Harvey's Views on the Use of the Circulation of the Blood

by John Green Curtis

And a little farther on:—

"For there exists in the semen of all [animals] that which makes their semen generative, the so-called heat. Yet this is not fire, nor any such power, but the spirits[319] included in the semen and in foaminess, and in the spirits the nature which is analogous to the element of the stars."[337]

That generative heat which is not elemental fire, but a "body" or "nature" diviner than the lower elements, can be the analogue of nothing else than the celestial ether.

What led Aristotle to so lofty a flight of speculation? He does not tell. One may guess, however, that it may well have been this: that he had found himself obliged not only to deny the identity of the generative heat of the semen with elemental fire, but also to deny the identity with elemental fire even of the glowing sun, as well as of the other planets and the fixed stars; and to maintain that all the heavenly bodies consist of ether. These denials we have read already; they shall presently be commented on. Taking them for granted: now, since the life-giving sun is not elemental fire but ether, would not the life-giving seminal heat, which also is not elemental fire, naturally be the analogue of the ether? "Man and the sun generate man," said Aristotle, in a famous passage.[338] He needed no knowledge of chlorophyll to teach him this. The ether is the element of the sun, moon, stars, and spheres; of it consist the bodies associated with the souls of the living, unalterable, immortal, divine existences of the eternal heaven. To associate a body analogous to this ether with the dormant soul of a living existence—a living existence alterable and mortal as an individual, but one of an immortal race—in the medium which shall maintain that racial immortality by begetting a new individual out of the lower elements—this is a stroke characteristic of the man who declared that "the race of men, and of animals, and of plants, exists forever";[339] the man who assigned to every bloodless animal an analogue of the blood and an analogue of the heart,[340] to the octopus, an analogue of the brain;[341] the man in whose eyes the heavenly bodies were divine living existences running eternal courses and so, we may presume, were analogous in some degree to the living existences of the earth.[342]

Harvey in one of the earlier Exercises of his treatise On Generation had already followed the ancient master's footsteps in this matter. Discoursing of the endless succession of generations the pupil says that this

"makes the race of fowls eternal; since now the chick and now the egg, in an ever-continued series, produce an immortal species out of individuals which fail and perish. We discern, too, that in similar fashion many lower things rival the perpetuity of higher things. And whether or no we say that there is a soul in the egg, it clearly appears from the cycle aforesaid that there underlies this revolution from hen to egg and from egg again to hen, a principle which bestows eternity upon them. That same, according to Aristotle,[343] is analogous to the element of the stars; and it makes parents generate, makes their semen or eggs prolific, and, like Proteus, is ever present."[344]

Let us return now to Harvey's polemic. In it he does not give chapter and verse by which we can properly verify more than a few of his statements of the views of "Scaliger, Fernelius, and others"; but the words of Aristotle which Harvey quotes go far to justify his intimation that the views which he states and combats, as the champion of the circulating blood, are largely derived from those Aristotelian words—whether by misinterpretation, as he roundly but indefinitely declares, or with deliberate modification of doctrine, need not now concern us.

At the very outset of Harvey's discourse about the innate heat, the first doctrine that he reprobates is a striking one, viz.: that the innate heat is one and the same thing with spirits distinguishable from the blood, though not separable from it. Of these spirits he stoutly denies the existence, on the true scientific ground of lack of all evidence from observation in their favor. Our earlier studies of ancient doctrines of respiration have brought before us, as supposed to exist in the blood, spirits variously styled "elemental," "aërial," "nourished by our common and elemental air," "nourished and increased from the thinner part of the blood." We have even read Galen's words of spirits which are "the soul's most immediate instrument," viz.: the "animal spirits" in the brain and nerves. Indeed, during the eighteen centuries between the death of Aristotle and the boyhood of Fernelius and Scaliger, the word "pneuma"—"spirits" or "spirit"—did most varied duties in the service of physicians, philosophers, alchemists, and theologians; and this same word is of great importance in the scriptures.[345] It is noticeable that, although Harvey rejects the doctrine of spirits in the blood, even he himself talks of the blood being itself spirits.[346] This fact, however, should not militate against him or lead to confusion. The word "spirits" being a very comprehensive technical term of his day, he does not refuse to employ it as a label for qualities of the blood after he has denied the very existence of what is properly denoted by the word "spirits." He simply behaves as we behave when we talk of the "sympathetic" nerves, though the theory is exploded which the adjective expresses; or when we speak of "animal cell," well knowing that no proper wall necessarily surrounds the living substance.

Despite the protean forms of the spirits it is not till we have reached Harvey's Exercise On the Innate Heat that we have fallen in with spirits in the blood which, for some of his predecessors, "constitute an innate heat more excellent and more divine, as it were"; nor with "a spirit, another innate heat, of celestial origin and nature." For this treatment of spirits within the blood and of innate heat, as convertible terms, the way may well have been paved by the words in which Aristotle intimates that the generative heat of the semen resides in the spirits therein, i.e., in hot vapor produced within the body of the male and included within the films of foam-bubbles in the semen. Referring to "the so-called heat" the words of Aristotle are: "Yet this is not fire nor any such power, but the spirits included in the semen and in foaminess, and in the spirits the nature which is analogous to the element of the stars."[347] The transition can hardly have been too difficult from the view of Aristotle that in the spirits of the semen is heat which is not elemental fire, to the view combated by Harvey that the spirits of the blood are heat which is not elemental fire.

Aristotle's striking biological doctrine that the generative seminal heat is a "nature which is analogous to the element of the stars" appears to be an obvious source of those seeming fantasies, written down eighteen centuries later, at which Harvey girds when he says: "For what we so commonly would fetch from the stars is born at home." If we use our judgment simply, upon Harvey's statement of their opinions, the men whom he castigates, having strayed from the ancient master's footsteps by making the spirits one and the same with the innate heat instead of the vehicle thereof, next stray still more blindly by identifying this heat, alias these spirits, not with an analogue of the ether, but with a portion of the ether itself. Therefore is it that we read in the words of Harvey's polemic, of "that foreign guest, ethereal heat"; of those spirits "aërial or ethereal, or composed of substance both ethereal and elemental"; of spirits "which draw their origin from heaven" and elicit Harvey's ironical wonder that they "should be nourished by our common and elemental air." Therefore, too, is he able to tell us of that amazing spirit, alias innate heat, which is "a body" and qualified by many imposing adjectives and finally styled "ethereal and sharing in the quintessence." The doctrine of Aristotle that in the semen there are spirits which are the vehicle of generative heat which is analogous to the element of the stars, is a baseless doctrine, but it is a subtle and far-reaching speculation. The doctrine stated and attacked by Harvey that in the blood there are spirits which are the innate heat, which consists as a whole or in part of the element of the stars, is not only a baseless doctrine, as Harvey vigorously shows, but certainly is lame as speculation despite its glittering appeal to the imagination. To make spirits and innate heat convertible terms may pass as but one among many phases of speculation. But to bring down actual ether from heaven to earth, although attempted by eminent thinkers[348] centuries before Scaliger and Fernelius, is to bring chaos into that conception of the universe which requires the "first element" to revolve forever on high, above that lower world which lies beneath the sphere of the moon. To Aristotle such chaos surely would have been abhorrent; indeed, it runs counter to his expressed description of the ether.[349] Moreover, Aristotle's application of the term "analogue" to the generative heat is equivalent to a denial that the generative heat is actually ether; for analogues do frequent service in his doctrines and he explicitly states the analogue of a thing to be something different from the thing itself.[350] What that mysterious analogue of the ether may be with which the generative heat is identified we are not explicitly told, as we are not told what the analogue of the heat may be in bloodless animals. We are left to judge for ourselves after deeper investigation of nature or deeper study of the Aristotelian writings. Had Aristotle been ready to define and describe the body which is more divine than the four lower elements, but is not the first element on high, he probably would not have chosen an analogue as the fittest vehicle for his thought.