Being and Time was published in 1927 during the Weimar period in Germany, a time of political, social and economic turmoil. Heidegger himself did not escape the pressures and his nationalism, and undeniable anti-Semitism in the following decades cast a shadow over the man, but not the work. Being and Time is not coloured by expressions of his later views (unlike other writings) and remains an outstanding document.  

As philosophy professor Taylor Carman explains in his helpful introduction, Edmund Husserl (1859-1938) was the founder of modern phenomenology, one of the most important and influential movements of the 20th century. Ideas, published in 1913 – its full title is Ideas for a Pure Phenomenology and Phenomenological Philosophy – was the key work. It is arguably ‘the most fundamental and comprehensive statement of the fundamental principles of Husserl’s mature philosophy’. 

Philosophical Investigations was published in 1953, two years after the death of its author. In the preface written in Cambridge in 1945 where he was professor of philosophy he states: ‘Four years ago I had occasion to re-read my first book (the Tractatus Logico-Philosophicus) and to explain its ideas to someone. It suddenly seemed to me that I should publish those old thoughts and the new ones together: that the latter could be seen in the right light only by contrast with and against the background of my old way of thinking.’

A work of striking originality, The Human Condition is in many respects more relevant now than when it first appeared in 1958. In her study of the state of modern humanity, Hannah Arendt considers humankind from the perspective of the actions of which it is capable. The problems Arendt identified then - diminishing human agency and political freedom, the paradox that as human powers increase through technological and humanistic inquiry, we are less equipped to control the consequences of our actions - continue to confront us today.  

This Leibniz collection contains some of the philosopher’s most important works and ideas, spans three decades and illuminates the fascinating intellectual journey undertaken by him in his quest for truth. A prodigious polymath, Leibniz was a mathematician, philosopher, physicist and statesman and engaged with a sweeping range of ideas and disciplines, striving throughout his life to be at the cutting edge of scientific thinking. These Principal Essays are arranged in chronological order. 

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. 

Chrétien de Troyes' Perceval is the single most important Arthurian romance. It contains the very first mention of the mysterious grail, later to become the Holy Grail and the focal point of the spiritual quest of the knights of Arthur's court. Chrétien left the poem unfinished, but the extraordinary and intriguing theme of the Grail was too good to leave, and other poets continued and eventually completed it.

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.

Van Norden’s Introduction to Classical Chinese Philosophy is evidently of increasing importance in balancing our 21st century view of philosophy in general. It is to Van Norden’s regret, that when ‘philosophy’ is discussed or taught, it is almost always in the context of ‘Western Philosophy’ rather than a global perspective. Yet the contribution of China to global thought and understanding is crucial, especially in our contemporary context. 

The French thinker and political theorist Georges Sorel (1847-1922), fired up by his interest in Marxism and his anger at the injustice of the Dreyfus case, faced this challenge and in the seven chapters of Reflections on Violence he explored the question. It proved sufficiently stimulating over succeeding decades to be espoused by both Marxists and Fascists alike: class struggle, revolution and above all radical change were central to Sorel’s thought.  

This collection of 11 wide-ranging lectures which appeared originally in 1933, was based on lectures previously given when Jung was in the process of absorbing a considerable period of study of Eastern religions, Gnosticism and other religious sources. It was a time, according to the translator Cary F. Baynes, ‘when the Western world stands on the verge of a spiritual rebirth...after a long period of outward expansion, we are beginning to look inside ourselves once more.’ 

Nietzsche never recovered from his mental breakdown in 1889 and therefore was unable to further any plans he had for the ‘magnum opus’ he had once intended, bringing together in a coherent whole his mature philosophy. It was left to his close friend Heinrich Köselitz and his sister Elizabeth Förster-Nietzsche to go through the remaining notebooks and unpublished writings, choosing sections of particular interest to produce The Will to Power, giving it the subtitle An Attempted Transvaluation of All Values. 

The basic principles that Bergson articulates, especially his way of thinking about reality as a dynamic process and his view of human beings as creative and evolving, should be helpful to anyone who seeks to go beyond simply dealing with the practical demands of daily life and consider the nature of things. Of special importance is Bergson’s claim that it is both possible and necessary to know from the inside rather than confining our attention to external perspectives and points of view. Intuition is able to get beyond what is relative and place us inside reality.

Simone de Beauvoir’s essential masterwork is a powerful analysis of the Western notion of "woman", and a revolutionary exploration of inequality and otherness. This unabridged edition of the text reinstates significant portions of the original French text that were cut in the first English translation, and is now available on audio for the very first time. Vital and groundbreaking, Beauvoir’s pioneering and impressive text remains as pertinent today as when it was first published, and will continue to provoke and inspire generations of men and women to come.

Though Karl Marx is best known for Capital and The Communist Manifesto, his revolutionary thoughts and ideas had developed over decades spent in study, discussion and association with a variety of organisations throughout Europe and the US, intent on challenging the establishment order. These six very different texts show how Marx’s ideas evolved and how increasingly fierce his views became.