Even the idlest stroll through Cambridge, England, calls to mind a pantheon of great scientific minds, but none is greater than Isaac Newton, who revolutionized the world of “natural philosophy” while the rest of England was paralyzed by the plague. Reading an enlightening new biography by Peter Ackroyd, Christopher Hitchens learns that Newton probably didn’t get bonked on the head by an apple—but he did have some pretty funny ideas about sex, gold, and religion.