Charles W. Bodemer

“ To affirm that Sir Thomas Browne was the founder of chemical embryology or, indeed, to contend that he made a great impress upon the progress of embryology is to humour our fancy. As Browne himself reminds us, "a good cause needs not to be patron'd by a passion." ”

“ Nevertheless, religious faith was only one part of the total faith which Boyle exhibited. He had as much faith in the capabilities, the future progress, and the promise of science as he did in traditional religion. Throughout all his works we see great evidence of his religious piety. But his faith in science, particularly as it affected medicine, we see with utmost clarity in the essay "The Usefulness of Natural Philosophy." He had great vision of the benefits that science would eventually bring to the healing arts. ”

“ Various English embryologists had varying success with developmental theory, but as a group they had made great impact upon the development of embryology. In the course of their century, they had, in the words of one of them, "called tradition unto experiment." ”

“ For even as the studies of Mayow were in progress, embryology was embarked upon a course leading to preformationism. By the end of the seventeenth century, the idea that the embryo was encased in miniature in either egg or sperm was elevated to a position of Doctrine, and thereafter there was little encouragement to quantitative study of development. Many embryological investigations were performed during the eighteenth century, but most relate to the controversy regarding epigenesis and preformationism as the true expression of embryonic development. ”

“ Harvey's treatise on generation is clearly a product of his time. It advances embryology by its demonstration of certain facts of development, by its aggressive espousal of epigenesis and the origin of all animals from eggs, and by its dynamic approach stressing the temporal factors in development and the initial independent function of embryonic organs. ”

“ Digby's general theory thus represents a strange mixture of epigenesis and pangenesis, and is not entirely devoid of "virtues." It is, however, a bold attempt to explain embryonic development in terms commensurate with his time, and it embodies the same optimistic belief that the mechanism of embryogenesis lay accessible to man's reason and logical faculties that similarly led Descartes and Gassendi to comprehensive interpretations of embryonic development comprising a maximum of logic and minimum of observations. ”

“ I would emphasize that Boyle was in essence a man of great faith. He had great faith in religion, and was a deeply religious man. He was a great supporter of so-called "natural religion" and tried to reconcile the doctrines of natural philosophy with those of traditional religion. Westfall [71] has considered in detail the religious attitudes of late seventeenth-century writers, Robert Boyle in particular. The "proofs" alleged by the proponents of natural religion have, of course, little cogency. As Westfall points out, they examined nature in order to find what they already believed. ”

“ But the work is also significant in its espousal of epigenesis, and, supported as his argument was by observation and logic, it became the prime formulation of that concept of development during the seventeenth and eighteenth centuries. His statement of epigenetic development is clear:
In the egg ... there is no distinct part or prepared matter present, from which the fetus is formed ... an animal which is created by epigenesis attracts, prepares, elaborates, and makes use of the material, all at the same time; the processes of formation and growth are simultaneous ... ”

“ This criticism is not so applicable to Highmore, whose theory of development is more vitalistic than Digby's, and is more akin to the concepts developed by Gassendi than those of Descartes. Highmore had experience with the embryo itself, and his actual contribution as an observer of development, although hardly epochal, is worthy of note. But despite this empirical base, Highmore has final recourse to a hypothesis blending many ancient ideas and substituting the Aristotelian material and efficient causes for the "fortune and chance" he objected to in Digby's hypothesis. ”

“ Boyle's medical studies fall into at least two categories. These were the purely physiological experiments, such as those on respiration or on blood, and the more clinical experiments, concerned with [Pg 35] pharmaceuticals, clinical pharmacology, and clinical medicine. The purely physiological experiments have great merit and were profoundly influential in shaping modern physiology. The clinical experiments throw great light on the development of critical judgment in medical history, and the relations of judgment and faith. ”

“ In 1620, Digby's last year of study at Oxford University, Fienus published a work, De Formatrice Foetus, designed to demonstrate that the human embryo receives the rational soul on the third day after conception and to discuss at length such subjects as the efficient cause of embryogeny and the proposition that the conformation of the fetus is a vital, not a natural, action. ”

“ The well-educated physician could always give a logical reason for what he did. The empiric, however, was one who carried out his remedies or procedures without being able to tell why. That is, he could not trace out the logical connection between first principles and the particular case.
Galenism suffered especially from logical systematization, and the system of van Helmont, while far less orderly, also had its own basic principles on which all else depended. Boyle, however, practiced medicine on a thoroughly different basis. ”

“ Boyle, with great enthusiasm, believed that through natural philosophy we would eventually discover "the true causes and seats of diseases" and also find out effective remedies which would quickly free the patient from the disease. [65] But faith and enthusiasm did not compensate for the post hoc propter hoc attitude.
According to Galenic concepts, if diseases are due to alterations of humors either in their quality or in their proportions, then the suitable remedy will restore the appropriate quality or proportion. ”

“ In that obscure world and wombe of our mother, our time is short, computed by the Moone, yet longer than the dayes of many creatures that behold the Sunne; our selves being yet not without life, sense, and reason ”

“ In judging the effectiveness of a remedy or the credibility of a statement, one of the most important weapons was analogy. Direct observation of a phenomenon was good. Next best was direct observation of some analogous phenomenon whereby one [Pg 38] body acted upon another to alter its properties or induce significant changes. Boyle drew his analogies largely from chemistry, but he had no hesitation in applying them to medicine. ”

“ Lett us then confidently conclude, that all generation is made of a fitting, but remote, homogeneall compounded substance: upon which, outward Agents working in the due course of nature, do change it into an other substance, quite different from the first, and do make it lesse homogeneall then the first was. ”

“ As mentioned previously, Boyle felt deeply concerned because physicians tended to ignore the al [Pg 40] leged remedies of those who had not had formal training in medicine. He believed that great specific virtue probably lurked in many of these remedies, and he maintained that the chemists should investigate them without the prejudice that the medical professions exhibited. As part of this view, he felt that "simples" should be more carefully studied, because medicinal virtues inhered in single substances and that complicated combinations were unnecessary. ”

“ Digby argues that the animal is made of the juices that later nourish it, that the embryo is generated from superfluous nourishment coming from all parts of the parent body and containing "after some sort, the perfection of the whole living creature." ”

“ Sometimes, of course, necessity can impose a discipline and rigor which ultimately may serve as a disguised benefit, but in the seventeenth century, when Boyle was active, the lack of systematic training and rigorous background seemed actually an advantage. Clinical chemistry and the broad areas which we can call experimental medicine had no tradition. Work in clinical chemistry, clinical pharmacology, and experimental physiology was essentially innovation. ”

“ He is not content with a verbal or logical solution to a problem, he wants empirical demonstration. Why, he is asking, should we be content with merely a logically correct solution when we can have an experiential demonstration. Try the experiment. Put the logical inference to the test of experience.
This empirical attitude, not at all infrequent in the latter eighteenth-century medicine, was quite unusual in the seventeenth-century medicine. This was precisely the attitude that Robert Boyle exhibited in his clinical contacts. ”

“ Highmore's book is an important one in the history of embryology, since it is the first treatment of embryogeny from the atomistic viewpoint and because it contains the first published observations based upon microscopic examination of the chick blastoderm. Admittedly, the drawings illustrating Highmore's observations upon generation are, to use a word often applied to modern art, "interesting," but they do derive from actual observations of developing plant and animal embryos. ”

“ Here again Boyle keeps an open mind, saying, "and if there be any truth in what hath been affirmed to me by several eye-witnesses, as well physicians as others, concerning the weapon-salve, and powder of sympathy, we may well conclude, that nature may perform divers cures, for which the help of chirurgery is wont to be implored, with much less pain to the patient, than the chirurgeon is wont to put him to." ”

“ What internal and external factors permit a successful breakaway from tradition? Rebels there have always been, yet successful rebels are relatively infrequent. The late seventeenth century was a period of successful rebellion, and the virtuosi were one of the factors which contributed to the success. Robert Boyle played a significant part in introducing new methods into science and new science into medicine.
We must realize that Boyle was primarily a chemist and not a biologist. He thought in chemical terms, drawing his examples from physics and chemistry ”

“ Credulity of physicians, he indicated, may do the world "more mischief" than any other profession, but nevertheless he condemned those who would try to "circumscribe, or confine the operations of nature, and not so much as allow themselves or others to try, whether it be possible for nature, excited and managed by art, to perform divers things, which they never yet saw done, or work by divers ways, differing from any, which by the common principles, that are taught in the schools, they are able to give a satisfactory account of." ”

“ It was not easy in the seventeenth century to avoid falling back upon some variety of cause or force.
In 1651, about two months before publication of Highmore's History of Generation, a work appeared which marks another period in seventeenth-century English embryology. William Harvey, De Motu Cordis almost a quarter of a century behind him, now published De Generatione Animalium, the work he said was calculated "to throw still greater light upon natural philosophy." ”

“ To discuss embryological thought in seventeenth-century England is to discuss the main currents in embryological thought at a time when those currents were both numerous and shifting. Like every other period, the seventeenth century was one of transition. ”

“ He gave in great detail an exposition of how these specifics may operate, but did not in any way produce cogent evidence that they do in fact operate in such fashion.
As a physician, Boyle insisted on facts over theory. He was constantly pleading for physicians to enlarge their experience, to try new medicines, even though these were not based on traditional doctrine. Where observed fact conflicts with theory, the fact cannot be ignored. ”

“ In others, some diffus'd Atomes of this extract, shrinking themselves into some retired parts of the Matter; become as it were lost, in a wilderness of other confused seeds; and there sleep, till by a discerning corruption they are set at liberty, to execute their own functions. ”

“ The same skepticism applies to remedies that, far from being expensive, were common and yet rather disgusting. The use of feces and urine as medication was widespread. The medical virtues of human urine represent, he believed, a topic far too great to be considered in a brief compass. But he declared that he knew an "ancient gentlewoman" suffering from various "chronical distempers" who every morning drank her own urine, "by the use of which she strangely recovered." [59] Boyle was quite skeptical of the reports of others, which he had not had opportunity to try himself. ”