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.

We all want to be liked and appreciated by the people around us, but some of us may let this desire dictate our choices and behaviors in a way that can become unhealthy. In How to Stop People-Pleasing, psychology professor Dr. Wind Goodfriend examines what drives many of us to sacrifice our well-being to please others and offers guidance on how you can set healthy boundaries and start prioritizing yourself.

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.

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.

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.

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.

The promise of America is that the country is based on an idea, one where everyone is created equal and equally free to chart their own course. From 13 newly independent states ratifying a national constitution to the heated debates in the halls of Congress today, American politics is about negotiation over what our country is—and where we are going.

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.

Throughout the 24 lectures of Banned Books, Burned Books: Forbidden Literary Works, author and book critic Professor Maureen Corrigan of Georgetown University will take you on a tour of some of the most challenged and controversial works of literature, from the plays of Shakespeare to 21st-century best-sellers—even including the dictionary and classic fairy tales. You will trace the history, in the United States and Great Britain, of the challenges to books, the censoring of books, book bans, and even burnings.

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.

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.

Heidi Sormaz has a PhD in psychology from Yale University with an emphasis on cognitive psychology, and she’s been a meditation and yoga practitioner and teacher for two decades. She is also a reformed over-thinker, so, she knows exactly what you’re going through—or what you’re (over)thinking, so to speak. Over the 12 engaging lessons of Overcome Your Overthinking, Heidi not only provides the science behind cognitive behavioral therapy but she’ll also arm you with a toolbox of exercises and techniques that are most effective at breaking the spell of overthinking.

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 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.

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.