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.

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.

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.

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.

歴代中国王朝が鋳造した数千億枚に上る銅銭．世界史上極めてユニークなこの小額通貨は，やがて海を越え，日本を含む中世東アジアの政治・経済・社会に大きなインパクトをもたらした．銅銭はなぜ，各国政府の保証なしに商取引の回路を成り立たせてきたのか．