Historically Thinking

On October 16, 1843, William Rowan Hamilton was taking a walk with his wife Helen. He was on his way to preside over a meeting of the Royal Irish Academy. As Hamilton came to Broome Bridge, over the Royal Canal, the solution to a vexing problem finally emerged in front of him. He was so excited, and perhaps so afraid that he might forget, that he pulled out his penknife and carved the equation he had so suddenly conceived on the stonework of the bridge. That might not seem like such a revolutionary moment. But as my guest Robyn Arianrohd explains, Hamilton’s equation was the result of long centuries of mathematical effort. And its consequences would be immense. Because Hamilton’s thought made possible the concepts known as vectors and tensors. And vectors and tensors underlie much of modern science and technology, because they are used whenever a scientist or an engineer wants to use locations in space–everything from designing a bridge, to predicting the path of a gravitational wave; and there’s quite a lot of territory in between those two applications. That moment by the Broome Bridge ushered in a new era. Robyn Arianrohd is a mathematician, and a historian of science. Her previous books include Thomas Harriot: A Life in Science, which she and I discussed in a conversation that was published on April 30, 2019. Her latest book is Vector: A Surprising Story of Space, Time, and Mathematical Transformation. For show notes, resources, and our archive, go the Historically Thinking Substack ChaptersThomas Harriet and the Birth of Modern AlgebraNavigation, Collisions, and Early Vector ConceptsNewton's Definition of Force and DirectionAugustus De Morgan and the Formalization of AlgebraHamilton's Breakthrough: Quaternions and Four DimensionsThe Non-Commutative RevolutionJames Clerk Maxwell and Electromagnetic TheoryMaxwell's Equations and the Nature of LightThe Vector Wars: Quaternions vs. VectorsTensors: Beyond Vectors to General RelativityThe Playful Seriousness of Mathematical DiscoveryConclusion: The Journey into History of Mathematics

“Oral history is a field of study and a method of gathering, preserving, and interpreting the voices and memories of people, communities, and participants in past events.” That is the definition provided by no less an authority than the Oral History Association. And yet this brief, simple, and seemingly authoritative definition is accompanied by some ambiguity. On the one hand the Oral History Association proclaims that oral history is the oldest type of historical inquiry, stemming back to the origins of humanity itself. But on the other hand, oral history is one of the newest types of historical discipline, owing its birth to the invention of recording technology, and its rapid technological , from the introduction of magnetic tape recorders as consumer devices in 1947, to in 2025 the widespread field use of the superb digital recording studio and processor you typically refer to as your “phone”.With us to explain the basics of the discipline of Oral History is Douglas A. Boyd. He is an oral historian, archivist, folklorist, musician, author and currently Director of the Louie B. Nunn Center for Oral History at the University of Kentucky. He is co-editor of Oral History and Digital Humanities: Voice, Access, Engagement (2014), producer of the documentary Kentucky Bourbon Tales: Distilling the Family Spirit, and author of Crawfish Bottom: Recovering a Lost Kentucky Community. But most recently he is the author of Oral History: A Very Short Introduction, which is the subject of our conversation today.For more show notes, and our full archive, go to the Historically Thinking SubstackChapters00:00:00 Introduction: Defining Oral History00:01:53 The Ambiguity and Multidisciplinary Nature of Oral History00:07:34 The Modern History of Oral History and Recording Technology00:21:07 Early Recording Technology and the Evolution of Interviews00:34:27 Oral History vs. Oral Tradition00:36:51 What Makes an Oral History Interview Different00:41:17 The First Question: Tell Me About Yourself00:47:19 Avoiding Leading Questions00:50:37 The Power of Silence and Active Listening00:54:07 The Art of Being Prepared Without Being a Know-It-All01:03:26 The Digital Archive and Preservation Challenges01:07:47 Enhancing Access and Discovery in the Digital Age01:14:16 Ethical Access and Privacy Concerns01:15:33 Practical Advice for Thanksgiving Interviews01:19:49 Getting Started: Simple Questions and Curiosity01:23:09 The Value of Multiple Sessions and Follow-Up Interviews01:25:56 Closing Remarks

“Two years and a half years ago, when coming down the Nile in a dahabiah, I stopped at . . . Tel el-Amarna. In the course of my exploration, I noticed . . . the foundations of a large building, which had just been laid bare by the natives. . . . A few months afterwards the natives, still going on with their work of disinterment, discovered among the foundations a number of clay tablets covered with characters the like of which had not previously been seen in the land of Egypt.”Those were the words of Archibald Henry Sayce, linguist, valetudinarian, and eventually first Professor of  Assyriology at the University of Oxford. What he had noticed was the uncovering of the Amarna Letters, a set of clay tablets written in cuneiform, about which Sayce–and many others–would be intensively concerned. Finding these letters was like uncovering a file cabinet in the Pharoah of Egypt’s foreign ministry, suddenly providing a set of written sources that illuminated unknown areas of the past.With me to talk about the Amarna letter is Eric H. Cline. He is professor of classics and anthropology at George Washington University, and author most recently of Love, War, and Diplomacy: The Discovery of the Amarna Letters and the Bronze Age World They Revealed. This is his third appearance on the podcast.For this episode's show notes, and other resources, go to the Historically Thinking SubstackChapter OutlineIntroduction & Discovery of the Amarna Letters (00:00)Illicit Excavations & Context (04:45)The Translation Race (14:52)The World of the Letters: Great Kings & Diplomacy (29:00)Local Rulers & Conflicts (43:08)Social Network Analysis (51:57)Modern Relevance & Conclusion (57:41)

For at least two centuries, ideas of international relations and grand strategy have been premised on the notion of “great powers.” These were mighty states uniquely able to exert their influence through overwhelming military force. In the words of friend of the podcast Leopold von Ranke, a great power was one who could “maintain itself against all others, even when they are united”—but my guest, Phillips Payson O’Brien, argues that this definition is ahistorical nonsense.Indeed “great power” he says, has always been a tautology. Nor has it been helpful or accurate to focus who has the biggest armies. And dreaming of decisive battle has blinded us to what truly determines victory: the capacity to mobilize and sustain industrial power, logistics, technology, and global reach.In his new book War and Power: Who Wins Wars and Why, O’Brien dismantles some popular myths of military and diplomatic history and replaces them with a far more dynamic picture—one that redefines how states fight, how they win, and how we should understand power itself in the twenty-first century.For this episode's show notes, and other resources, go to the Historically Thinking SubstackChapters & Timestamps00:28 – Introduction: Challenging the Great Power Myth03:25 – The Persistence of Short War Myths08:22 – The Political Nature of Warfare14:06 – Power Rightly Understood: Economic and Technological Strength20:59 – Society, Structure, and the British-American Power Transition27:36 – Constructing and Regenerating Military Forces46:16 – The Importance of Strong Alliances39:23 – Understanding War: Beyond Battles and Single Weapons45:16 – Human Elements: Leadership, Training, and Morale49:54 – Technological Adaptation: From WWI Aircraft to Modern Drones57:30 – Applied History and the Problem of Transparency57:52 – Outro / Credits

The young King was determined to strike. His throne and power had been taken from him; now he would seize them both back. Now his chosen men entered the castle where he was a virtual prisoner, under the watchful eyes of his mother and her lover. Joining them, he led their rush to the Queen Mother’s apartments. There they seized those who had prevented Edward III from truly ruling as King of England. Those dramatic events–which occurred in Nottingham Castle, of all places–are just one of many that occur in Michael Livingston’s new book, Bloody Crowns: A New History of the Hundred Year’s War. From the origins of the great conflict between France and England, to the last bitter acts, Livingston weaves the story of how not just those two powers but all Europe was riven by a war that last not just for a hundred years, but for two full centuries of war from 1292 to 1492.Michael Livingston is Citadel Distinguished Professor at The Citadel and the author of many books on medieval military history. The former secretary-general for the US Commission on Military History, he lives in Charleston, South Carolina.For more information, see the show notes for this episode on Historically Thinking Substack page.Defining the 200 Years War: 1292 to 1492Cantering Through 200 YearsScotland: The Enemy in the RearDoctrine and the Birth of Standing ArmiesThe Forgotten Naval WarAnarchy, Free Companies, and Peasant RevoltsThe Longbow: Myth vs. RealityThe Papacy and Religious SchismThe Myth of the Decisive BattleGenerational Conflict and Modern ParallelsConclusion

During the Second World War Germany’s submarines sank over three thousand Allied ships, that figure amounting to nearly three-quarters of Allied shipping losses in all theaters of the war. What would become a war within a war began in the very first days after September 1, 1939. This war–particularly the contest which has become known as the Battle of the Atlantic–has been the focus of numerous studies and arguments. But until now, little has been said about the undersea war from the perspective of the German submariners.Roger Moorhouse has now remedied that with his new book Wolfpack: Inside Hitler’s U-boat War. It is not simply a story of the undersea war, but a history of those who fought it; who endured the miserable conditions within a German U-Boat, had only a 25% chance of survival, and when they did survive often were psychologically scarred for the remainder of their lives.Roger Moorhouse is a historian of the Second World War. The author of numerous books, his most recent was The Forgers: The Forgotten Story of the Holocaust’s Most Audacious Rescue Operation, which we discussed in a conversation of November 6, 2023. For more information, including to resources mentioned in the conversation, go to our Substack page, at www.historicallythinking.org

At the outbreak of the American Revolution, the British Empire stretched across nearly every corner of the globe. From India to the Caribbean, from Africa to Gibraltar to the Canadian provinces, Britain’s reach was vast. In 1776, the thirteen colonies that chose to rebel represented only half of the empire’s provinces. The other half—places like Quebec, Nova Scotia, Jamaica, and Bermuda—remained loyal to the Crown. But why? Why did some colonists believe their grievances justified independence, while others–who were often similarly aggrieved–chose not to revolt?To answer this, Trevor Burnard and Andrew Jackson O’Shaughnessy invite us to see the Revolution not just as a national story of the United States, but as part of a larger imperial crisis that spanned the globe. Britain’s challenge was to govern an array of distant, diverse territories during a period of reform and unrest. Turning our attention to colonies that stayed within the empire, we gain a more complex perspective. The Revolution was not only about republicanism, liberty, and democracy; it was also about empire, and the different ways colonial societies and elites responded to imperial governance.For show notes and other material, go to https://www.historicallythinking.org/p/republic-and-empire?r=257pn6; and subscribe to the Historically Thinking Substack at www.historicallythinking.org

In online debates, it’s almost inevitable that sooner or later someone invokes Hitler or the Nazis. That tendency, known as Godwin’s Law, has proven itself on social media thousands of times a day. But the persistence of this comparison points to something deeper than just the cheapening of argument. It reflects how much Hitler and the struggle against Nazism have become the ultimate reference point in our culture’s moral imagination.In this conversation, historian Alec Ryrie explains why we live in what he calls “the Age of Hitler.” For nearly eighty years, he argues, our moral consensus has been defined not by traditional religious frameworks but by the lessons drawn from World War II and the Holocaust. In our stories and our politics, from Star Wars to Harry Potter, the fight against Hitler continues to serve as the archetype of good versus evil. Yet Ryrie warns that this consensus is beginning to erode: both Left and Right are showing signs of moving on. What happens when Hitler no longer defines our common moral language? And what might replace it?For more resources, go to this episode's Substack page: https://www.historicallythinking.org/p/the-age-of-hitler-and-how-we-will?r=257pn6

In this episode of Historically Thinking, host Al Zambone speaks with historian Peter Fritzsche about his book "1942: When World War II Engulfed the Globe." The conversation explores how 1942 marked the transformation of regional conflicts into a truly global war, examining the unprecedented scale and movement of the conflict, the suffering and displacement of millions, and the ideological forces at play in every one of the warring powers. Key topics include the Holocaust, anti-colonial movements, industrial mobilization, and how the memory of World War II has been shaped by the specter of World War III.00:00 — Introduction: 1942 as a Pivotal Year05:16 — Movement and Kinetic Energy in 194207:54 — The Scale of World War II: Numbers Beyond Comprehension08:55 — Pearl Harbor and the Five Decisive Days12:28 — Hitler's Declaration of War on the United States15:09 — American Industrial Mobilization17:42 — Japanese Military Strategy and Pearl Harbor19:29 — Japanese American Internment22:34 — The Global Theater of War and Radio26:31 — The Fall of Singapore and Anti-Colonial Movements31:51 — Cross-Cutting Forces: India's Complex Independence Struggle33:55 — Trotzdem: Hitler's Ideology of Total War35:48 — 1942: The Year of the Holocaust39:52 — Ideological Coherence in World War II Armies43:17 — The Importance of Mail in Maintaining Morale46:11 — Richmond, California: The Second Gold Rush48:08 — The Philippines: Between Two Empires50:32 — Ukraine: Caught Between Empires53:56 — How World War III Obscured World War II

Mount Fuji is at once instantly familiar and seemingly immutable, yet it always remains strange and changeable. Its postcard-perfect peak is known around the world as a wonder of nature and a symbol of Japan. But behind that outline lies a far more complicated history.Over the centuries, Fuji’s eruptions devastated farmland and terrified villagers. Revered as a sacred presence, its divine inhabitants changed with shifts in belief and power. Once locally known, Fuji later became claimed as a national emblem, its slopes inspiring poetry, painting, and pilgrimage—and serving as the stage for political and economic disputes.In Fuji: A Mountain in the Making (Princeton, 2025), Andrew Bernstein traces this layered story from the mountain’s surprisingly recent geological beginnings to its recognition as a World Heritage Site. The result is a portrait of a place both familiar and unsettled: a mountain still in the making, continually remade by the humans who live with it, use it, revere it, and visit it.For show notes and more, go to the Historically Thinking Substack page for this episode.