Language defines us as a species, placing humans head and shoulders above even the most proficient animal communicators. But it also beguiles us with its endless mysteries, allowing us to ponder why different languages emerged, why there isn't simply a single language, how languages change over time and whether that's good or bad, and how languages die out and become extinct.

Grasp the important ideas that have served as the backbone of philosophy across the ages with this extraordinary 60-lecture series. This is your opportunity to explore the enormous range of philosophical perspectives and ponder the most important and enduring of human questions-without spending your life poring over dense philosophical texts.

No skill is more important in today's world than being able to think about, understand, and act on information in an effective and responsible way. What's more, at no point in human history have we had access to so much information, with such relative ease, as we do in the 21st century. But because misinformation out there has increased as well, critical thinking is more important than ever. These 24 rewarding lectures equip you with the knowledge and techniques you need to become a savvier, sharper critical thinker in your professional and personal life.

Take a riveting tour of the Italian peninsula, from the glittering canals of Venice to the lavish papal apartments and ancient ruins of Rome. In these 24 lectures, Professor Bartlett traces the development of the Italian city-states of the Middle Ages and the Renaissance, showing how the modern nation of Italy was forged out of the rivalries, allegiances, and traditions of a vibrant and diverse people.

Cosmos is one of the best-selling science books of all time. In clear-eyed prose, Sagan reveals a jewel-like blue world inhabited by a life form that is just beginning to discover its own identity and to venture into the vast ocean of space.

Economic forces are everywhere around you. But that doesn't mean you need to passively accept whatever outcome those forces might press upon you. Instead, with these 12 fast-moving and crystal clear lectures, you can learn how to use a small handful of basic nuts-and-bolts principles to turn those same forces to your own advantage.

Eating is an indispensable human activity. As a result, whether we realize it or not, the drive to obtain food has been a major catalyst across all of history, from prehistoric times to the present. Epicure Jean-Anthelme Brillat-Savarin said it best: "Gastronomy governs the whole life of man."

Already internationally acclaimed for his elegant, lucid writing on the most challenging notions in modern physics, Sean Carroll is emerging as one of the greatest humanist thinkers of his generation as he brings his extraordinary intellect to bear not only on the Higgs boson and extra dimensions but now also on our deepest personal questions. Where are we? Who are we? Are our emotions, our beliefs, and our hopes and dreams ultimately meaningless out there in the void?

Military history often highlights successes and suggests a sense of inevitability about victory, but there is so much that can be gleaned from considering failures. Study these crucibles of history to gain a better understanding of why a civilization took - or didn't take - a particular path.

All our lives are constrained by limited space and time, limits that give rise to a particular set of problems. What should we do, or leave undone, in a day or a lifetime? How much messiness should we accept? What balance of new activities and familiar favorites is the most fulfilling? These may seem like uniquely human quandaries, but they are not: computers, too, face the same constraints, so computer scientists have been grappling with their version of such problems for decades.

From the best-selling author of Seven Brief Lessons on Physics comes a new audiobook about the mind-bending nature of the universe. What are time and space made of? Where does matter come from? And what exactly is reality? Scientist Carlo Rovelli has spent his whole life exploring these questions and pushing the boundaries of what we know. Here he explains how our image of the world has changed throughout centuries.

Does time exist? What is infinity? Why do mirrors reverse left and right but not up and down? In this scintillating collection, Holt explores the human mind, the cosmos, and the thinkers who’ve tried to encompass the latter with the former. With his trademark clarity and humor, Holt probes the mysteries of quantum mechanics, the quest for the foundations of mathematics, and the nature of logic and truth. Along the way, he offers intimate biographical sketches of celebrated and neglected thinkers, from the physicist Emmy Noether to the computing pioneer Alan Turing and the discoverer of fractals, Benoit Mandelbrot.

Understanding our humanity - the essence of who we are - is one of the deepest mysteries and biggest challenges in modern science. Why do we have bad moods? Why are we capable of having such strange dreams? How can metaphors in our language hold such sway on our actions? As we learn more about the mechanisms of human behavior through evolutionary biology, neuroscience, anthropology, and other related fields, we're discovering just how intriguing the human species is.

Every day of your life is spent surrounded by mysteries that involve what appear to be rather ordinary human behaviors. What makes you happy? Where did your personality come from? Why do you have trouble controlling certain behaviors? Why do you behave differently as an adult than you did as an adolescent?Since the start of recorded history, and probably even before, people have been interested in answering questions about why we behave the way we do.

How will artificial intelligence affect crime, war, justice, jobs, society, and our very sense of being human? The rise of AI has the potential to transform our future more than any other technology - and there's nobody better qualified or situated to explore that future than Max Tegmark, an MIT professor who's helped mainstream research on how to keep AI beneficial.