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.

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.

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.

First published in 1621, and hardly ever out of print since, it is a huge, varied, idiosyncratic, entertaining and learned survey of the experience of melancholy, seen from just about every possible angle that could be imagined. The Anatomy of Melancholy, presented here with all the original quotations in English, is, at last, available on audiobook in its entirety.

Aristotle considers ‘the principles and causes of change, or movement’ behind both animate and inanimate things. It is philosophy, not science, but over centuries affected the views of those involved in the ‘natural sciences’. The text emerged from the Lyceum, the school founded by Aristotle, and is accepted to be a compilation of texts, some of which - but perhaps not all - is by Aristotle. Regardless of authorship, its importance is unquestioned.

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.

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 Organon comprises six key essays on logic, initially collected by Theophrastus, his successor as head of the Peripatetic school, and given its final form by Andronicus some three centuries later. The six essays are: Categories, On Interpretation, Prior Analytics, Posterior Analytics, Topics and On Sophistical Refutations. One of the principal topics of Aristotle’s focus is syllogism, in which two premises (one major, one minor) lead to a conclusion. This features in Prior Analytics and On Interpretation.

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.

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.’