From the perspective of an unbeliever, Fear and Trembling explores the paradox of faith, the nature of Christianity, and the complexity of human emotion. Kierkegaard examines the biblical story of Abraham, who was instructed to sacrifice his son Isaac, and forces us to consider Abraham's state of mind. What drove Abraham, and what made him carry out such an absurd and extreme request from God? Kierkegaard argues that Abraham's agreement to sacrifice Isaac, and his suspension of reason, elevated him to the highest level of faith.

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.

Nietzsche was one of the most revolutionary thinkers in Western philosophy and Thus Spoke Zarathustra remains his most influential work. It describes how the ancient Persian prophet Zarathustra descends from his solitude in the mountains to tell the world that God is dead and that the Superman, the human embodiment of divinity, is his successor. With blazing intensity, Nietzsche argues that the meaning of existence is not to be found in religious pieties or meek submission, but in an all-powerful life force: passionate, chaotic and free.

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.

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.’