The Physical Dimensions of Consciousness. By Edwin G. Boring.  The Century Co., New York, 1933. Pp.  251.

A reading of this book would indicate that the author was stimulated to its production by a general dissatisfaction with the theories of consciousness which exist, particularly the parallelistic theory and all the difficulties which have been raised by the body-mind problem. He therefore undertakes to determine whether consciousness cannot be thought of in terms of physical dimensions-physical dimensions which evidently he thinks of as being translated into neural functions, and based upon the underlying concept that both the brain and consciousness are fundamentally relational in function. From this point of view discrimination, which is the outstanding characteristic of consciousness, seems to depend upon differentiation, the background of which we must seek in the nervous system. “Consciousness is localized in the brain in the sense that discriminative specificity originates there within the differentiated field that may be imposed by the periphery.” There are four dimensions of consciousness. “Intensity at the more peripheral levels seems to imply total excitation in limited space and time, that is to say, both frequency of impulses in a single fiber and the total number of fibers are concerned. We infer then, not exactly to the space-time summation in the brain before the consciousness can issue, but to a single resultant that is a function of the total excitation in a limited number of adjacent fibers in a limited time. Extensity seems to require for its comprehension spatial organization in the brain”, “Protensity, the durational dimension, must be represented by some terminal event that is specific for the lapsed time and capable of producing a discriminative response. A relativistic interpretation of temporal perception robs it of much of its mystery. Quality, however, presents the greatest difficulties of all. … In respect of hearing, the author inclines to a frequency theory of pitch because of its subsumptive power. In vision it seems as if nothing but a