Islam is one of the world's great religions. Let me be explicit about what I, as a historian of Islam who is not a Muslim, mean by that. Islam has brought comfort and peace of mind to countless millions of men and women. It has given dignity and meaning to drab and impoverished lives. It has taught people of different races to live in brotherhood and people of different creeds to live side by side in reasonable tolerance. It inspired a great civilization in which others besides Muslims lived creative and useful lives and which, by its achievement, enriched the whole world. But Islam, like other religions, has also known periods when it inspired in some of its followers a mood of hatred and violence. It is our misfortune that part, though by no means all or even most, of the Muslim world is now going through such a period, and that much, though again not all, of that hatred is directed against us.