Immanuel Kant’s Critique of Pure Reason can lay claim to being the most important single work of modern philosophy, a work whose methodology, if not necessarily always its conclusions, has had a profound influence on almost all subsequent philosophical discourse. In this work Kant addresses, in a groundbreaking elucidation of the nature of reason, the age-old question of philosophy: “How do we know what we know?” and the limits of what it is that we can know with certainty.

Rene Descartes is often described as the first modern philosopher, but much of the content of his Meditations on First Philosophy can be found in the medieval period that had already existed for more than a thousand years. Does God exist? If so, what is his nature? Is the human soul immortal? How does it differ from the body? What role do sense experience and pure reason play in knowing?

By calling everything into doubt, Descartes laid the foundations of modern philosophy. With the celebrated words "I think therefore I am," his compelling argument swept aside ancient and medieval traditions. He deduced that human beings consist of minds and bodies; that these are totally distinct "substances"; that God exists and that He ensures we can trust the evidence of our senses.

A landmark in the history of thought, Rene Descartes' Meditations helped bring critical thinking and skepticism to the Western world. Modern philosophers are still captivated by Descartes' radical and controversial departure from his previous beliefs, which has both inspired reverence and provoked anger.

The leviathan is the vast unity of the State. But how are unity, peace, and security to be attained? Hobbes’ answer is sovereignty, but the resurgence of interest today in Leviathan is due less to its answers than its methods: Hobbes sees politics as a science capable of the same axiomatic approach as geometry.

Stephen Hawking not only unraveled some of the universe's greatest mysteries but also believed science plays a critical role in fixing problems here on Earth. Now, as we face immense challenges on our planet - including climate change, the threat of nuclear war, and the development of artificial intelligence - he turns his attention to the most urgent issues facing us. Will humanity survive? Should we colonize space? Does God exist? These are just a few of the questions Hawking addresses in this wide-ranging, passionately argued final book from one of the greatest minds in history.

Aristotle was a Greek philosopher and polymath during the Classical period in Ancient Greece. His writings cover many subjects including physics, biology, zoology, metaphysics, logic, ethics, aesthetics, poetry, theatre, music, rhetoric, psychology, linguistics, economics, politics and government.

One of the most significant books ever written by a head of state, the Meditations are a collection of philosophical thoughts by the Emperor Marcus Aurelius (121 - 180 ce). Covering issues such as duty, forgiveness, brotherhood, strength in adversity and the best way to approach life and death, the Meditations have inspired thinkers, poets and politicians since their first publication more than 500 years ago. Today, the book stands as one of the great guides and companions - a cornerstone of Western thought.

Continuing where Thus Spoke Zarathustra left off, Nietzsche's controversial work Beyond Good and Evil is one of the most influential philosophical texts of the 19th century and one of the most controversial works of ideology ever written. Attacking the notion of morality as nothing more than institutionalised weakness, Nietzsche criticises past philosophers for their unquestioning acceptance of moral precepts. Nietzsche tried to formulate what he called "the philosophy of the future".

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.

The Republic poses questions that endure: What is justice? What form of community fosters the best possible life for human beings? What is the nature and destiny of the soul? What form of education provides the best leaders for a good republic? What are the various forms of poetry and the other arts, and which ones should be fostered and which ones should be discouraged? How does knowing differ from believing?

E. H. Gombrich's world history, an international best seller now available in English for the first time, is a text dominated not by dates and facts but by the sweep of experience across the centuries, a guide to humanity's achievements, and an acute witness to its frailties.

Hegel is regarded as one of the most influential figures on modern political and intellectual development. After painting Hegel's life and times in broad strokes, Peter Singer goes on to tackle some of the more challenging aspects of Hegel's philosophy. Offering a broad discussion of Hegel's ideas and an account of his major works, Singer explains what have often been considered abstruse and obscure ideas in a clear and inviting manner.

Seeing self-possession as the key to an existence lived 'in accordance with nature', the Stoic philosophy called for the restraint of animal instincts and the importance of upright ethical ideals and virtuous living. Seneca's writings are a profound, powerfully moving and inspiring declaration of the dignity of the individual mind.

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.

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.

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....

The Problems of Philosophy discusses Bertrand Russell's views on philosophy and the problems that arise in the field. Russell's views focus on knowledge rather than the metaphysical realm of philosophy. The Problems with Philosophy revolves around the central question that Russell asks in his opening line of Chapter 1 - Is there any knowledge in the world which is so certain that no reasonable man could doubt it?

Considered by many to be Hannah Arendt's greatest work, published as she neared the end of her life, The Life of the Mind investigates thought itself, as it exists in contemplative life. In a shift from her previous writings, most of which focus on the world outside the mind, this work was planned as three volumes that would explore the activities of the mind considered by Arendt to be fundamental. What emerged is a rich, challenging analysis of human mental activity, considered in terms of thinking, willing, and judging.

This simplistic and ingenious allegory from one of the fathers of Western philosophy casts light on society’s naiveté and ignorance.

He was the father of the occult, the founder of astrology, the discoverer of alchemy. He was Hermes Trismegistus, and as the scribe of the gods of ancient Egypt, he possessed all divine knowledge... which he passed on to humanity, though only those who have been tutored in its wonders can fully understand it.In this extraordinary 1912 book, three secret initiates to his teachings - who remain anonymous to this day - share their insight with all who seek to understand the mysterious underpinnings of the universe and our relationship with it.

Socrates is in prison, sentenced to die when the sun sets. In this final conversation, he asks what will become of him once he drinks the poison prescribed for his execution. Socrates and his friends examine several arguments designed to prove that the soul is immortal. This quest leads him to the broader topic of the nature of mind and its connection not only to human existence but also to the cosmos itself. What could be a better way to pass the time between now and the sunset?

The Summa Theologica, by Thomas Aquinas, is a fundamental text in Catholic doctrine, a compendium of theology that has been studied and debated since its first publication in the 13th century. Furthermore, it has been widely regarded as one of the classics of Western philosophy, not least because, perhaps for the first time in such a systematic manner, it set out to consider the views of non-Christian figures such as Aristotle, Boethius, Muslim writers including Averroes (Ibn Rushd) and Avicenna (Ibn Sina) and the Sephardic Jewish scholar Maimonides.

Written in 1917, The Law and the Word is a hard-to-find work by Judge Thomas Troward, a pioneer in mental science. Troward's writings and lectures greatly influenced Ernest Holmes, the founder of Religious Science and writer of The Science of Mind.

This book was one of the first to combine thought energy, scientific reasoning and testing, and creative power, and to see the interconnection of the three.

"The central miracle asserted by Christians is the Incarnation. They say that God became Man. Every other miracle prepares the way for this, or results from this." This is the key statement of Miracles, in which C. S. Lewis shows that a Christian must not only accept but rejoice in miracles as a testimony of the unique personal involvement of God in his creation.

Despite the recent ferocious public debate about belief, the concept most central to the discussion "God" frequently remains vaguely and obscurely described. Are those engaged in these arguments even talking about the same thing? In a wide-ranging response to this confusion, esteemed scholar David Bentley Hart pursues a clarification of how the word "God” functions in the world’s great theistic faiths.

One of the most influential philosophers and theologians in the history of Western thought, St Thomas Aquinas established the foundations for much of modern philosophy of religion, and is famous for his arguments for the existence of God. In this cogent and multifaceted introduction to the great saint's work, Edward Feser argues that you cannot fully understand Aquinas' philosophy without his theology, and vice-versa. He covers Aquinas' thoughts on the soul, natural law, metaphysics, and more.

Modern Man in Search of a Soul is the classic introduction to the thought of Carl Jung. Along with Freud and Adler, Jung was one of the chief founders of modern psychiatry. In this book, Jung examines some of the most contested and crucial areas in the field of analytical psychology: dream analysis, the primitive unconscious, and the relationship between psychology and religion.

Already a classic, this landmark study of early Western thought now appears in a new edition with expanded coverage of the Middle Ages. Author Anthony Gottlieb looks afresh at the writings of the great thinkers, questions much of conventional wisdom, and explains his findings with unbridled brilliance and clarity. From the pre-Socratic philosophers through the celebrated days of Socrates, Plato, and Aristotle, up to Renaissance visionaries like Erasmus and Bacon, philosophy emerges here as a phenomenon unconfined by any one discipline.

The Varieties of Religious Experience is considered to be the classic work in the field. To quote Wikipedia, "James was most interested in understanding personal religious experience. The importance of James to the psychology of religion - and to psychology more generally - is difficult to overstate. He discussed many essential issues that remain of vital concern today. What makes James writing so special is that he could take a very complex subject and, without watering it down, make it understandable to 'the rest of us.'"