Thought experiments are “what if” scenarios that invite us to look carefully at how we think and view the world. They’ve been used throughout history by philosophers and other thinkers to explore our intuitions and ways of reasoning, to find solutions to problems, and to expand our knowledge of ourselves and the world. In these 24 eye-opening lectures, Professor Breyer takes you deeply into the historical tradition of thought experiments, shining a light on both the purpose and the outcomes of these compelling mental voyages.

The history of the Constitution is therefore a history of ideas that define our country and our national identity—and it’s a fascinating and revealing story. The US Constitution Through History gives you the opportunity to explore the story of this powerful document, as well as the way our interpretation of it has evolved. In 24 riveting lectures, Professor Eric Berger of the University of Nebraska takes you on a journey through America’s constitutional history. He takes you inside the minds of the Framers and unpacks the ideas that led to the break from England.

The issues addressed by macroeconomics are all around you, all the time—from taxes to inflation to mention of the GDP on the nightly news. By learning the principles of macroeconomics, you’ll be able to go beyond simply hearing the terms to better understanding their relationships to each other and how they create the economic environment in which you live. In fact, macroeconomics with its “big-picture glasses” allows you to better ask—and better try to answer—the biggest questions of our time, questions that impact the lives of billions of people.

The Middle Ages was a time of major historical shifts and transformations. This amazing era reverberates with discoveries, innovations, events, and historical processes that are integral to the world we know now. In these 24 enthralling lectures, Professor Salisbury leads you on a sumptuous tour of this incredible historical epoch, making clear that the remarkable historical currents and advances of the Middle Ages unfolded not only in the West, but across the globe, from Europe, Africa, and the Middle East to Asia, the Americas, and beyond.

Railways are one of the most important inventions in modern history. From the 1825 opening of the Stockton and Darlington Railway in England, trains revolutionized both travel and trade and radically changed the way we experience the world. In the 24 richly illustrated lectures of How Railways Transformed the World, you’ll experience the amazing world and impact of railways, from the early 19th century to today’s futuristic trains, including extensive material on the pleasure and appeal of rail travel today.

In The Black Death: New Lessons from Recent Research, celebrated medievalist Dorsey Armstrong shares the fascinating new story of this old pandemic—revealed by dedicated researchers working with 21st-century technologies and a knowledge of language and history that now provide input from all geographic areas of the medieval world. In seven engaging lectures, Professor Armstrong corrects explanations of the pandemic that are now known to be inaccurate and offers a more robust description of plague biology than has ever been known.

England: From the Fall of Rome to the Norman Conquest takes you through the mists of time to the rugged landscape of the British Isles. Over the course of 24 sweeping lectures, Professor Jennifer Paxton of The Catholic University of America surveys the forging of a great nation from a series of warring kingdoms and migrating peoples. From Germanic tribes to Viking invasions to Irish missionaries, she brings to life an underexamined time and place.

Epigenetics is the science of living DNA, charting the chemical pathways that spur DNA into action by turning genes on and off. While the Human Genome Project of the early 2000s was hailed as the key to understanding human heredity and disease, that historic effort was just the beginning. It has taken epigenetics to fill in the picture, explaining how the fixed code of our genome is implemented in countless living processes.

We’ve been celebrating Earth Day for 50 years, but even the most ardent activists of today would have a hard time picturing the intensity and excitement the first Earth Day in 1970 brought. Before then, no one used the phrase “environmental movement”. But that first Earth Day sparked an unprecedented conversation about pollution, wilderness protection, sprawl, and more. Join Adam Rome, professor of Environment and Sustainability at the University of Buffalo, as he uncovers the motivation for, and the lasting impact of, a national day devoted to environmental awareness.

After Romeo and Juliet, Elizabeth Bennet and Fitzwilliam Darcy might just be the world’s most famous fictional couple. The story of how they fall in love—Pride and Prejudice—has left an indelible imprint on popular culture. Readers, novelists, playwrights, filmmakers, and even zombies can’t leave Pride and Prejudice alone. Which raises the question: Why has this novel, of all Jane Austen’s works, remained the general favorite?

In C. S. Lewis: Writer, Scholar, Seeker, Dr. Sørina Higgins will take you on a fascinating expedition through the life and work of this influential author, examining the crucial events and relationships that shaped his personal, literary, and spiritual journeys.

Meet Agatha Christie, the best-selling novelist in human history. Her writing career spanned six decades, during which time she wrote 66 crime novels, 6 non-crime novels (including romances), and over 150 short stories. Not only was she a phenomenally successful novelist, but she is also the most successful female playwright of all time - her play “The Mousetrap” is the longest-running show in history. As you learn about Christie’s experiences and her storied career, you will better understand how the circumstances of her life shaped her work and vice versa.

In London in the Time of Dickens, you’ll get the unique opportunity to experience the British capital through the eyes of a literary master whose work is inextricably tied to the city and its rich history. Throughout 12 lectures taught by Professor Lillian Nayder of Bates College, you’ll tour the city of London in a time of rapid transformation through the life and work of Charles Dickens, uncovering the history of the metropolis, while also witnessing the everyday experiences of Londoners from all walks of life as Dickens represents them.

In this cutting-edge program, 30 Days to a More Powerful Vocabulary, personal development expert and English enthusiast Dan Strutzel will instruct, enlighten, and inspire you with a concentrated 30-day program that will teach you over 500 words. But, more than teaching you these words, the uniquely designed morning and evening review sessions will ensure that these words become a habit-knit part of your life - and with minimal effort on your part.

“Who are you?” Chances are you’d answer this question by describing the highlights of your personality and life experiences. But if you’d been asked this same question yesterday, you might have responded with a slightly different description. Does that mean you are a particular person today but were a different person yesterday? And what about tomorrow? Welcome to the slippery, shape-shifting nature of memory. As Professor Gabrielle Principe reveals, “you” are the conglomeration of the often-unreliable information your brain decides to feed you at any given moment.

Hannibal Barca is famous for marching an eclectic mix of troops across the Alps and into the Roman heartland during the Second Punic War. But how much do we know about the world Hannibal was born into and came of age in? In Hannibal: The Military Genius Who Almost Conquered Rome, get to know one of history’s most impressive generals from the political and military conflicts that defined his adolescence to the battles that made him famous. These 15 lectures will paint a portrait of not only Hannibal, but also his enemies and allies.

In Understanding Cognitive Biases, you will learn how to recognize biases for what they are, counteract them when necessary, and even use them to your advantage in some instances. In 24 fascinating lectures, Dr. Alexander B. Swan uses examples from psychology experiments, history, politics, movies, TV, comics, social media, and more to illustrate dozens of cognitive biases that affect us all.

Education can be enriching and transformative. It can also be downright excruciating—even demoralizing. When it comes to learning, why are some of us lovers and some of us haters? Welcome to the world of educational psychology, which uses science to explore what causes people to engage and learn, and what we can do to make learning opportunities more enjoyable and impactful. Spoiler alert: Teachers can only do so much. Students, too, must take control of their learning. Unfortunately, many of us never, ahem, learned the skills to do just that.

Why are we scared of ghosts, zombies, vampires, demons, and monsters, when we know they are not real? Why do dark attics give us the creeps? How do writers and directors know exactly what anxieties to tap into, so that we break out in goosebumps, cover our eyes, and cringe? Shannon Scott invites you into the spooky, creepy, and sometimes surprising world of the horror genre to examine how popular scary movies and books manipulate our collective and individual fears—not only to frighten us, but also to address taboo subjects, and to reflect and comment on the state of our society.

From spirituality to politics and science, the occult has had an astonishing influence on the human experience across the centuries. It may surprise you to learn that everyday activities like attending church services or reading your daily horoscope all fit the broad definition of the occult. As you will see in the 24 illuminating episodes of Secrets of the Occult, the mystic and obscure are threaded through our ordinary lives in more ways than you may realize.

The Spanish Civil War was a local conflict on the margins of Europe—a short yet bloody series of battles in a lull between the great World Wars—but the conflict was a microcosm of war in the 20th century. Not only did the Spanish Civil War foreshadow the global conflagration to come, but it also had its roots in the modern era’s central divides: urban versus rural, religion versus secularization, rich versus poor, progress versus tradition, democracy versus fascism and communism.

The glorious repertoire for solo piano includes many of classical music’s most beloved masterpieces. In these 24 musically rich lectures, you’ll dig deeply into this magnificent tradition, in an in-depth exploration of the art of listening. With Professor Kautsky’s inspired guidance and expert playing, you’ll highlight key works of each composer, and unpack their structure, the musical materials that drive them, and the specific features that affect listeners so strongly, giving you a clear grounding in how to approach and hear this great music.

Sleep neurologist Jennifer Molano explores many different aspects of sleep, helping you better understand common sleep issues and providing practical tips to improve sleep in your life. Over the course of six lectures, she will reveal what drives our sleep-wake cycle, what “healthy sleep” is, how our sleep cycles change over time, why sleep is important in regulating systems in our brains and bodies, and what symptoms may occur with sleep disturbances.

Though it ended five centuries ago, the medieval era continues to permeate our world in far-reaching ways. Whether we pay attention to them or not, the influences and imprints of the Middle Ages are all around us, sometimes evident and sometimes less so. In these 36 revealing lectures, you’ll learn how to recognize the medieval impacts on the modern world, and to grasp their significance and implications. The Medieval Legacy offers you a deep look at a stunning millennium of change and innovation which continues to inform our contemporary world.

Whatever the form, whatever the treat - sugar drives us wild like nothing else. It’s lingered on our tongues for millennia and found its way into almost every household in the world. Alas, the history of sugar is far from sweet. Long before it was linked to America’s obesity epidemic, sugar was fueling the dark forces of exploitation, colonization, conquest, and slavery. More than just candy and cake, sugar has drastically altered the diets, cultures, and economies of the modern world. How can we love sugar while having a healthy relationship with its bittersweet history?