If you ever visit Florence-and you really ought to see the birthplace of the Renaissance-there is a fascinating little museum, next to the more famous Uffizi, devoted to the history of science. There you can see one of Galileo's original telescopes, as well as a fascinatingly grotesque and revealing artifact: one of Galileo's fingers, preserved in an elaborately decorated container of the style used for holy relics belonging to the Church. Legend has it that this is his middle finger-a fitting message for Galileo to send to the Church that persecuted him. That relic sums up the contradictions of Galileo's...