Page:Popular Science Monthly Volume 86.djvu/598

594 progress attained in reading its meaning; the ideal "has always to grow in the real, and often to seek out its bed and board there in a very sorry way" (Carlyle).

The ancient and honorable place of the doctrine of the temperaments in the evolution of psychological knowledge warrants its further consideration. Most influential were the contributions of Galen (. 130-200), who developed the views of Hippocrates and whose authority dominated the medical world for centuries. The doctrine became a classical heritage through its incorporation in the Galenic system of medicine. Its survival in the transfer of Greco-Roman science and tradition across the desert of unprogressive ages, with their uncertain and irregular caravans of learning, was due largely to its association with the "humoral" theory of disease. This remained a central as well as a controversial issue in medieval and renaissance medicine, and was effectively retired only by the complete transformation of physiological conceptions inaugurated by Harvey’s discovery of the circulation of the blood (1628). Along with this decisive reform in knowledge and method there was established the clinical temper of the practise of medicine, which was as largely set by Sydenham (1624-1689), as were the experimental standards by Harvey, as similarly the anatomical prerequisite had been supplied by Vesalius (1514-1564). Cumulatively these advances served to cast off the spell of Galen and to install verification and observation in place of authority. As a herald of the new learning, the philosopher John Locke, a friend of Sydenham’s, wrote:

These considerations show to what extent practises kept alive systems precariously supported by principles. Symptoms such as fevers and chills, parching and perspiration, substantiated the hot and cold, the dry and moist as clinical realities. Remedies were prescribed to counteract them, diets were arranged according to degree of dryness and moisture. Even when the classic doctrines were discarded, they were replaced by others developed in like manner.