Plagued with doubt and uncertainty in sensory knowledge, Descartes is struck with the idea that everything he knows is false. He considers the possibility that he has been deceived by an 'evil demon' and is left with nothing to lean on, until he arrives at the phrase 'cogito ergo sum' ('I think, therefore I am'). Among the most quoted philosophical works in history, Meditations on First Philosophy and Discourse on the Method together display the full workings of Descartes' skeptical method and the formation of his famous phrase.

John Locke (1632-1704) was a product of his troubled times: he lived through the English Civil War, the Interregnum, the Restoration, Monmouth’s Rebellion, the Bloody Assizes and the Glorious Revolution. His empirical thinking was very much directed at finding rational solutions to the root causes of those troubles.

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.

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.

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.

Published in 1748, An Enquiry Concerning Human Understanding is Scottish empiricist philosopher David Hume's distillation of his mature philosophy. Addressing themes including the limits of human understanding, the compatibility of free will with determinism, weaknesses in the foundations of religion, and the appeal of skepticism, An Enquiry Concerning Human Understanding is Hume's attempt to revise and clarify the ideas of his earlier A Treatise of Human Nature.

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.

Inside this brilliant three-in-one book collection, you’ll uncover a wealth of philosophical insights about truth, faith, and the universe around us. Drawing on the arguments and musings of the famed philosopher, David Hume, this book reveals his ideas on the questions that define our very existence. Brought to life in this collection for a modern audience David Hume’s work has stood the test of time to resonate with people across the ages.

Schopenhauer was just 30 when his magnum opus, Die Welt als Wille und Vorstellung, a work of considerable learning and innovation of thought, first appeared in 1818.

Much to his chagrin and puzzlement (so convinced was he of its merits), it didn't have an immediate effect on European philosophy, views and culture. It was only decades later that it was recognised as one of the major intellectual landmarks of the 19th century.

From the moment of its publication in 1748, The Spirit of the Laws proved to be a controversial work provoking widespread interest. Within three years it had been translated into various European languages - and was swiftly added to the List of Prohibited Books by the Roman Catholic Church. It is a remarkable book, a potpourri of observations and comments ranging far and wide over the social activities of mankind and it exerted a great influence on political leaders in the following decades.

First published in 1710, George Berkeley's A Treatise Concerning the Principles of Human Knowledge is a seminal contribution to Empiricist philosophy. Making the bold assertion that the physical world consists only of ideas and thus does not exist outside the mind, this work establishes Berkeley as the founder of the immaterialist school of thought. A major influence on such later philosophers as David Hume and Immanuel Kant, Berkeley's ideas have played a role in such diverse fields as mathematics and metaphysics and continue to spark debate 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.

Critique of Judgement was published in 1790 and is divided into two parts, the Critique of Aesthetic Judgement and the Critique of Teleological Judgement. Our ‘judgements of taste’, as Kant describes our aesthetic judgements, have both a personal and a universal function: personal, because we have a subjective aesthetic response to the ‘agreeable’, the ‘beautiful’, the ‘sublime’ and the ‘good’; but also there is a ‘universal’ aspect because our aesthetic response has a ’disinterested’ element. This brings under Kant’s spotlight, for example, the concept of beauty and the perception of beauty.

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?

In Three Dialogues (set in a ‘Platonic’ garden), Hylas begins by challenging Philonous that he denied the existence of material substance. ‘What!’ says Hylas. ‘Can anything be more fantastical, more repugnant to Common Sense, or a more manifest piece of Scepticism, than to believe there is no such thing as matter?’ And Berkeley, in the guise of Philonous, replies, ‘Softly, good Hylas. What if it should prove that you, who hold there is, are, by virtue of that opinion, a greater sceptic, and maintain more paradoxes and repugnances to common sense, than I who believe no such thing.’

A dialogue between Socrates and Meno probes the subject of ethics. Can goodness be taught? If it can, then we should be able to find teachers capable of instructing others about what is good and bad, right and wrong, or just and unjust.

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.

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?

Two contrasting reflections by Aristotle which cover very particular ground. In 'On the Soul', Aristotle presents his view of the 'life essence' which, he argues, is possessed by living things whether plants, animals or humans. Not a 'soul' in the generally accepted Western use of the term, this 'soul', he says, is a life force that is indivisible from the organism that possesses it.

"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.

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.

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....

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.

In The Dream of Enlightenment, Anthony Gottlieb expertly navigates a second great explosion of thought, taking us to northern Europe in the wake of its wars of religion and the rise of Galilean science. In a relatively short period - from the early 1640s to the eve of the French Revolution - Descartes, Hobbes, Spinoza, Locke, Leibniz, and Hume all made their mark. The Dream of Enlightenment tells their story and that of the birth of modern philosophy.

Christopher Hitchens continues to make the case for a splendidly godless universe in this first-ever gathering of the influential voices past and present that have shaped his side of the current (and raging) God/no-god debate. With Hitchens as your erudite and witty guide, you'll be led through a wealth of philosophy, literature, and scientific inquiry, including generous portions of the words of Lucretius, Benedict de Spinoza, Charles Darwin, Karl Marx, Mark Twain, and more.

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.'"

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.

Where did the ideas come from that became the cornerstone of American democracy? Not only the erudite Thomas Jefferson, the wily and elusive Ben Franklin, and the underappreciated Thomas Paine, but also Ethan Allen, the hero of the Green Mountain Boys, and Thomas Young, the forgotten Founder who kicked off the Boston Tea Party. These radicals who founded America set their sights on a revolution of the mind. Derided as "infidels" and "atheists" in their own time, they wanted to liberate us not just from one king but from the tyranny of supernatural religion.

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.

John Locke (1632-1704) was a product of his troubled times: he lived through the English Civil War, the Interregnum, the Restoration, Monmouth’s Rebellion, the Bloody Assizes and the Glorious Revolution. His empirical thinking was very much directed at finding rational solutions to the root causes of those troubles.

Credited as the Father of Liberalism and revered for his ground-breaking theories, John Locke left behind a legacy which has radically shaped political and philosophical thought for over 300 years. His writings continue to inspire and educate people to this day, from founding our central ideas of consciousness and knowledge to creating a framework for society which greatly influenced America’s founding fathers.

Inside this brilliant three-in-one book collection, you’ll uncover a wealth of philosophical insights about truth, faith, and the universe around us. Drawing on the arguments and musings of the famed philosopher, David Hume, this book reveals his ideas on the questions that define our very existence. Brought to life in this collection for a modern audience David Hume’s work has stood the test of time to resonate with people across the ages.

Critique of Judgement was published in 1790 and is divided into two parts, the Critique of Aesthetic Judgement and the Critique of Teleological Judgement. Our ‘judgements of taste’, as Kant describes our aesthetic judgements, have both a personal and a universal function: personal, because we have a subjective aesthetic response to the ‘agreeable’, the ‘beautiful’, the ‘sublime’ and the ‘good’; but also there is a ‘universal’ aspect because our aesthetic response has a ’disinterested’ element. This brings under Kant’s spotlight, for example, the concept of beauty and the perception of beauty.

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.

Francis Bacon (1561-1626), 1st Viscount St Albans, Attorney General and then Lord Chancellor of England, was an immensely learned, clever and ambitious man, with considerable political influence. However, he was also a philosopher with a wide interest in science, medicine and the classification of knowledge. Throughout his life he wrote a series of essays - following the manner set particularly by Montaigne, though extending back to Aristotle and others - the first 10 of which appeared in 1597.

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.

From the moment of its publication in 1748, The Spirit of the Laws proved to be a controversial work provoking widespread interest. Within three years it had been translated into various European languages - and was swiftly added to the List of Prohibited Books by the Roman Catholic Church. It is a remarkable book, a potpourri of observations and comments ranging far and wide over the social activities of mankind and it exerted a great influence on political leaders in the following decades.

In An Essay Concerning Human Understanding, first published in 1690, John Locke (1632-1704) provides a complete account of how we acquire everyday, mathematical, natural scientific, religious and ethical knowledge. Rejecting the theory that some knowledge is innate in us, Locke argues that it derives from sense perceptions and experience, as analysed and developed by reason. While defending these central claims with vigorous common sense, Locke offers many incidental - and highly influential - reflections on space and time, meaning, free will and personal identity.

Plotinus (204/5 -270 CE), born in Lycopolis, Egypt, when it was part of the Roman Empire, was a major figure in the philosophical school later called Neoplatonism. Neoplatonists viewed reality as deriving from a single force or figure expressed as 'the One'. Two further concepts from Plotinus, 'the Intellect' and 'the Soul', are also principal features of his philosophy. These proposals led to the work of Plotinus forming a bridge between Plato and the monotheistic religions of Christianity, Judaism, and Islam as well as Gnosticism.