John Locke and his works - particularly An Essay Concerning Human Understanding - are regularly and rightly presented as foundations for the Age of Enlightenment. His primary epistemological message - that the mind at birth is a blank sheet waiting to be filled by the experiences of the senses - complemented his primary political message: that human beings are free and equal and have the right to envision, create and direct the governments that rule them and the societies within which they live.

Beyond the rehashed clichés, this book inspires us to rediscover Diogenes' philosophical legacy—whether it be the challenge to the established order, the detachment from materialism, the choice of a return to nature, or the formulation of a cosmopolitan ideal strongly rooted in the belief that virtue is better revealed in action than in theory.

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’.

In this classic work, Leo Strauss examines the problem of natural right and argues that there is a firm foundation in reality for the distinction between right and wrong in ethics and politics. On the centenary of Strauss's birth, and the fiftieth anniversary of the Walgreen Lectures which spawned the work, Natural Right and History remains as controversial and essential as ever.

Johann Gottlieb Fichte (1762-1814) was the forerunner of the post-Kantian idealists and remains one of the most important figures in German philosophy. Throughout his career, Fichte published, in addition to his systematic or "scientific" treatises, the best known of which is the "Foundation of the Entire Wissenchaftslehre (1794-5), a series of works directed at the general public.

This audiobook contains all 3 volumes of Capital, a compendium that Marx's collaborator Friedrich Engels described as 'the Bible of the working class'. One of the most notorious and influential works of modern times, Capital is an incisive critique of private property and the social relations it generates.

Against Nature was one of the most shocking French novels of the 19th century. When it was published in 1884, it thrilled the aesthetes, the poets, and the intellectuals of Europe on both sides of the Channel (notably Oscar Wilde) because for all its lofty tone, it had, as its core, an unbridled decadence, and it was this same character that challenged, even horrified, established bourgeois society.

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.

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.

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.

There is a cause, or a reason, behind everything that happens. This is the fundamental view behind the classical proposition the Principle of Sufficient Reason, which, in 1813, Schopenhauer chose as his subject for further examination in his doctoral dissertation On the Fourfold Root of the Principle of Sufficient Reason....

Philosophy of Mind is the third and final part of the Encyclopaedia of the Philosophical Sciences, the collection in which Hegel (1730-1831) offered an overview of his life’s work. Though originally written in 1817, he revised it in 1830, thus providing a finished form the year before his death. Hegel used the three parts of the Encyclopaedia - Science of Logic, Philosophy of Nature and Philosophy of Mind - as a basis for lectures at the Universities of Heidelberg which he joined in 1816, and in Berlin in 1820.

Soren Kierkegaard was a Danish philosopher, theologian, and religious author interested in human psychology. He is regarded as a leading pioneer of existentialism and one of the greatest philosophers of the 19th Century.

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.

William James was one of the most influential figures in 19th-century American philosophy and psychology. His Pragmatism is a set of lectures that he gave in 1906-07 in answer to the enduring debate between empiricism and rationalism. Shifting between them, he proposed pragmatism as a method, the idea being that the value of any truth is dependent upon its utility–upon its practical and experiential consequences.