What is the nature of truth? We live in an age of fake news and social media, propaganda and conspiracy theories. From politics to pandemic, science to history, our public debates are increasingly divided between alternative versions of the world around us. In such febrile times, how can we go about distinguishing true from false, fact from fiction? Diarmaid Ferriter is a Professor of Modern Irish History at University College Dublin, and a regular columnist with The Irish Times. His work on 20th century Ireland has revised many myths about our recent past, in books about Eamon de Valera, the revolutionary decade, sex and religion, and most recently a history of our offshore islands. At the National Gallery of Ireland, Diarmaid spoke with Dr David Kenny, Assistant Professor of Law at Trinity College Dublin, where they discussed history, law, and different ways of discovering the truth.