ABSTRACT
PSYCHOLOGISTS who work in the field of classification, whether that of normal or abnormal personality, seldom concern themselves with the history of classification in physics and chemistry. This may be explained in terms of the obvious differences between animate and inanimate matter. However, they also very rarely seem to show any interest in the history of biological classification or taxonomy, and this is rather more difficult to understand because most of the problems which occur in psychology have also been dealt with by biologists and botanists at various stages, and a knowledge of their experiences may be of considerable use in dealing with our own problems.
