ABSTRACT
Of ancient origin, indeed, are the attempts to solve the problem of types. It has been sought, on the one hand, to bring together into definite categories the manifold differences of human individuals, and on the other to break through the apparent uniformity of all men by a sharper characterisation of certain typical differences. Without caring to go too deeply into the history of the development of such attempts, I would like to call attention to the fact that the oldest categories known to us have originated with physicians, most especially with Claudius Galen, the Greek physician who lived in the second century after Christ. He distinguished four fundamental temperaments, the sanguine, phlegmatic, choleric and melancholic. But the basic idea of this differentiation harks back to the fifth century before Christ, to the teachings of Hippocrates, who described the human body as composed of the four elements, air, water, fire and earth. Corresponding to the elements there were to be found in the living body, blood, phlegm, yellow and black bile; and it was Galen's idea that by reason of the unequal admixture of these four factors, men could be separated into four different classes. Those in whom blood predominated were sanguine; those having relatively more phlegm were designated as phlegmatic; when yellow bile prevailed the temperament was choleric; and those under the sway of black bile were melancholic. As our modern speech attests, these differentiations of temperament have become immortal, although their naïveté as psychological theory has long since been apparent.
