He adopted Pleo's notion of the anima, or vital prin ciple, which regulates the whole economy of the sys tem. Instead of Plato's three souls, however, he sup poses three spirits, which are the instruments of three faculties, the natural, animal, and vital. The liver is the seat of the natural faculty, which presides over growth, nutrition, and generation ; the vital faculty is placed in the heart, and distributes life and heat through the channels of the arteries; the animal faculty, which resides in the brain, regulates the whole, and, through the medium of the nerves, is made to convey sensation and motion. Besides these, he supposes other inferior faculties, whose office is limited to particular organs ; and these faculties are exactly the same with the rite firoprix, which, though never distinguished till very lately by that name, were, in other respects, as well known to the ancients as the four temperaments.
Of these temperaments, which, as well as the natu val, animal, and vital functions, still make sonic figure in modern pathology, it IN ill now be proper to give some explanation. To account for the original formation of the world out of chaos, the ancient mythologists made use of four elements, fire, air, water, and earth ; and four qualities, hot, cold, dry, and moist. These great agents in nature were found necessary for the explanation of every phenomenon. It was to be expected, therefore, that they should, likewise, be called in to explain the functions of the human body. The lour qualities were accordingly given to four humours,—a kind of secondary elements that were supposed to exist in the body. These, according to Hippocrates, were bile, blood, phlegm, and water; or, as he seems occasionally in clined to think, blood, phlegm, a yellow bile, and a black. To each of these were given two of the elementary qualities ; so that the blood was hot and moist, the phlegm cold and moist, the yellow bile hot and dry, the black bile cold and dry. Besides these, however, Hip pocrates supposed a great many others, particularly the sweet, the salt, the bitter, and the austere. He made, likewise, his humours and qualities to vary greatly in their proportions, and his qualities in their degrees of intensity, and supposed these variations to proceed from an infinite number of circumstances: from difference in age or sex; from the influence of the sun, moon, or planets, in every possible position and aspect ; from the changes of season, and every slight alteration of wea ther. The changes thus arising from the various com
binations, proportions, and degrees, of four humours, and eight qualities, to make no more of them, can easily be shown to amount to, at least, 479,001,600; vet, to practise with sure success, it was necessary to know and distinguish each of these changes. As that, how ever, was impossible, Hippocrates directed his attention chiefly to four changes produced by the varying propor tions of the humours. These changes were called tem peraments; and, according to the humour which pre dominated at the time, they were sanguineous, phlegma tic, bilious, or melancholic. They were limited to four, in order to correspond with the four elements, the four great ages of the world, the four periods in man's lire, the four seasons of the year, and, above all, with the meaning of a mystical word in the language of Pythagoras, signifying a quaternion. It is not surpri sing that Hippocrates should have adopted these fan cies, when we consider the school in which he was edu cated; nor that Galen should, in this respect, have fol lowed a master, for whom lie entertained the highest veneration. But what apology shall be made Mr modern pathologists, who, after entirely rejecting the sense of these ancient writers, would sooner renounce their re ligious creed, than part with the terms in which these antiquated notions are expressed.
From this fantastic pathology let us turn our attention to objects more interesting. The vast collection of his torical, medical, and anatomical knowledge, contained in the works of Galen, arranged with all the nicety of a critic, and adorned by the abilities of the first and most accomplished scholar of his time, impressed the minds of his followers with a kind of reverential awe, which rather checked than excited emulation. For many ages, no person appeared bold enough to dissent from his opi nions, or aspire to equal, far less to excel him. Phy sicians and anatomists sought only to distinguish them selves by their care and industry in studying, abridging, copying., or commenting on, his NV011s',. The- Al who got them into their possession at the taking of A le x andria, followed him with the same implicit deference ; while the translation of the seat or the empire from Rome to Byzantium, and the luture inroads or barbarians, almost extinguished his name in the west. None than a thousand years elapsed from the time of Galen, berme any new discoveries were mode in anatomy, sufliciently important to deserve notice.