The technical vocabulary of psychology is not in it self an unduly large one, but the older subjects of anatomy and physiology-border upon the psychological field and some knowledge of their terms is also necessary. Thus the technical vocabulary actually used by psychologists tends to be rather extensive. It is the aim of this dictionary, revised in 1964 by Harvey Wallerstein, to give some help, not merely to the layman, but also to the student, in what has now become an important branch of contemporary science.