Melvyn Bragg and his guests discuss Plato's Symposium, one of the Greek philosopher's most celebrated works. Written in the 4th century BC, it is a dialogue set at a dinner party attended by a number of prominent ancient Athenians, including the philosopher Socrates and the playwright Aristophanes. Each of the guests speaks of Eros, or erotic love. This fictional discussion of the nature of love, how and why it arises and what it means to be in love, has had a significant influence on later thinkers, and is the origin of the modern notion of Platonic love.

With:

Angie Hobbs

Richard Hunter

Frisbee Sheffield

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Medici family, who dominated Florence's political and cultural life for three centuries. The House of Medici came to prominence in Italy in the fifteenth century as a result of the wealth they had built up through banking. With the rise of Cosimo de' Medici, they became Florence's most powerful and influential dynasty, effectively controlling the city's government. Their patronage of the arts turned Florence into a leading centre of the Renaissance and the Medici Bank was one of the most successful institutions of its day. As well as producing four popes, members of the House of Medici married into various European royal families.

With:

Evelyn Welch

Robert Black

Catherine Fletcher

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss complexity and how it can help us understand the world around us. When living beings come together and act in a group, they do so in complicated and unpredictable ways: societies often behave very differently from the individuals within them. Complexity was a phenomenon little understood a generation ago, but research into complex systems now has important applications in many different fields, from biology to political science. Today it is being used to explain how birds flock, to predict traffic flow in cities and to study the spread of diseases.

With:

Ian Stewart

Jeff Johnson

Professor Eve Mitleton-Kelly

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the life and work of Pliny the Younger, famous for his letters. A prominent lawyer in Rome in the first century AD, Pliny later became governor of the province of Bithynia, on the Black Sea coast of modern Turkey. Throughout his career he was a prolific letter-writer, sharing his thoughts with great contemporaries including the historian Tacitus, and asking the advice of the Emperor Trajan. Pliny's letters offer fascinating insights into life in ancient Rome and its empire, from the mundane details of irrigation schemes to his vivid eyewitness account of the eruption of Vesuvius.

With:

Catharine Edwards

Roy Gibson

Alice König

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Hindu ideas about Creation. According to most Western religious traditions, a deity was the original creator of the Universe. Hinduism, on the other hand, has no single creation story. For thousands of years, Hindu thinkers have taken a variety of approaches to the question of where we come from, with some making the case for divine intervention and others asking whether it is even possible for humans to comprehend the nature of creation. The origin of our existence, and the nature of the Universe we live in, is one of the richest strands of Hindu thought.

With:

Jessica Frazier

Chakravarthi Ram-Prasad

Gavin Flood

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the development of the microscope, an instrument which has revolutionised our knowledge of the world and the organisms that inhabit it. In the seventeenth century the pioneering work of two scientists, the Dutchman Antonie van Leeuwenhoek and Robert Hooke in England, revealed the teeming microscopic world that exists at scales beyond the capabilities of the naked eye.

The microscope became an essential component of scientific enquiry by the nineteenth century, but in the 1930s a German physicist, Ernst Ruska, discovered that by using a beam of electrons he could view structures much tinier than was possible using visible light. Today light and electron microscopy are among the most powerful tools at the disposal of modern science, and new techniques are still being developed.

With:

Jim Bennett

Sir Colin Humphreys

Michelle Peckham

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the life of Pocahontas, the Native American woman who to English eyes became a symbol of the New World. During the colonisation of Virginia in the first years of the seventeenth century, Pocahontas famously saved the life of an English prisoner, John Smith. Later captured, she converted to Christianity, married a settler and travelled to England where she was regarded as a curiosity. She died in 1617 at the age of 22 and was buried in Gravesend; her story has fascinated generations on both sides of the Atlantic, and has been reinterpreted and retold by many writers and artists.

With:

Susan Castillo

Tim Lockley

Jacqueline Fear-Segal

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Shakespeare's play The Tempest. Written in around 1610, it is thought to be one of the playwright's final works and contains some of the most poetic and memorable passages in all his output. It was influenced by accounts of distant lands written by contemporary explorers, and by the complex international politics of the early Jacobean age.

The Tempest is set entirely on an unnamed island inhabited by the magician Prospero, his daughter Miranda and the monstrous Caliban, one of the most intriguing characters in Shakespeare's output. Its themes include magic and the nature of theatre itself - and some modern critics have seen it as an early meditation on the ethics of colonialism.

With:

Jonathan Bate

Erin Sullivan

Katherine Duncan-Jones

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss Ordinary Language Philosophy, a school of thought which emerged in Oxford in the years following World War II. With its roots in the work of Ludwig Wittgenstein, Ordinary Language Philosophy is concerned with the meanings of words as used in everyday speech. Its adherents believed that many philosophical problems were created by the misuse of words, and that if such 'ordinary language' were correctly analysed, such problems would disappear. Philosophers associated with the school include some of the most distinguished British thinkers of the twentieth century, such as Gilbert Ryle and JL Austin.

With:

Stephen Mulhall

Ray Monk

Julia Tanney

Producer: Thomas Morris.

Melvyn Bragg and his guests discuss the Berlin Conference of 1884. In the 1880s, as colonial powers attempted to increase their spheres of influence in Africa, tensions began to grow between European nations including Britain, Belgium and France. In 1884 the German Chancellor, Otto von Bismarck, brought together many of Europe's leading statesmen to discuss trade and colonial activities in Africa. Although the original purpose of the summit was to settle the question of territorial rights in West Africa, negotiations eventually dealt with the entire continent. The conference was part of the process known as the Scramble for Africa, and the decisions reached at it had effects which have lasted to the present day. The conference is commonly seen as one of the most significant events of the so-called Scramble for Africa; in the following decades, European nations laid claim to most of the continent.

With:

Richard Drayton

Richard Rathbone

Joanna Lewis

Producer: Thomas Morris.