Aristotle was a philosopher, teacher, collector and all-round polymath. He was also, importantly, a traveller, who allowed new places, especially the rich biodiversity he encountered on the island of Lesbos, to shape his thinking profoundly.

Aristotle’s observations about the natural world were remarkably accurate. Many were proved correct by modern science thousands of years later. He dissected animals, not as his contemporaries did, to understand the will of the gods, but to understand animals for their own sakes. He believed – and encouraged us to consider – that everyone has an innate curiosity about the world, that everyone can try to understand its wonder.

Special thanks to  Sophia Connell, Reader in Philosophy at Birkbeck, University of London.

Produced by BBC Studios Audio in partnership with The Open University.

Presenter: Naomi Alderman Executive editor: Philip Sellars Series producer: Sarah Goodman Script editor: Sara Joyner Researchers: Harry Burton and Miriam O'Byrne Production coordinator: Amelia Paul

Naomi Alderman looks at the mindset and legacy of Ida Pfeiffer, a woman who changed the very idea of travel, who is allowed to do it and why.

Traditionally, travelling had always had a purpose – conquering, discovering, negotiating, pilgrimaging. Women were always accompanied by men – husbands, fathers, brothers, guardians. But in the mid-nineteenth century, a separated mother of two upped sticks and travelled twice around the world, all because she wanted to.

Ida Pfeiffer went on bush expeditions with tiger hunters in India and had dinner with Queen Pomare IV of Tahiti. She spent her fiftieth birthday riding camels through Iran. So many people must have yearned for this kind of adventure, thought about it, but never turned the idea into reality. Pfeiffer made it happen. But what was so different about her thinking?

Special thanks to John van Wyhe, historian of science at the National University of Singapore and author of Wanderlust: The Amazing Ida Pfeiffer, the First Female Tourist (National University of Singapore Press, 2020).

Produced by BBC Studios Audio in partnership with The Open University.

Sir Patrick Manson shook the medical world when he first understood the infection route for vector-borne diseases like malaria. Naomi Alderman dissects the thinking of a scientific pioneer.

In the late 1800s, no one knew how this kind of illness was spread. Manson, a Scottish physician working in China and later in a home laboratory in London, doggedly pursued the answer. Known as the father of tropical medicine, his understanding has undoubtedly saved lives, although he hoped it would also further the Empire. Where might his discovery take us in future?

Special thanks to Kristin Hussey, Lecturer in Environmental History at Newcastle University and author of Imperial Bodies in London (University of Pittsburgh Press, 2021).

Produced by BBC Studios Audio in partnership with The Open University.

Jean Rhys' sequel to Jane Eyre, Wide Sargasso Sea, changed the way we think about stories forever. Naomi Alderman meets a fellow novelist who put a marginalised character at the centre of the action.

Rhys left Dominica to go to school in cold, grey England, but she had always felt out of place. A perfectionist who needed every word in just the right place, she took decades to publish her masterpiece. She was a thinker ahead of her time, who crammed the whole world and its injustices into her writing.

Special thanks to Sophie Oliver, Senior Lecturer in Modernism at the University of Liverpool.

Produced by BBC Studios Audio in partnership with The Open University.

Naomi Alderman explores the thinking of the Buddha, who, as a young prince, ventured outside the palace walls and began his journey towards enlightenment.

Siddhartha Gautama lived in a life of rarefied luxury until an encounter with suffering changed everything for him. He became the Buddha, the awakened one, urged self-transformation and profoundly shaped the world we live in. But did his many insights come from thinking, as such, or something else altogether?

Special thanks to Kate Crosby, Numata Professor of Buddhist studies at the University of Oxford.

Produced by BBC Studios Audio in partnership with The Open University.

Albert Einstein was an international pop star of science who urged the US government to build an atom bomb. Naomi Alderman gets into one of the most famous brains of all time.

Einstein rewrote our understanding of universe. He imagined hitching a ride on a light beam and pursued his famous 'thought experiments' to remarkable ends. He was a man who never swam with the tide. Despite a lifelong commitment to pacifism, in 1939, Einstein signed a letter urging the US government to speed up work on the development of a nuclear bomb. Naomi finds out why.

Special thanks to Janna Levin, Professor of Physics and Astronomy at Barnard College of Columbia University.

Produced by BBC Studios Audio in partnership with The Open University.

Presenter: Naomi Alderman Executive editor: Philip Sellars Series producer: Sarah Goodman Script editor: Sara Joyner Researchers: Harry Burton and Miriam O'Byrne Production coordinator: Amelia Paul

Lise Meitner was a world-class physicist, who saw what others could not. She recognised nuclear fission – the splitting of the atom, the powerful energy released – before anyone else. Naomi Alderman finds out how.

Women weren't even allowed to attend lectures at the University of Berlin, when Meitner moved there in 1907. She began her career in a basement workshop, kept away from male students, and went on to build an unimpeachable reputation for scientific precision and brilliance. Her discovery of fission made the atom bomb possible, but she refused to have anything to do with the Manhattan Project.

Special thanks to Frank Close, Professor Emeritus of Theoretical Physics at the University of Oxford and author of Destroyer of Worlds: The Deep History of the Nuclear Age: 1895-1965 (Allen Lane, 2025).

Thanks also to Alex Wellerstein, historian of science at the Stevens Institute of Technology in Hoboken, New Jersey.

Produced by BBC Studios Audio in partnership with The Open University.

Naomi Alderman dives into the amazing intellect of John von Neumann, physicist, mathematician, economist, computer scientist – a visionary who predicted the rise of artificial intelligence decades ahead of time.

As a child, von Neumann could recite the telephone directory and crack jokes in Ancient Greek. He waltzed into the Manhattan Project and solved a problem that had frustrated other top scientists for months. His work on game theory underpins the modern world, from defence strategies to dating apps. But, for all his serious intellectual contributions, von Neumann was a party animal, who did his best thinking surrounded by people and noise.

Special thanks to Ananyo Bhattacharya, chief science writer at the London Institute for Mathematical Sciences and author of The Man from the Future: The Visionary Life of John von Neumann (Allen Lane, 2021).

Produced by BBC Studios Audio in partnership with The Open University.