a few days after the terrorist devastation of the World Trade Center on September 11, 2001, the wind was from the south. We could smell the burning in my apartment in northern Manhattan. Like most Americans, I felt an overwhelming urge to do something useful. This book is my response to that urge. Though it is based on my career as a professor, this is not a scholarly book in the purest sense. My hope is that the different perspectives I am proposing will appeal not just to specialists but to many different audiences. The four chapters it contains do not add up to a continuous historical exposition, but they all contribute to the idea that the title of the book is intended to evoke: Despite the enmity that has often divided them, Islam and the West have common roots and share much of their history. Their confrontation today arises not from essential differences, but from a long and willful determination to deny their kinship.