Humours and Degrees.
The doctrine of the "humours," or humoral pathology, as it is generally termed, is usually traced to Hippocrates. It is set forth in his book on the Nature of Man, which Galen regarded as a genuine treatise of the Physician of Cos, but which other critics have supposed to have been written by one or more of his disciples or successors. At any rate, it is believed to represent his views. Plato elaborated the theory, and Galen gave it dogmatic form.
The human body was composed not exactly of the four elements, earth, air, fire, and water, but of the essences of these elements. The fluid parts, the blood, the phlegm, the bile, and the black bile, were the four humours. There were also three kinds of spirits, natural, vital, and animal, which put the humours in motion.
The blood was the humour which nourished the various parts of the body, and was the source of animal heat. The bile kept the passages of the body open, and served to promote the digestion of the food. The phlegm kept the nerves, the muscles, the cartilages, the tongue, and other organs supple, thus facilitating their movements. The black bile (the melancholy, Hippocrates termed it) was a link between the other humours and sustained them. The proportion of these humours occasioned the temperaments, and it is hardly necessary to remark that this fancy still prevails in our language; the sanguine, the bilious, the phlegmatic, and the atrabilious or melancholy natures being familiar descriptions to this day.
The humours had different characters. The blood was naturally hot and humid, the phlegm cold and
