Discourse on the Origin and Basis of Inequality Among Men by the philosopher Jean-Jacques Rousseau was originally written for an essay competition run by the Dijon Academy of Arts and Sciences in 1754. The question was, "What is the origin of inequality among men, and is it authorized by the natural law?" Rousseau's text is divided into four main parts: a dedication, preface, an extended inquiry into the nature of the individual, and another inquiry into the evolution of the human species within society.

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.

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.

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.

Aristotle's Metaphysics was the first major study of the subject of metaphysics - in other words, an inquiry into 'first philosophy', or 'wisdom'. It differs from Physics which is concerned with the natural world: things which are subject to the laws of nature, things that move and change, are measurable. In Metaphysics, the study falls on 'being qua being' - being insofar as it is being; the causes and principles of being, the causes and principles of substances.

From his perspective in Renaissance Italy, Machiavelli's aim in this classic work was to resolve conflict with the ruling prince, Lorenzo de Medici. Machiavelli based his insights on the way people really are rather than an ideal of how they should be. This is the world's most famous master plan for seizing and holding power. Astonishing in its candor The Prince even today remains a disturbingly realistic and prophetic work on what it takes to be a prince, a king, or a president.

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.

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.

The Decline of the West - Volume 1 published in 1917, Volume 2 in 1922 - has exercised and challenged opinion ever since. It was a huge undertaking by Oswald Spengler (1880-1936), formerly an unpublished historian and philosopher who set out to radically reconsider history - the rise and fall of world civilisations and their cultures. His primary view was to reject the established Eurocentric paradigm (ancient/classical, Medieval - and, following the Renaissance - modern) and to take a totally new perspective.

The title Politics literally means ‘the things concerning the city’. Here, Aristotle considers the important role that politics plays in the life of the community and its contribution to harmonious and virtuous existence. It is divided into eight books and was a cornerstone in political philosophy for centuries despite certain features - including attitudes towards slaves and women - clearly placing its conclusions and advice within the confines of Athenian society of the fourth century BCE.