Mental Life: an Introduction to Psychology

Abstract

PSYCHOLOGISTS are faced with the difficult task of clearly distinguishing their field of study, on one side, from philosophy and, on the other, from biology. The domains of other sciences were originally defined in naive, common-sense terms that raised no initial difficulty. On the basis of common experience every one knew what was meant by ‘heat,’ but with its scientific study, unexpected difficulties arose. The ‘caloric’ proved weightless, and ‘heat’ was then described as a mode of motion. The facts of radiation raised fresh difficulty, and theory gave, first, ‘nsensible heat’ and then motion of an immaterial ether. This entailed the difficulty of a kinetic energy from which the term mass had vanished: to be dealt with in turn by recasting the meaning of energy in the light of electro-magnetic theory and the theory of relativity. Still, however, the definition of ‘heat’ presents difficulties which are but evaded in the modern tendency to fall back on some reference to crude introspective evidence and common-sense belief such as: ‘The agent which produces in us certain sensations.’ Mental Life: an Introduction to Psychology. By Dr. B. Edgell. Pp. xvi + 275. (London: Methuen and Co., Ltd., 1926.) 7s. 6d. net.