ABSTRACT
In ancient philosophical systems the study of anatomy and physiology were virtually inseparable. As used by the ancient Greek philosophers, the term physiology originally encompassed inquiries into the nature of living and nonliving things. Eventually, physiological studies were those most closely associated with studies of the vital activities of normal, healthy human beings. Although the activities that distinguish living from nonliving things might be considered more exciting than their morphology, anatomical inquiries could be pursued with only the naked eye and a few simple tools. An understanding of physiological phenomena, in contrast, depends on subtle inferences drawn from chemistry and physics. Nevertheless, many fundamental physiological concepts were formulated by the authors of the Hippocratic texts, the ancient Greek philosophers, and Renaissance scientists. Indeed, for hundreds of years, humoral theory, based on the writings of Hippocrates, Aristotle, and Galen, served as the basic explanation for human health and disease.
