Man is born free, and everywhere he is in chains. In The Social Contract, Rousseau explores the concept of freedom and the political structures that may enable people to acquire it. He argues that the sovereign power of a state lies not in any one ruler but in the will of the general population. Rousseau argues that the ideal state would be a direct democracy where executive decision making is carried out by citizens who meet in assembly, as they would in the ancient city-state of Athens.

Published in 1797, the Critique of Pure Reason is considered to be one of the foremost philosophical works ever written. In the Critique of Pure Reason, Immanuel Kant explores the foundation of human knowledge and its limits, as well as man's ability to engage in metaphysics.

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.

Underlain by an acute sense of ethics, this provided the basis for his strongly declared, wide-ranging views on many subjects: prohibition of cock-fighting, liberty of the press, universal suffrage, the removal of religious tests for office and even hunting. All were radical ideas for his time. He also proposed the decriminalisation of homosexuality, though even he did not dare to publish his essay on this subject during his lifetime. But An Introduction to the Principles of Morals and Legislation was his major work.

It can be said of very few books that the world was changed as a result of its publication - but this is certainly the case of Capital: A Critique of Political Economy by Karl Marx (1818-1883). Volume 1 appeared (in German) in 1867, and the two subsequent volumes appeared at later dates after the author's death - completed from extensive notes left by Marx himself.

Penguin presents the audiobook edition of The Coddling of the America Mind by Jonathan Haidt and Greg Lukianoff, read by Jonathan Haidt. What doesn't kill you makes you weaker. Always trust your feelings. Life is a battle between good people and evil people. These three Great Untruths contradict basic psychological principles about well-being as well as ancient wisdom from many cultures. And yet they have become increasingly woven into education, culminating in a stifling culture of 'safetyism' that began on American college campuses.

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.

In The Righteous Mind, social psychologist Jonathan Haidt explores the origins of our divisions and points the way forward to mutual understanding. His starting point is moral intuition - the nearly instantaneous perceptions we all have about other people and the things they do. These intuitions feel like self-evident truths, making us righteously certain that those who see things differently are wrong. Haidt shows us how these intuitions differ across cultures, including the cultures of the political left and right.

The Problems of Philosophy is a 1912 book by Bertrand Russell, in which Russell attempts to create a brief and accessible guide to the problems of philosophy. Focusing on problems he believes will provoke positive and constructive discussion, Russell concentrates on knowledge rather than metaphysics: If it is uncertain that external objects exist, how can we then have knowledge of them but by probability? There is no reason to doubt the existence of external objects simply because of sense data.

A Treatise of Human Nature is the first work ever published by David Hume, a man who revolutionized our understanding of philosophy. Hume was an advocate of the skeptical school of philosophy and a key figure in the Scottish Enlightenment. He looks at the nature of human experience and cognition, showing that philosophy and reason can only be reflections of our nature.

In his devastating new book The Madness of Crowds, Douglas Murray examines the 21st century’s most divisive issues: sexuality, gender, technology and race. He reveals the astonishing new culture wars playing out in our workplaces, universities, schools and homes in the names of social justice, identity politics and ‘intersectionality’. We are living through a postmodern era in which the grand narratives of religion and political ideology have collapsed.

Hayek gives the main arguments for the free-market case and presents his manifesto on the "errors of socialism." Hayek argues that socialism has, from its origins, been mistaken on factual, and even on logical, grounds and that its repeated failures in the many different practical applications of socialist ideas that this century has witnessed were the direct outcome of these errors. He labels as the "fatal conceit" the idea that "man is able to shape the world around him according to his wishes."

An immediate sensation when it was first published in two volumes in 1945, Popper's monumental achievement has attained legendary status on both the Left and Right and is credited with inspiring anticommunist dissidents during the Cold War. Arguing that the spirit of free, critical inquiry that governs scientific investigation should also apply to politics, Popper traces the roots of an opposite, authoritarian tendency to a tradition represented by Plato, Marx, and Hegel. 

First published in 1936, Keynes’ ideas had evolved during the difficulties following World War 1 in Europe, and the US crash and the Depression of the 1920s-'30s and the misery of mass unemployment. He deplored the situation where a few individuals or companies stored massive wealth while vast numbers experienced poverty and insecurity (his alarm bells ring today!) and sought to promote initiatives where governments could intervene with social projects to keep money fluctuating.  

A vast canvas of camps, prisons, transit centres and secret police, of informers and spies and interrogators but also of everyday heroism, The Gulag Archipelago is Aleksandr Solzhenitsyn's grand masterwork. Based on the testimony of some 200 survivors, and on the recollection of Solzhenitsyn's own 11 years in labour camps and exile, it chronicles the story of those at the heart of the Soviet Union who opposed Stalin, and for whom the key to survival lay not in hope but in despair.