VII. DISCUSSION. BRIEF CRITIQUE OF "PSYCHO-PHYSICAL PARALLELISM". A DECADE or two ago, the hypothesis commonly known as " psycho- physical parallelism " seemed to have made a permanent capture of the major part of the serious students of man's mental life. More recently some of the recognised authorities in psychology have dissented from its tenets as representing anything like a com- plete and final solution of the problem of the relations of body and mind. This dissent has not been wholly without influence upon the majority. Thus the attitude of mind assumed toward the problem may be said at the present time to divide psychologists into the following three classes : (1) those who still accept the hypothesis of psycho -physical parallelism but, for various reasons, do not choose to re-examine and restate this hypothesis ; (2) those who are indifferent to, or weary of; all discussion of this and similar problems ; and (3) those who regard the entire subject as so profound a mystery that the problem it proposes is essentially and eternally insolvable. In opposition to any of my colleagues who may belong to either of these classes I wish to maintain briefly three counter propositions : (1) The hypothesis of psycho-physical parallelism sorely needs re-examination by its advocates, and it cannot be stated in any form which will satisfy the demands for explanation of the phenomena. (2) Indifference to the problem of the relations of man's body and mind is, both from the theoretical and the practical point of view, inconsistent with the most serious work in psychology. (3) This problem is no more essentially mysterious and insolvable than are all the profounder problems of psychology ; but it is a problem for philosophy to consider, while the scientific psychologist adopts a quite different working hypothesis from that of psycho-physical parallelism. These con- clusions I should wish to establish, did time permit, by a detailed discussion of the following points. 1. All the data for any theory as to the relations of body and mind originate within the unity of the so-called "stream of conscious- ness ". These data consist of occurrences in, or portions of, one experience ; and this experience may be called the conscious life of the mind. In this life, and in accordance with its constitution and
