Here are the Socratic Dialogues presented as Plato designed them to be - living discussions between friends and protagonists, with the personality of Socrates himself coming alive as he deals with a host of subjects, from justice and inspiration to courage, poetry and the gods. Plato's Socratic Dialogues provide a bedrock for classical Western philosophy. For centuries they have been read, studied and discussed via the flat pages of books, but the ideal medium for them is the spoken word.

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.

These five very different Socratic Dialogues date from Plato's later period, when he was revisiting his early thoughts and conclusions and showing a willingness for revision. In Timaeus (mainly a monologue read by David Timson in the title role), Plato considers cosmology in terms of the nature and structure of the universe, the ever-changing physical world and the unchanging eternal world. And he proposes a demiurge as a benevolent creator God.

Here are three important but very different Dialogues from the Middle Period. Symposium, the most well-known in this collection, is concerned with the theme of love. In the house of Agathon, a group of friends - each very different in personality and background - meet to consider and discuss various kinds of love. Each one, Phaedrus, Pausanias, Eryximachus, Aristophanes (the playwright) and Agathon (a prize-winning tragic poet), presents his particular view in a short discourse.

Here, in this second collection of Socratic Dialogues from Plato's Early Period, read by David Rintoul as Socrates with a full cast, are contrasting six works. Often, as with Gorgias, which opens the recording, Socrates combats the popular subjects of sophistry and rhetoric, in direct conversation with Gorgias (a leading sophist teacher), and with one of his pupils, Callicles.

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.

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 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.

Aristotle’s Nicomachean Ethics and Eudemian Ethics represent, in many ways, the Western classical springboard for the systematic study and implementation of ethics, the optimum behaviour of the individual. (By contrast, Aristotle’s Politics concerns the optimum blueprint for the city-state.) It is in the hands of each individual, he argues in these books on personal ethics, to develop a character which bases a life on virtue, with positive but moderate habits.

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.

The remarkable range of Plato's Dialogues is vividly demonstrated by these three works. It opens with Phaedrus, a highly personal discussion between Socrates (David Rintoul) and the young, love-struck Phaedrus (Gunnar Cauthery). They go for a walk outside the walls of Athens and, under a plane tree by the banks of the Ilissus, talk about love - erotic and 'Platonic' love. Socrates endeavours to steer Phaedrus away from infatuation and show him that real love is based on concern for the beloved.

Poetics and Rhetoric are the two major works by Aristotle which, after more than 2,000 years, remain key behavioural handbooks for anyone interested in story, performance, presentation and indeed psychology. The continuing influence of Poetics, for example, is readily discernible even among the scriptwriters of Hollywood!

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.’

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.

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.