Between 1861 and 1865, the clash of the greatest armies the Western hemisphere had ever seen turned small towns, little-known streams, and obscure meadows in the American countryside into names we will always remember. In those great battles, those streams ran red with blood-and the United States was truly born.

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.

What is life? What is my place in it? What choices do these questions obligate me to make? More than a half-century after it burst upon the intellectual scene - with roots that extend to the mid-19th century - Existentialism's quest to answer these most fundamental questions of individual responsibility, morality, and personal freedom, life has continued to exert a profound attraction.

Philosophers have long puzzled over the nature of space, time, and matter. These inquiries led to the flowering of physics with the Scientific Revolution in the 17th century. Since then, the spectacular success of modern physics might appear to have made philosophy irrelevant. But new theories have created a new range of philosophical concerns: What is the shape of space? Is time travel possible? Is there a grand unified theory that unites all of physics?

Delve into the exciting field of “epistemology”, the philosophical term for our inquiry into knowledge: what it is, the ways we acquire it, and how we justify our beliefs as knowledge. Taught by acclaimed Professor Joseph H. Shieber of Lafayette College, these 24 mind-bending lectures take you from ancient philosophers to contemporary neurobiologists, and from wide-ranging social networks to the deepest recesses of your own brain.