In 1978, when Michael Hart's controversial book The 100 was first published, critics objected that Hart had the nerve not only to select who he thought were the most influential people in history, but also to rank them according to their importance. Needless to say, the critics were wrong, and to date more than 60,000 copies of the book have been sold. Hart believed that in the intervening years the influence of some of his original selections had...