This book is about some topical philosophical and methodological prob-
lems that arise in the study of behavior and mind, as well as in the
treatment of behavioral and mental disorders. It deals with such
questions as 'What is behavior a manifestation of?', 'What is mind, and
how is it related to matter?', 'Which are the positive legacies, if any,
of the major psychological schools?', 'How can behavior and mind best be
studied?', and 'Which are the most effective ways of modifying
behavioral and mental processes?' These questions and their kin cannot
be avoided in the long run because they fuel the daily search for better
hypotheses, experimental designs, techniques, and treatments. They also
occur in the critical examination of data and theories, as well as
methods for the treatment of behavioral and mental disorders. All
students of human or animal, normal or abnormal behavior and mind,
whether their main concern is basic or applied, theoretical or em-
pirical, admit more or less tacitly to a large number of general
philosophi- cal and methodological principles.