I am indebted for help to the following persons, first among my
friends and colleagues in Oberlin: Andrew Bongiorno, Ernest Bre-
haut, Francis W. Buckler, Edward Capps, Jr., Ellsworth Carlson,
Charles D. Cremeans, Julian S. Fowler, Emma Frank, Lucius Garvin,
James H. Hall, Oscar and Recha Jászi, Frances Keller, William E.
Kennick, Thomas S. Kepler, John C. Lapp, John D. and Ewart
Lewis, Donald M. Love, Herbert G. May, Charles T. Murphy, Rob-
ert D. Murray, Jr., Charles P. Parkhurst, Jr., Helen Senour, Chester L.
Shaver, Wolfgang Stechow, Forrest G. Tucker, Jennie Tucker, Mary
Venn, Clarence Ward, Seldon S. Wolin, and Hermina Zortz; next
to the staff of the Bibliothèque Nationale, Paris, and those of the
Widener and Oberlin libraries; and finally to these scholars of other
institutions: Milton V. Anastos, Dumbarton Oaks Library; Gray C.
Boyce, Northwestern University; Marshall Clagett, University of
Wisconsin; Ernest E. Dawn, University of Illinois; Sydney N. Fisher,
Ohio State University; Erwin R. Goodenough, Yale University;
Henry E. Guerlac, and Charles W. Jones, Cornell University; The-
odore E. Mommesen, Princeton University; John C. Murray, Wood-
stock College; Sidney Painter, Johns Hopkins University; Robert R.
Palmer, Princeton University; Anton C. Pegis, University of Toronto;
Gaines Post, University of Wisconsin; Dorothy M. Quynn, Fred-
erick, Md.; Raymond de Roover, Wells College; Douglas V. Steere,
Haverford College; Anselm Strittmatter, St. Anselm's Priory, Wash-
ington, D. C.; and Harold R. Willoughby, University of Chicago.

The aid I received ranged all the way from helping me to get books
to reading the entire manuscript and proof. Most of the persons listed
read and commented on at least one chapter. I am deeply grateful to
all these fellow-workers. They have saved me endless time and have
rescued me from divers mistakes. The errors that remain are my own.

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