Ever since the Renaissance first invented itself some six hundred years ago, there has been no agreement as to what it is. Its definitions have been as many and varied as the legions of scholars who have dealt with it, and the more that is learned about the Renaissance, the less certainty there is as to its extent, nature, purposes, and results. I need not rehearse the labyrinthine story of the idea of the Renaissance; the study of studies of the Renaissance has become a scholarly field in itself; and Professor Ferguson has written the history of the idea of the Renaissance with just the proper mixture of authority, wonderment, and exasperation which it deserves.