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.

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 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.

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.

The influence of Plato, his Dialogues and his ‘Academy', cast a long shadow. Around 35 Dialogues, almost all featuring Socrates as the principal figure, are generally ascribed to Plato and form one of the most important threads in Western philosophy. These four Dialogues may fall into the ‘Attributed Texts' category, but they are of sufficient interest to warrant study in our time and when set against the principal canon.

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.

Secunda Secundae is the longest part in this immense undertaking by Thomas Aquinas (1225-1274). His purpose was nothing less than to survey the theological teachings of the Catholic Church, while absorbing, controversially for his time, many other strands of learning and philosophy, varying from ancient Greek (particularly Aristotle) to Muslim writers (Averroes and Avicenna) and the Sephardic Jewish philosopher Moses Maimonides.

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.

Summa Theologica consists of three main parts. The second part is divided two, and this recording presents Prima Secundae - Part I of Part II. Taken in its entirety, Summa Theologica forms an essential contribution to the canon of Catholic doctrine and was written in the last decade of his life by Thomas Aquinas (1225-1274), an Italian-born Dominican friar. Although he died before completing it, the body of thought it contains is a continuing influence to the education and guidance of students of theology in the main Christian traditions.