From before the days of Moses up through the 1960s, slavery was a fact of life in the Middle East. Pagans, Jews, Christians, and Muslims bought and sold at the slave markets for millennia, trading the human plunder of wars and slave raids that reached from the Russian steppes to the African jungles. But if the Middle East was one of the last regions to renounce slavery, how do we account for its--and especially Islam's--image of racial harmony? How...