Karl Marx, Friedrich Nietzsche, and Sigmund Freud changed the landscape of the modern world. Together they re-imagined global economics, questioned the very foundations of morality and society, and unravelled the workings of the human mind. They were all born in the 19th century, a pivotal, tumultuous age that witnessed revolutions in industry, technology, and politics. Old certainties were breaking down. Science was undermining religious authority. Their challenge was to figure out what makes us human in a fast-evolving world, and to identify the hidden forces and ideas controlling our lives. It was a search that would drive Marx to poverty, and Nietzsche to psychological breakdown. Host Bettany Hughes discovers how these sceptical ‘masters of suspicion’ created ground-breaking, penetrating ways of seeing the world that still shape how we make sense of our lives today.