Other Pasts, Different Presents, Alternative FuturesWhat if there had been no World War I or no Russian Revolution? What if Napoleon had won at Waterloo in 1815, or if Martin Luther had not nailed his complaints to the church door at Wittenberg in 1517, or if the South had won the American Civil War? The questioning of apparent certainties or "known knowns" can be fascinating and, indeed, "What if?" books are very popular. However, this speculative approach, known as counterfactualism, has had limited