I just want to ask that in the early times, psychology is defined as the sudy of the soul, later it has been changed to the sudy of the mind and then the study of human behavior. How did it change? who were the persons involve in changing it? Why did it change?

-- Ken Darwin Hermosura (khermosura_8@yahoo.com), June 17, 2001

Answers

There is no simple answer to these questions. The transformation from the study of the soul to the study of the (secular) mind was a gradual process that traversed (approximately) from Descartes to Kant. One especially key figure (but one who gets little "play" in the standard histories) is the German philosopher Christian Wolff, who distinguished between "rational" and "empirical" psychology, a distinction that was picked up in Diderot's classic _Encyclopedia_. Wolff is also the intellectual "lynchpin" between Leibniz and early Kant. After Kant (who believed that psychology could never be a proper science -- see the opening of the _Metaphysical Foundations of Natural Science_), one sees various physicists and physiologists engaging in the scientific study of particular mental functions (most notably perception), rather then "the mind" per se (e.g., Weber, Fechner, Helmholtz). As for the transformation to the study of behavior, John B. Watson is usually credited with this, but there were many people involved in the founding of behaviorism. See, e.g., the introduction to Rob Wozniak's multivolume set on the history of behaviorism. Note also that the definition of psychology as the study of behavior (only) did not ultimately stick. The definition of psychology found in most recent textbooks is considerable broader than this, inculding reference to the mind once again.

-- Christopher Green (christo@yorku.ca), June 17, 2001.