origin.’ Durkheim decided to examine how and why this phenomenon functioned and evolved - by looking specifically at simple societies and their religions, rather than at religions in more complex or developed societies.

One of the most influential books on economics ever written, Thomas Robert Malthus's An Essay on the Principle of Population remains one of the most controversial too. This 1798 work inspired naturalists Charles Darwin and Alfred Russel Wallace to develop the theory of natural selection. But it has also sparked criticism - Karl Marx famously called Malthus a "lackey of the bourgeoisie." Yet this hasn't stopped leading present-day environmentalists from taking up Malthus's ideas.

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.

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.

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.

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.

On the Genealogy of Morality was written in 1887 when Friedrich Nietzsche was at the height of his powers as a philosopher and master of German prose writing. Here, he criticizes the idea that there is just one conception of moral goodness, dissecting the contemporary practice of morality and looking at it from a historical viewpoint. Rather than following a metaphysical or religious approach, Nietzsche adopts a naturalistic framework, which is grounded in history and natural science, to understand our concepts of good and evil in the Christianized Western world.

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.

“The problem of the twentieth century is the problem of the color line,” writes Du Bois, in one of the most prophetic works in all of American literature. First published in 1903, this collection of 15 essays dared to describe the racism that prevailed at that time in America—and to demand an end to it. Du Bois’ writing draws on his early experiences, from teaching in the hills of Tennessee, to the death of his infant son, to his historic break with the conciliatory position of Booker T. Washington.

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.

Frantz Fanon's Black Skin, White Masks offers a radical analysis of the psychological effects of colonization on the colonized. Born in 1925 on the island of Martinique - at the time a French colony - Fanon witnessed firsthand the abuses of white colonizers and the system's effects on his country. His revulsion was only confirmed later in life when he worked as a psychiatrist in Algeria, another French colony. Fanon's work played a pivotal role in the civil rights movements of the 1960s and was later taken up by scholars of postcolonialist studies.

Issues of human rights and freedoms always inflame passions, and John Rawls's A Theory of Justice will do the same. Published in 1971, it links the idea of social justice to a basic sense of fairness that recognizes human rights and freedoms. Controversially, though, it also accepts differences in the distribution of goods and services - as long as they benefit the worst off in society.

Gondolin, beautiful but undiscoverable, is central to the enmity of two of the greatest powers in the world. Morgoth of the uttermost evil seeks in vain to discover the marvellously hidden city of his Elven enemies, while the gods in Valinor refuse to support Ulmo Lord of Waters' designs to protect it. Into this world comes Tuor, cousin of Túrin, and guided unseen by Ulmo he sets out on the fearful journey to Gondolin to warn them of their coming doom.

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.

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.