EDWARD L. THORNDIKE

PROFESSOR OF EDUCATIONAL PSYCHOLOGY
TEACHERS COLLEGE, COLUMBIA UNIVERSITY
NEW YORK

THE MACMILLAN COMPANY
1919

All rights reserved
Copyright, 1912,
By THE MACMILLAN COMPANY.
Set up and electrotyped. Published June, 1912.
Norwood Press
J. S. Cushing Co.—Berwick & Smith Co.
Norwood, Mass., U.S.A.