Early in the 1520s Hans Holbein, the great German artist and illustrator, depicted Martin Luther as Hercules Germanicus. In this image the vigorous Luther, clothed in his Augustinian cowl and wielding a deadly club, stands triumphant over several vanquished proponents of Scholastic theology. It is appropriate that Luther should be associated with the mythology of antiquity, since his life and influence have been so susceptible to characterizations of mythical proportions. Champion of German liberties, reviler of the Jews, source of modern High German, seed of dogmatic intolerance, herald of the Protestant Reformation, heretic of the Catholic Church, friend of God and foe of the devil--these and countless other descriptions embrace some aspect of the man. Regardless of personal perspective, however, one would have to judge Luther's efforts in publishing and his literary achievements as truly herculean: from 1516 to 1546 he wrote a treatise nearly every other week--some sixty thousand...