The focus of this paper is a fascinating but hitherto unstudied 1742 manuscript treatise by Johannes Daniel Schlichting (1705–1765) titled “Sapientiæ Problema” that contains something extremely rare in the mid-eighteenth century: a full-blown speculative cosmogony. As this article reveals, Schlichting developed a distinctive vital liquid matter in an effort to account for the generation of all natural bodies and combat the stamina-based theories that were dominant in his day. He hoped that his treatise would be published in the Philosophical Transactions of the Royal Society, but an accompanying abridgment by the FRS Henry Baker (1698–1774) strongly implies that Schlichting’s speculative bent and desire to divulge causal explanations were unacceptable to the Englishman and generally ill-suited to the intellectual climate of mid-century England.
This article explores and situates a fascinating but hitherto unstudied manuscript treatise titled “Sapientiæ Problema” [“A Problem of Wisdom”], which contains something extremely rare in the post-Cartesian and post-Newtonian world of the mid-eighteenth century: a non-mechanistic, universal matter theory. The author of this piece, which is housed in the Royal Society Library at L&P/1/151, is Johannes Daniel Schlichting (1705–1765), a virtually unknown physician from Friesland who set up shop in Amsterdam. Schlichting published on a spectrum of physiological and anatomical topics, inspired experiments that fuelled Albrecht von Haller’s case for irritability, and was honored as an “associé éstranger” of the French Académie Royale de Chirurgie and a fellow of the German Academia Naturae Curiosorum. Alongside the treatise itself sits “Some Account of Dr John Schlichting’s Latin Manuscript on the Generation of Seeds” by the renowned FRS, microscopist, and teacher of the deaf, Henry Baker (1698–1774). As shown by a notation on the last leaf of his manuscript, Schlichting finished and dispatched “Sapientiæ Problema” on 16 September 1742. But the dates in Baker’s hand on the title page of the Latin manuscript and the final leaf of his English précis indicate that his abridgment was not composed until 20 January 1743, and (as we will see) it was probably read at a Royal Society meeting shortly thereafter.
While Schlichting’s treatise provides powerful insights into the concepts and experiments that a mid-century thinker could summon to develop a sophisticated matter theory, Baker’s digest strongly implies that such wide-reaching natural philosophical visions were not always welcomed with open arms at this notoriously cautious moment in the history of science. Being mostly unconcerned with human beings, let alone human health, “Sapientiæ Problema” is altogether unlike the preponderance of Schlichting’s output, and, indeed, the bulk of papers published in the journals of learned scientific societies at the time, which tended to dwell on highly particular natural historical and medical matters. Since the articles in these journals have had a disproportionate bearing on understandings of eighteenth-century scientific developments (especially in England), it is often assumed that natural historical (and occasionally experimental) approaches all but superseded speculative ones.1 But “Sapientiæ Problema” is impervious to such a divide. Along with demonstrating his immersion in the history of philosophy, chymistry, and medicine, Schlichting called upon experimental data on topics ranging from the coagulation of blood and fiber formation to the multiplication of cells and the generation of seeds to forge a unique vision of nature according to which a vital liquid matter, or a “liquidam seminis materiem,” underlay all natural functions (Schlichting 1742c, f. 28v).
When it comes to the history of eighteenth-century science and medicine, attention has been divided between two quite separate domains: the “organic vitalism” associated with physicians at the University of Montpellier, on the one hand, and the growth of practical, proto-industrial chymistry, on the other.2 But neither of these discourses is especially helpful for unraveling and contextualizing the cosmogony of “Sapientiæ Problema.” More relevant is research on the disputes between proponents of preformation (the outlook that an animal is formed from the moment of insemination) and epigenesis (according to which a body takes shape part-by-part over time) that resurfaced with a vengeance in the early eighteenth century. These debates are principally associated with Haller, Caspar Friedrich Wolff, Jan Swammerdam, Nicolas Malebranche, and Pierre Louis Maupertuis, and tended to revolve around animal generation and particularly experiments on chick embryos.3 Even as Schlichting drew upon such discussions, however, his principal concern was with the equally pressing problem of material “pre-existence,” and specifically the stance that God created countless invisible stamina at the beginning of time.4 During Schlichting’s day, stamina were usually portrayed as compact bundles of elastic fibers (with the Latin “stamina,” which is the plural of “stamen,” signifying “warp threads”) and these were importantly thought to contain living bodies in miniature.5 While this concept has all too often been overlooked—despite its close ties to the well-studied issue of preformation—deliberations about stamina were indispensable to late seventeenth- and early eighteenth-century ideas about matter, generation, and life, and preoccupied figures no less central to the history of science and philosophy than Marcello Malpighi and Gottfried Wilhelm Leibniz.
As this article reveals, the principal aim of “Sapientiæ Problema” was to afford an alternative to stamina theories that could not only explain the generation of animals and vegetables but also minerals, metals, and even mountains. With his liquid matter, Schlichting challenged, in one fell swoop, both the virtual consensus that stamina spawned all living beings, and the notion that irreducible solids (whether atoms, particles, or corpuscles), which had fascinated seventeenth-century philosophers and medics, and which were of continued interest in his own day, were the fundamental building blocks of nature.6 The generative powers that Schlichting imputed to his liquid and its universality are all the more remarkable given that “Sapientiæ Problema” was geared towards an English audience nearly three-quarters of a century after John Locke had denied, in his hugely influential 1689 An Essay Concerning Human Understanding, that humans could fully determine the nature of fundamental substances.7
To begin, this article outlines Schlichting’s biography and intellectual contributions, focusing on the works that he produced as a city physician, and on his connections to the burgeoning scientific societies of his day. It then turns to the liquid cosmogony expounded in “Sapientiæ Problema,” roughly following the progression of the manuscript. As such, it commences with an evaluation of his nineteen “postulata”—which are situated in relation to atomic and chymical developments—and then moves onto Schlichting’s broader questions and conclusions. I display that in these latter parts of the treatise he not only summoned his fundamental liquid to account for the radical geological transformations that the Earth had undergone over its supposedly 5,000-year history, but also to devise a rather late defense of spontaneous generation, based in part on an ingenious analysis of the proliferation of vessels. Finally, I pivot to Baker’s notes on “Sapientiæ Problema,” which offer a unique window into the Anglicization of Latin natural philosophical vocabulary, and, more generally, the shifting complexion of natural investigations in and around the Royal Society.
By unearthing Schlichting’s cosmogony, I ultimately hope to shed light on a rare mid-eighteenth-century attempt to explain the natural world neither through the lens of natural history nor mathematics, but rather through a gradual progression from universal axioms to generalized causal conclusions grounded in specific experimental results. I also argue, however, that this sophisticated but increasingly uncommon approach might be the key to explaining why Schlichting’s theory never saw the light of day.8
2. The Vocation of a Learned Physician
In extant historiography on eighteenth-century natural inquiries, the vocational expectations and contributions of learned city physicians like Schlichting have been almost completely overlooked for a mixture of social and intellectual reasons. Most significantly, scholars have tended to foreground two divergent enlightenment “types”: those who embroiled themselves in collaborative, incremental, and ostensibly egalitarian natural historical projects and “geniuses” or celebrity professors like Isaac Newton and Herman Boerhaave who made paradigm-shaping discoveries and attracted countless disciples.9 To properly appreciate the content and significance of “Sapientiæ Problema” as well as Schlichting’s wider medical and philosophical insights, it is therefore essential to sketch out his biography and intellectual aims.
Born to a Lutheran minister in Wadern on 23 January 1705 and raised in Jever, the capital of Friesland, Lower Saxony, Schlichting first surfaces in Groningen in 1730. It was here that he defended his doctorate in medicine with a thesis on “lacte,” an expansive term that not only signified animal milk, but also chyle and plant sap.10 In his dissertation, Schlichting exhibited his already capacious knowledge of both practical and theoretical medical developments, quoting at intervals from major physicians of the previous century including Daniel Sennert and Walter Charleton along with contemporaries such as Georg Ernst Stahl and Boerhaave. While the questions that he addressed are predominantly anatomical and physiological—how is milk produced? Is it healthy for human consumption? Does it circulate in the body? How is it digested?—this youthful piece laid the groundwork for “Sapientiæ Problema” perhaps more than any of Schlichting’s subsequent ones, both in terms of its sources and its focus on the character and significance of a liquid.
Upon completion of his doctorate, Schlichting resettled in Amsterdam as a physician, where he edited several books on surgery, most notably the 1734 redaction of Het nieuw hervormde examen van land- en zee-chirurgie [“The newly revised exam of land and sea surgery”] by the Dutch surgeon Johannes Verbrugge.11 This best-selling handbook, which was republished throughout the eighteenth century, was intended to help would-be surgeons for the Dutch East India Company pass the qualifying exam. In the same year, he also provided an introduction to the second edition of the Dutch translation of a work on surgery by the French physician, Joseph de La Charrière, titled De nieuwe operatien der chirurgie. It was in recognition of these efforts that Schlichting was made a member of the Academia Naturae Curiosorum on 25 April 1740 (Jacob von Siebold 1787, pp. 299–300).
Each member of this illustrious German society—which had been restricted to learned medics until the successive reforms of 1677 and 1687—was allocated the name of a seemingly appropriate ancient Greek natural philosopher, physician, or mathematician (Müller 2008, p. 255). Given the sheer quantity of members by the mid-eighteenth century (Schlichting was the 500th) and the prohibition on name replication, the available titles had become rather obscure by the time that Schlichting was admitted. Thanks to his proficiency in surgery, however, he was eventually dubbed Nymphodorus II, with reference to the third century BC Greek physician who invented a machine for realigning dislocated bones (Büchner 1755, p. 508). To mark his admission to the Academia, Schlichting produced a popular Dutch volume in 1740 with the Latin title of Syphilidos mnemosynon criticon [“A Critical Theory on Syphilis”], which was republished in 1746 and 1755. Despite the fact that this vernacular book on the causes and cures of syphilis was intended for a local audience of medics or even patients, it further betrayed his conversance with ancient and modern natural philosophy. Providing a potted history of syphilis in the preface, Schlichting drew attention to the contributions of Protagoras, Hippocrates, Democritus, and Epictetus, among others, and laid bare his methodological debts to prominent moderns such as Jan Baptiste van Helmont, whom he praised for his promotion of observation-based medicine, as well as Leibniz and Christian Wolff, whose convictions that everything has “cause and reason” (the so-called “principle of sufficient reason”) he admired (Schlichting 1746, “Voorreden,” *8–9 and **6–9). As we will see, both the particular chymical insights of van Helmont and the traditional causal approaches of Leibniz and Wolff had a lasting impact on Schlichting’s thought.
Even though Schlichting penned several widely read monographs over his career, he preferred to communicate his observations and ideas through nascent natural philosophical journals. It is well known, in this regard, that a handful of distinguished, longstanding, and society-affiliated periodicals were founded in the seventeenth century including the English Philosophical Transactions of the Royal Society (first issued in 1665), the French Mémoires de l’Académie Royale des Sciences (first issued in 1666), and the German Acta Physico-Medica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosorum, which began in 1670 as the Ephemeriden or Miscellanea Curiosa.12 Despite their miscellaneous complexions, these prestigious forums for scientific exchange showcased some of the most consequential medical and natural philosophical innovations of the late seventeenth and early eighteenth centuries. To offer a particularly striking example, the Dutch cloth merchant turned prodigious naturalist, microscopist, and FRS Antonie van Leeuwenhoek was such a regular fixture in the Transactions for half a century—from 1673 until his death in 1723—that he found it unnecessary to publish anywhere else. But whereas Leeuwenhoek was dedicated to one journal, Schlichting seems to have been ahead of the curve in distributing pieces to all of the above.
As a member of the Academia Naturae Curiosorum, the only journal to which Schlichting was obliged to contribute was the Acta Physico-Medica (though, even then, not all members adhered to this lege) (Mücke 2013, pp. 186–8). His earliest articles appeared in the sixth volume of 1742, which is the first that was printed after his admittance. One of the most consistent contributors during the 1740s, he provided eight short “observations” in 1742, and added five further items to each of the subsequent volumes of 1744 and 1748 (Schlichting 1742a, 1744a, 1748). Some of the more noteworthy are “Noxa potulentorum calidorum” [“The harm of hot drinks”], “Anchylosis humerum inter & homoplatam” [“On chylification between the humerus and the shoulder blade”], and “Singularibus quibusdam phænomenis, manifesto demonstrantibus, omne virus rabidi animalis primum partes salivales adsicere” [“A singular phenomenon that provides a manifest demonstration that the primary part of the saliva of every poisonous, rabid animal is dried”]. While Schlichting’s thesis and the foreword to Syphilidos mnemosynon criticon paint a clear picture of a philosophically-attuned physician—and his comments on dried saliva even had a bearing on his later cosmogony—these brief entries are utterly devoid of historical or theoretical reflections. Yet such specific notes were fully suited to this journal and of a piece with pan-European trends. As Lorraine Daston has demonstrated, the seventeenth century saw a massive spike in appeals to “observation,” usually to denote singular events witnessed firsthand by a named author. This practice peaked around 1750, and was perhaps most pronounced in the Acta Physico-Medica.13
When read in relation to these granular observations, Schlichting’s decision to compose, and submit to the Royal Society, his far more speculative “Sapientiæ Problema,” which only called on experiments to bolster a general hypothesis, is all the more striking. He did not launch himself onto the English scene with this paper alone, however, but instead made the prudent decision to package it with a highly particular physiological article, rather pompously titled “Observationes variœ medico-chirurgicœ a Johanne Daniele Schlichting, Med. & Chir.[urgiae] Doctore, Acad.[emiae] Cæsareo-Leopoldin. Nat.[urae] Curios.[orum] Membro, & Commercii Literarii Norimberg. Socio” (Schlichting 1743). As this catalog of accolades signals, Schlichting took the utmost advantage of his newly acquired status as a member of the Academia Naturae Curiosorum, also putting these institutional affiliations front and center of an austere 1748 portrait (see Figure 1). But the subtitle of the article, which was dispatched from Amsterdam on the same day as “Sapientiæ Problema” (16 September 1742) yet read before the Society slightly earlier (on 23 December), was the far more precise one of “Circa Spinam Ventosam Animadversa nuper decta” [“Some observations lately made upon a Spina Ventosa”]. Schlichting’s paper, as this indicates, is actually a painstaking study of “tuberculous dactylitis,” or a skeletal manifestation of tuberculosis that usually affects young children, and it chiefly consists of a description of the symptoms of a woman and a child whom he treated with the disease, along with some remedies for reducing the size of abscesses.
Schlichting’s article in the Transactions shares many features with his earlier ones, and his proposals for abscess reduction in fact resemble those from his contemporaneous submission to the Acta Physico-Medica titled “Injectionum, ex Essentia Myrrhæ paratarum, insigni utilitate in Empyemate & Hepatis abscessibus” [“Injection, prepared out of the essence of myrrh, is of manifest utility in empyema and a hepatic abscess”] (Schlichting 1742a, p. 115). His piece for the Transactions, however, was longer and more sophisticated than the related one in the German journal, and the manuscript copy even includes figures. One of these was printed by C. de Putter and depicts the “Vagina Uteri” while the other two are of a diseased thigh and arm respectively and were “roughly drawn by the Surgeon himself” (Schlichting 1742b, f. 6r). The fact that his article blends in seamlessly with others in the English periodical, while being considerably more elaborate than most that appeared in the Acta Physico-Medica, suggests Schlichting’s acquaintance with the format of the Transactions.14 This is not particularly surprising since the minimal overlap in personnel between the two societies had long been offset by plenty of mutual interest and cross-publication among affiliates. In the late seventeenth century, for example, the major treatises of the FRS and renowned botanist Nehemiah Grew were translated into Latin for publication in the Miscellanea Curiosa, while, in the mid-eighteenth, the English dissenting minister and FRS Henry Miles compiled an inventory of early copies of the “Miscellanea Curiosa” almost certainly out of a desire to assess and purchase those that the Royal Society lacked.15 Schlichting’s contribution to the Transactions only further substantiates this picture of continued cross-societal engagement.
But of all of Schlichting’s articles, the most influential, in the end, seems to have been a 1744 paper published in neither the German nor the English journal but rather in the Académie des Sciences’s Mémoirés de Mathématique et de Physique de l’Académie Royale de Paris. Titled “De motu cerebri,” this piece divulged the view, for the first time, that respiration is synchronized with the motion of the brain (Schlichting 1744b). Crucially, Schlichting’s hypothesis prompted Haller to conduct systematic experiments on the subject, which proved indispensable in his attempt to distinguish sensibility from irritability in his celebrated 1753 De partibus corporis humani sensibilibus et irritabilibus.16 At the outset of this book, Haller noted that “Schlichting has said, that there was a motion in the brain, that is ascended and descended alternately, and is extremely angry with those who rank it [the brain] amongst those parts of the body which are void of motion” (Haller 1755, pp. 20–2; also see Steinke 2005, p. 82). Proceeding to dissect several “dogs, goats, rats, frogs, cats, and other animals,” Haller was surprised to discover that the brain indeed “ascended in expiration and descended in inspiration.” Rather than proving that this held true for the brain of a living animal, however, he concluded that “Neither the dura mater nor the brain have any motion unless the cranium is removed.” As Haller alleged, the process of detaching the cranium during a dissection destroyed the dura mater (or the thick membrane surrounding the brain), which triggered the apparent movement. In his endeavor to isolate the cause of irritability, he went on to argue that the swelling of veins impels the circulation of the blood, and that vessels transmit this pressure to an otherwise inactive brain. While “Sapientiæ Problema” again differs starkly from Schlichting’s anatomical writing, his contentions about the vital motions of the brain, with their bearing on irritability, were interventions into one of the eighteenth-century physiological debates with the widest-reaching implications.
Having contributed numerous significant pieces to learned journals, Schlichting had a final publishing burst in the late 1740s. In 1747, he released a monograph, adorned with elaborate illustrations of the uterus, that detailed the safest ways to extract a dead fetus from the womb, titled Embryulcia nova detecta, which was swiftly followed in 1748 by his Traumatologia nov. antiqua, a treatise on the theory and practice of surgery. While he does not seem to have published any further books or articles, Schlichting returned to editorial tasks, penning prefaces for volumes such as the 1750 Dutch translation of a surgical dictionary by the German physician Caspar Schröter titled Chirurgicaal lexicon of woordenboekje, and a 1751 text by the Amsterdam doctor Cornelis Plevier, De gezuiverde vroedkonst [“The purified midwifery”]. After these appeared, he fell off the scene, though he did not pass away until 22 August 1765 (DTB archieven, archiefnummer 5001, Inv. nr. 1135).
Schlichting’s permanent retreat from public life may well have been the consequence of a controversy that he became embroiled in with two young Dutch surgeons, Abram Titsingh and David Eckhard, the latter of whom ferociously attacked him in 1748 for his invasive surgical practices and especially his recourse to amputation with Goliath, of anders den heer doctor Schlichting, in zijn onlangs uitgegeven libel handelende over de wonden, naar ’t leven afgebeeld [“Goliath, or else Mr. dr. Schlichting in his recently published libel about the wounds depicted after life”]. It does not appear to have helped much that two other surgeons, W. Uwens and G. Calleree, took up cudgels for Schlichting a year later in De eer en het chirurgicaal onderwys van Johannes Daniel Schlichting … tegens de infame lasteringe van de chirurgyns Abram Titsingh en David Eckhard hard verdedigt [“The honor and surgical education of Johannes Daniel Schlichting strongly defended against the infamous slander of the surgeons Abram Titsingh and David Eckhard”]. Schlichting was evidently regarded in his day as a “Goliath” of eighteenth-century surgery, though his critics rather unfairly meant by this that his methods made him as much a philistine as a giant among physicians.
With the proliferation of societies (populated by physicians) and journals, it had become increasingly incumbent upon learned medics like Schlichting not just to produce occasional anatomical or physiological monographs but also to make their case studies public in newly established print forums. Yet whereas a previous generation of medically-trained individuals—including those such as van Helmont, Charleton, and Grew who lacked university posts—made cutting-edge natural philosophical interventions and developed matter theories that had little bearing on their daily medical preoccupations, such efforts were gradually swept aside and sometimes even frowned upon as unduly ambitious by the time that Schlichting produced “Sapientiæ Problema.” In light of this, his most theoretical output is perhaps best viewed as an attempt not only to formulate a convincing universal matter theory but also to keep alive an earlier set of vocational expectations and objectives that were precipitously vanishing.
3. Postulating A Liquid Cosmogony
Schlichting in all probability sent “Sapientiæ Problema” to the Royal Society out of a desire to have it read at a meeting and printed in the Transactions. At least historically, the Transactions had published slightly longer and less practically-orientated papers than the Acta Physico-Medica. On the level of style alone, however, Schlichting’s enumeration of postulates that are continually referenced as the treatise proceeds was virtually unprecedented among papers that were read before the Society or that appeared in its journal, being far more common in academic natural philosophy textbooks (see Anstey 2017, pp. 9–11). While he possibly hoped that the editors would make an exception for his piece, it is just as likely that he was unaware of the extent to which the Transactions had come to orbit around particular medical, natural historical, and antiquarian subjects by the mid-eighteenth century, especially under the presidency of Martin Folkes (1741–52) (Sorrenson 1996, p. 37). Tellingly, when “Sapientiæ Problema” alludes to the ideas of figures who featured in this journal, it is generally to seventeenth-century ones, from Leeuwenhoek to the Scottish divine George Garden, whose conceptual and experimental orientations were closer to Schlichting’s own.
Consisting of thirty carefully organized pages, “Sapientiæ Problema” commences with a series of “postulata” (the focus of this section), then provides the extremely general thesis statement that seed generation is infinite and eternally the same, and finally pivots to a set of questions and conclusions about both generation and the nature of liquid substance, interspersed with examples and experiments.17 In spite of its conventional format, the subtitle of the treatise—“de seminum genesi” [“generation of seeds”]—already signposts its polemical bent. Within the atomic tradition, “atomos” and “semina” were often used interchangeably, and Schlichting was about to challenge both stamina-based theories (which were rooted in an adapted vision of seeds) and broader atomic ones.18 Like the atomists, his first and cardinal postulate was that nothing in nature is divisible ad infinitum, and, as a consequence, some basic matter must exist.19 Yet, rather than stopping at atoms or particles, he went on to make the radical case that something more fundamental must spawn even the most basic seeds of things: a liquid. Another of his later and most elementary postulates—“Ex nihilo nihil fit” [“Out of nothing, nothing is created”]—likewise has an Epicurean and indeed Aristotelian thrust, but is ostensibly in conflict with the Protestant doctrine of creation ex nihilo (Schlichting 1742c, f. 3r). Schlichting, however, appears to have supposed that his liquid matter better suited the Biblical creation account than the solid particles of the atomists.20 While he did not dwell on this point, he reckoned that God molded the natural world out of a liquid that he either spoke into existence on the first day of the six-day creation or that had eternally existed, a position that was easily squared with the claim in Genesis 1:2 that the “Spirit of God moved upon the face of the waters” even prior to a creative act.
Despite the scriptural evidence for a primordial liquid, neither of the above positions were standard within Biblical criticism. With that being said, the renowned English classicist, theologian, FRS, and Master of Trinity College, Cambridge, Richard Bentley, did propose in one of his Boyle Lectures, published as The Folly and Unreasonableness of Atheism in 1699, “that a solid inanimate Body, while it remains in that state, where there is none, or a very small and inconsiderable change of Texture, is wholly incapable of a vital production. So that the first Humane Body, without Parents and without Creator, if such an one ever was, must have naturally been produced in and constituted by a Fluid” (Bentley 1699, pp. 106–7). Bentley went on to conclude, however, that this was impossible for one of two reasons: either complex bodies were originally formed as “Heterogeneous parts were jumbled and confounded together by a Storm, or Hurricane, or Earthquake,” which he rejected out of hand, or they came into existence owing to a “Hydrostatical Law.” He dismissed the latter because, according to this law, a body that is heavier than a fluid sinks to the bottom, while one that is lighter than a fluid floats to the top, and, since this did not seem to hold in the case of humans, for whom dense bones are wrapped in light flesh, Bentley jumped to the conclusion that Adam and Eve must have been originally formed by God and not nature. While Schlichting by no means advocated the atheistic position that the first humans emerged without a divine command, he sought to display throughout “Sapientiæ Problema” that such summary rejections of an original fluid did not take into account the intricate ways in which liquids turned into solids, and vice versa, every day.
On the most foundational level, Schlichting spurned a simplistic dichotomy between primordial chaos and lawful nature, and rather contended that chaos (by which he meant the primitive, formless quintessence that chymists also dubbed “prima materia”) had been ordered by a vital animating power all along. According to his account, what was normally styled prima materia was therefore not actually the first and most basic matter but instead a mixture of Aristotelian and chymical fundamentals, including earth, water, salt-acid, alkaline, oil, and air, which he supposed to be, in their own right, configurations of a vital liquid and animated by it.21 He maintained that semina, in turn, are produced out of materia prima, whence other bodies of the same kind are typically generated.22 As he formulated his notion of generation, Schlichting accordingly conjured the following material hierarchy:
Liquid Matter → Materia Prima → Semina → Bodies
Schlichting may have found inspiration in the localized insights of medically-trained near contemporaries such as van Helmont and Stahl, but it was to the wider annals of philosophy that he turned to shore up his guiding principle that everything comes from and resolves into a liquid. Most significantly, he plucked Lady Philosophy’s assertion in Boethius’s Consolation of Philosophy that “It is decreed by eternal law that nothing that is generated can remain firm” [“Constat æterna positumque lege est, / Ut constet gentium nihil”] (Schlichting 1742c, f. 10v and Boethius 2008, II.3.18). Early modern natural philosophers who turned to the history of philosophy to develop their matter theories mainly called upon one of two perspectives: natural bodies either resolved into a single type of matter, a position that was often traced back to so-called pre-Socratics such as Thales, or they resolved into multiple types, which was most commonly associated with the four-element theories of Empedocles and later Aristotle. Whereas van Helmont assimilated the former, Boerhaave famously propounded an adapted form of the latter in his 1732 chymistry textbook, Elementa chemiae, when he argued that “bodies generated from the earth and water, when at last they decay and die, return again into air, water or earth” (Boerhaave 1741, p. 137). Extending the chymical critique of four-element theories but refusing to follow van Helmont in stopping at water, Schlichting strove to establish, once and for all, the singularity of a more fundamental, non-solid matter.
With his liquid, Schlichting not only challenged atomic and four-element theories but also, more remarkably, the notions of stamina that were à la mode across Europe. Rooted in the concept of eternal seeds first introduced by the fifth-century BC philosopher Anaxagoras of Clazomenae, “stamina” came to signify everything from the “native or original elements and constitution of anything” to “congenital vital capacities,” and, as noted in the introduction, they were usually visualized as fibrous bundles that contain a plant or animal in outline (OED, “stamina, n.,” 1a and 2a).26 Reinvigorating the idea for an early modern audience, the French atomist Pierre Gassendi summoned stamina (which he nonetheless supposed to be composed of smaller atoms) to make the case for preformation in the section of his 1658 Opera Omina on the generation of plants. By Schlichting’s day, however, stamina were more commonly associated with the microscopic observations of Malpighi, according to whom they were the most minute beginnings of living bodies.27 On this basis, it was widely assumed, even among those who did not wholeheartedly embrace Malpighi’s findings, that such a principle, as opposed to unorganized matter of either a mechanical or vital variety, accounted for the emergence of living beings. Garden, for one, explicitly linked Malpighi’s stamina with preformation in his 1686 “A Discourse Concerning the Modern Theory of Generation.”28 Invoking Malpighi’s 1673 Dissertation epistolica de formation pulli in ovo, Garden directly pitted preformationist theories dependent on stamina against epigenetic ones that relied on fluids when he explained that the “sudden appearance and displaying of all the parts after Incubation makes it probable, that they [embryos] are not then actually formed out of a Fluid, but that the Stamina of them have been formerly there existent, and are now expanded” (Garden 1686, p. 475).
While Malpighi was not in fact a straightforward proponent of preformation at all, Garden unsurprisingly juxtaposed his defense of stamina against William Harvey’s account of epigenesis.29 Quite famously, Harvey had posited primordial blood as the material cause of animal generation, and his foremost eighteenth-century epigenetic heir, Caspar Friedrich Wolff, transfigured blood into a vaguely defined “liquid.” As Wolff explained, “the thing which is, in the beginning, excreted from or produced by the maternal ovary is none other than the drop of liquid located in the egg in which there is no structure similar to the structure of the parent” (Wolff 1973, p. 149). But, despite his recourse to a general liquid, Wolff confined himself to discussions of animal generation, whereas Schlichting’s conviction that a strong degree of continuity existed between animal, plant, and metal formation spurred him to pursue a unified generative theory.
Even if blood was only of localized significance for Schlichting, he nevertheless followed Harvey in holding that it was a tremendously protean substance that could morph into anything from hard fibers when it coagulated (as he supposed polyps exemplified), versatile vessels that further facilitate the circulation of blood, and thin membranes that line the tissue.30 His stress on the primordial vitality of blood is especially striking within the mid-eighteenth-century Dutch context, where the influence of René Descartes guaranteed that blood was most frequently characterized as passive (French 1989). There were, however, a number of powerful voices that Schlichting could summon to support his view, including that of the esteemed seventeenth-century Dutch botanist and anatomist Frederik Ruysch, who observed that when a vein is bled a thin skin rapidly covers the surface, which is no less perfect than the original membrane.31 On Schlichting’s reading, Ruysch offered solid proof of the adaptability of blood, and, more generally, the fact that there was nothing more common in nature than the transformation of a liquid into a solid. While his broader emphasis on all things coming from and returning to liquid was rather idiosyncratic, Schlichting was in good company with his specific notion that blood easily solidifies, which was shared not only by Ruysch but also the eminent Professor of Medicine at Leiden, Hieronymus David Gaubius (Verwaal 2017, p. 277).
Notwithstanding his affinities with Harvey and Wolff, it is important to clarify that Schlichting was by no means a champion of epigenesis. Indeed, he took at face value Leeuwenhoek’s microscopic observation of a miniature tree folded in a seed, with the contours of a trunk and leaves fastened to its side, though he was sure to note that the prolonged figure within the seed intimated a liquid origin.32 Further suggesting that Schlichting had consulted the archives of the Transactions, he probably had in mind Leeuwenhoek’s argument from a 1693 paper “concerning the Seeds of Plants” that each seed contains “not only the Rudiments of the future Plant” but also a flower “of an oily Nature” that nourishes the embryonic plant (Leeuwenhoek 1692, p. 701). Whereas Leeuwenhoek and many of his contemporaries held that fluids nourish yet do not create solids, a prominent York physician and FRS Clifton Wintringham went further the year after Schlichting sent “Sapientiæ Problema” to the Royal Society, averring that it is not liquid that will “increase the Bulk of the Animal” but “new Particles by adhering firmly to the original Stamina.” As he reasoned, if an internal fluid incited growth one might be tempted to conclude that “the Animal would have a Power of making its own Fibres and Vessels, and consequently of producing itself” (Wintringham 1743, pp. 8–9). Schlichting’s position, then, was precisely the one that Wintringham feared: namely, that the oil of the seed and the future plant have the very same material origin and that, if one looked more broadly at material transformations, even preformation theories could be squared with a liquid universe.
It should now be clear that Schlichting’s target was not preformation (which he subtly promoted) but the adjacent idea of pre-existence according to which, in the words of Garden, “the Stamina of all the Plants and Animals that have been, or ever shall be in the World, have been formed ab Origine Mundi by the Almighty Creator within the first of each respective kind” (Garden 1686, pp. 476–7). When Schlichting postulated that all procreation or generation is a real creation [“Procreatio seu generatio mihi est vera creatio”], then, he was not promoting epigenesis so much as crafting an attack on the notion, plainly stated by Garden, that all natural bodies have existed eternally in stamina.33 While Schlichting acknowledged the world to be approximately 5,000 years old, the injuries that solid bodies were bound to incur through erosion and constant clashes led him to take it as an axiom that no body could exist for more than the generous estimate of 1,000 years, not even stamina.34 On his reckoning, only an amorphous liquid could last the test of time.
Seeking to experimentally moor his axioms, Schlichting invoked the research of the great Italian Aristotelian and Professor of Logic at the University of Pisa, Domenico Benivieni, on the “fungus adiposus” (a tumor that Schlichting’s other article in the Transactions investigated).35 When Benivieni had extricated some of these tumors, he discovered that they did not merely grow in bulk, but were composed of minuscule cells that multiplied from a clump of coagulated blood, which Schlichting compared to the proliferation of fibers and solidification of a tree in outline within a once-liquid seed.36 Whereas advocates of indestructible stamina took recourse in the notion that God had created a multitude of seeds for each species to safeguard the perpetuity of natural kinds, Schlichting still had to clarify how a liquid matter, which was devoid of rationality, could preserve species distinctions through the mere tumor-like proliferation of fibers. To this end, he contended that species persist in mostly perfect states because living specimens imbibe the fundamental liquid and convert it into the requisite material to continue their kind. In making this case, he again called on Malpighi, according to whom the original of an animal (which he termed semen) is a liquid that is digested, mixes with the blood, suffuses the vessels, and moves into the testes. This seminal liquid adheres to female semen in the uterus to form the fibers and vessels that make up embryos.37 In addition to affirming Malpighi’s point that liquids give rise to solids, Schlichting maintained—perhaps inspired by Boerhaave’s claim in his 1724 Institutiones et experimenta chemiae that animal digestion converts vegetable chyle into blood—that one liquid could turn into another, which ultimately allowed him to posit a single underlying liquid (see Orland 2012, p. 360).
Schlichting rounded off the opening section of “Sapientiæ Problema” with two further postulates, the first of which was that a substance that nourishes a body must be of the same nature as that body, which was almost certainly based on the chymical notion that like yearns after like (see Pagel 1982, pp. 10–11). Since a liquid (namely, water) was generally understood to nourish a seed, he concluded that the seed itself must be essentially liquid.38 A related postulate was that all beings capable of growth require a circulating liquid, which he extended to seeds themselves. While this position was of course based on the discovery of the circulation of the blood that was widely thought to mirror the motion of sap, Schlichting’s contention that the same was true for seeds hinged on a microscope-induced appreciation for the sophistication of these minuscule bodies.39 Indeed, he went so far as to label the liquid that circulates in seeds “humorum,” harking back to Galenic humoral theory.40 Schlichting’s choice of terminology is especially notable given that humors were almost always considered in relation to humankind, and, even when plant and animal “humors” were mentioned, it was usually in the context of how consuming vegetables and flesh affected human humoral dispositions.41 One is hard-pressed to find the association of seeds with humors even among the most ardent proponents of material pre-existence. But, since Schlichting diverged from supporters of stamina-based theories in seeing seeds not as starting points but as manifestations of an advanced generative stage, he was far happier to impute complex liquid functions to these tiny bodies.
Botanically-literate individuals such as the English virtuoso Thomas Browne had contended in the previous century that “seeds contain much oyle within them,” while John Ray informed Royal Society associates that “the Seed, at least in most plants, did conteine besides the young plant, a convenient portion of Nourishment” that was liquid (Browne 1658, p. 170 and Ray 1674, f. 291). But, as Ray indicated, it was usually taken for granted that fluids had either always existed within seeds or that they seeped in, little by little, for the sake of nourishment. These juices were then transformed, on Boerhaave’s account, into the “new and peculiarly vegetable juice proper to each part of the plant” (Boerhaave 1741, p. 140). Schlichting’s notion that liquid formed stamina before nourishing them was, however, virtually unheard of, especially when coupled with his idea that seeds, being akin to miniature plants or animals with circulating humors, must increase in bulk even before they burst and expand into full-fledged beings.
Hisao Ishizuka has argued that the early eighteenth-century stress on stamina and fibers “bears witness to a concerted effort of medical theorists to transform the older medical theory of the ‘humoral’ and fluid body into a theory of solidism” (Ishizuka 2012, p. 563).42 Such a view certainly holds to a large extent in the British context, where various prominent Newtonian physiologists opposed the notion of vital liquids entirely, and instead emphasized the propulsion of fluids around a mechanically-constructed body.43 Thomas Morgan, for one, wrote in 1735 “that the Solids are indued with Elasticity, as a constant uniform Spring or Power of Motion; whereas the Fluids have no such Property or active Force at all” (Morgan 1735, p. 145). With his hypothesis that all solid matter had liquid roots, however, Schlichting sought to liquefy not only the avant-garde concepts of “fibers,” “vessels,” “membranes,” and “stamina” that were widely applied to living beings, but the entire natural world. While this put him at odds with Cartesians and British Newtonian physicians (among others), he was convinced that such a theory was necessary to solve the major problems facing stamina-based accounts of generation.
4. Geological Transformations and Spontaneous Generation
Following the “postulata,” “Sapientiæ Problema” begins to move up the scale of nature, starting with the generation of metals and advancing to that of plants and animals. Self-conscious about this structure, Schlichting even scribbled in the margin at one point “transitus ab herbis ad animalia” [“transition from herbs to animals”] to ensure that readers grasped his organizational rationale (Schlichting 1742c, f. 23r). Like the preponderance of mid-eighteenth-century physicians and natural philosophers, Schlichting was convinced that a large degree of continuity existed between life forms, but his emphasis on a vital liquid prompted him to go further than most in refusing to distinguish categorically between spontaneous and sexual generation, and thus the emergence of plants or animals from that of tumors, metals, or mountains.44
Before he climbed the scala naturae, Schlichting’s first challenge was to establish that liquid matter could spawn non-living bodies. According to the time-tested view, which was based on a “cyclical theory of the earth,” mountains appear and disappear due to evaporation and flooding, or, to use the words of Nathanael Carpenter, “the Continent and firme land is turned into the Sea, and other-where the Sea hath resigned places to the Land” (Carpenter 1625, Bk. II, p. 196). Such a position was expounded in ancient sources from Plato’s Timaeus and Aristotle’s Meteorologica to Ovid’s Metamorphoses, and persisted during the seventeenth and eighteenth centuries, most famously with Robert Hooke and John Woodward.45 But whereas Schlichting’s precursors tended to discuss the changing landscape in terms of slow transformative processes with certain fixed fundamentals (such as mountains that were engulfed by oceans which gradually dried up), his conviction that all natural bodies are the products of constant material creation led him to argue that liquid matter from the ocean formed mountains. As he explained, a vital liquid that permeates the sea is chaotically tossed around and mixed with material from the seabed, and, as the body of water dries up, this material is slowly squeezed and hardened by the atmosphere, at which point mountains are formed.46 Given the young age that Schlichting accepted for the Earth, he evidently conceived of this liquid as an extremely strong workman, but, from his perspective, a formless liquid was far better suited to a vision of thoroughgoing geological change than a world chock-full of solid and everlasting atoms or stamina.
Schlichting’s claim that an energetic liquid spawned mountains would have been contentious in its own right, but this was only a detour en route to addressing what he deemed to be a more pressing question: how are metals formed? His answer related to the formation of other non-animate bodies and especially shells and fossils. Relevant here is a heated late seventeenth-century controversy that erupted in England between Ray and Hooke, on the one hand, who held that fossils were the shells or bones of creatures, and Robert Plot and Martin Lister, on the other, who argued that they could spontaneously generate (Roos 2011a). Perhaps counterintuitively, the first position was the more subversive one, since it had long been recognized, based on the authority of Genesis and Aristotle, that God created each and every species at the beginning of time, and many of these fossils lacked known, corresponding creatures. While Schlichting unmistakably sided with Plot and Lister, they had both considered the material cause of fossils and shells to be generative seeds scattered in the ocean, whereas he sought to simplify the issue by arguing that they were formed (similar to mountains) as a vital liquid intermixed with mud. Unlike shells, however, metals did not wash up on the shore but had rather long been mined from mountains, a fact that the radical preacher and chymist John Webster popularized in his 1671 Metallographia Or, an History of Metals.47 Schlichting therefore had to find a related yet different explanation for their generation. On the assumption that bodies as dense as metals could not take shape within a chaotic ocean, despite it being rich in vital liquid, he ultimately ventured that they required a peaceful “uterus,” and were thus generated as the liquid that was lodged within inchoate mountains gradually solidified.48
While Schlichting’s account of metal formation was distinctive, his general suggestion that metals originated from a liquid was not. On the contrary, as Ana Maria Alfonso-Goldfarb and Marcia H. M. Ferraz have shown, there was a widespread early modern belief, which the Bohemian minister Johannes Mathesius had introduced, that metals were formed out of a buttermilk-looking sulfur-mercurial fluid that God had implanted in the Earth, and which often went by the German word guhr. According to authorities from van Helmont to Boerhaave, this liquid slid through the entrails of the Earth, and, as it rose towards the surface, it hardened and eventually transformed into dense metals (Alfonso-Goldfarb and Ferraz 2011). Although Schlichting’s agreement with this view was a natural outstretch of his wider theory, it is also likely that he was taking a specific jab at Stahl who rejected the assumption, which united chymists and Aristotelians, that metals were generated at all, and rather insisted that God originally created them in more or less their current state (Stahl 1766, p. 255).49
Schlichting pivoted from the generation of metals to that of plants and animals by calling upon the relatively standard idea that only the last two could reproduce their own kind.50 He proceeded to offer a handful of examples to illustrate the infinitely powerful reproductive capacities of vegetables [“ut exemplo fertilem fruticum propagationem juxta et infinitam multiplicationem experirer”] (Schlichting 1742c, f. 9r). Underscoring the “fractal” character of trees, Schlichting compared their bursting and unfolding out of seeds to how branches, which could become full-blown trees in their own right when severed and planted, protrude from a trunk.51 This example would have probably been of interest to Royal Society affiliates, with Abraham Trembley’s conclusion that the fresh-water polyp (or hydra) was able to generate “as perfect an Insect, as that of which it was originally only a Part” after “being cut into Several Pieces” having made a splash around the same time (Trembley 1743, p. 1; also see Dawson 1987). Schlichting also relayed more remarkable experiments including the horizontal submersion of a willow in water, which nonetheless survived by shooting an abundance of roots into the ground and branches upwards, and the uprooting and inversion of a mature tree, which prompted its roots to transform, by degrees, into branches and its branches into roots (Schlichting 1742c, ff. 14v–16v). But whereas Trembley’s principal aim was to assess the animal/plant distinction, Schlichting’s goal in emphasizing the generative potential of each seed, branch, and bud was to cast doubt on the idea that the stamina that gave rise to every plant—never mind animal, mineral, and metal—could have existed for all of time.52 On the basis of the infinite reproductive power of vegetables alone, he concluded that if stamina were eternal then the world must have originally resembled an infinite heap of seeds, leaving no matter to facilitate their growth and nourish full-fledged beings. For Schlichting, it seemed far more likely that liquid formed and nurtured seeds that, in turn, occasioned the succession of their kind, leaving plenty of matter to feed the diverse life forms that populated the natural world.
In an attempt to stave off such a critique, a number of Schlichting’s contemporaries had tried to calculate the exact size of infinitesimal stamina. Wintringham, for example, reckoned that “all the Stamina, from which so noble a Being as Man himself was at first derived, could not contain so much solid Matter as would be equal in Bulk, to that of a Quantity of Water, of no greater a Weight than the 1/92408129934910602442073752000th part of a Grain” (Wintringham 1743, pp. 18–19). Quantitative analyses of stamina, more generally, usually revolved around computing the size and weight of their fibers so as to mathematically demonstrate that there was sufficient space on the Earth to house the untold number required to produce each being from the beginning until the end of time. But Schlichting argued that positing such minute stamina merely postponed the problem, for one still had to explain how bodies that were so diminutive as to make the smallest seeds appear colossal could engender large plants or animals in such short stints. As the Catholic priest and FRS John Turberville Needham went on to point out in 1749, those who defended this view had not “consider’d the immense Disproportion, between the great Expansion of this Web and the inconceivable Minuteness of the Animalcule; otherwise it had appeared as rational to suppose, that an Alpine Mountain could have been rear’d in a few Days by a single Emmet successively pileing one Grain of Sand upon another” (Needham 1749, p. 6). While Schlichting’s conjecture that mountains formed in the ocean over hundreds or thousands of years might have seemed farfetched to some, Needham made it appear far more believable than the idea that a child might unfold in all of its complexity from an invisible “animalcule” or “stamen” in just nine months.
Even if Schlichting held that most animals are the products of copulation, his emphasis on the generative power of liquid matter meant that he was happy to embrace spontaneous generation not only in the case of mountains and metals but also animals. Edward Ruestow has contended that, by the late seventeenth century, naturalists “repudiated spontaneous generation in any form,” and it is true that there was pushback against this idea, which had flourished in centuries prior (Ruestow 1984, p. 227; also see Mendelsohn 1976 and Farley 1977). Most notably, Francesco Redi combated spontaneous generation in his Esperienze intorno alla generazione degl’ insetti (1687), in which he sought to establish, on observational grounds, that maggots do not spring from putrefied flesh but are rather the progeny of flies that incubate their larvae in fecal matter (see Parke 2014). For his part, Swammerdam had castigated spontaneous generation in the 1670s as an atheistic thesis propagated by heathen philosophers, likely with the controversial Epicurean proposition that the fortuitous motions of semina formed the earliest humans in mind (Swammerdam 1737–8, vol. 1, p. 171; vol. 2, pp. 394, 432, 669, 708–13).53 The theory that God created innumerable stamina—as a Christian adaptation of the more rhetorically charged Epicurean notion of semina—was developed in part to forestall this verdict: insects may emerge from the stamina around rotting flesh, but putrefaction is not the material cause of their generation.
While many figures rejected spontaneous generation, plenty of others did not. Thomas Henshaw surmised in a 1682 epistle to Robert Southwell, for instance, that each animal has “a peculiar vermin apperteining to it,” and, with a theological twist, he continued that “Divine Providence may for very good reasons have appointed in certain cases a power of generation to ye concurrence of certain Agents and patients as well as to that of Males and femelles, nor is ye previous Matter in equivocall productions more unlike than that in other generations,” with particular reference to worms and lice (Henshaw 1682, f. 2v). Moving into the eighteenth century, the august Italian Jesuit Filippo Buonanni similarly defended spontaneous generation, at least when it came to animals without blood or a heart, with the broadly Aristotelian explanation that the heat of the sun can animate inert matter (see Gottdenker 1979, pp. 580–1).54 Like Henshaw (and indeed Ruysch), Schlichting took it for granted that worms could form out of blood, and he further noted that lice pestered humans no matter how assiduously they washed their person or clothes (Schlichting 1742c, f. 29r).55 More strikingly, he also entertained the idea, which he derived from the renowned Dutch Renaissance physician Levinus Lemnius’s 1559 Occulta naturae miracula, that even mice might generate spontaneously in hot and dry seasons, though he admitted that the efficient cause of this remained a mystery.56
The increased recognition of the sophistication of small creatures—whether worms, lice, or mice—was easily seen as further evidence against spontaneous generation, prompting Ray to fear a slippery slope that might precipitate apologies for the spontaneous emergence of primal humans (Ray 1693, p. 16). But Schlichting was unperturbed by such dilemmas, and simply deemed his vital liquid, which had Biblical justification and allowed him to develop rigorous explanations for fiber and vessel multiplication, to better account for spontaneous generation than the theories of Epicurus, Aristotle, or indeed his near contemporaries. In his refusal to strictly distinguish the generation of the parts of a life form from the whole, it seemed only reasonable to Schlichting that organisms proliferated in much that same way as the cells that comprised tumors.
While the young Leeuwenhoek would have agreed with Schlichting that the multiplication of animalcula in water or putrefied flesh could spawn complex beings, even he had become an adamant opponent of spontaneous generation by the late 1680s.57 Leeuwenhoek’s change of heart was the outcome of both experiments, one of which involved placing raw meat in glass tubes to bask in the sun and perceiving that no signs of life appeared, and microscopic observations, which drove him to conclude (like Swammerdam) that putrefaction could not possibly produce such intricate beings. As a proponent of the view that all bodies have the same essential and simple source, however, Schlichting saw no reason to assume that the argument from complexity applied any less to the formation of flies in putrefied meat than the emergence of children from stamina or oaks from once liquid seeds.
5. Royal Society Revisions
In order to address the final question of why “Sapientiæ Problema” was never published, we must turn to Baker’s detailed notes, which sit next to the treatise itself in L&P/1. While the exact purpose of his abridgment remains unclear, the fact that Baker commences it with the formal declaration that “The Manuscript I am going to give the Substance of, is intitled by its Author Sapientiæ Problema, a Problem of Wisdom, concerning the Generation of Seeds” implies that his summary was for more than personal use. On this score, it may also be significant that both Baker’s précis and Schlichting’s manuscript are included in the L&P collection, which consists of official Letters and Papers of the Royal Society. While there are no extant minutes for Society meetings between 22 December 1742 and 14 June 1743, it is highly likely that Baker’s notes, rather than the manuscript itself, were read before this institution. Indeed, meetings had long been conducted principally in English to accommodate the many gentlemen fellows, and Schlichting’s other contribution to the Transactions, though published in Latin, was tellingly translated into English to be read before the Society and later printed in English in a widely circulated standalone volume of the Transactions (Schlichting 1742b, 1809). If “Sapientiæ Problema” was read at a Society meeting—as is almost certainly the case—it would have been one of the most theoretical pieces on natural bodies and their generation to have been presented in years, perhaps even since Kenelm Digby’s famed 1660 Discourse Concerning the Vegetation of Plants. As has been suggested, the Royal Society of Schlichting’s day had generally come to favor concise, observationally-driven papers that cited moderns rather than ancients where possible and spurned grand physical theories (Sorrenson 1996).
Attempting to shoehorn Schlichting’s paper into the preferred format, Baker’s notes give a selective but detailed content breakdown of the manuscript. Whereas Baker recorded all of the “postulata” besides the last, he was less consistent when it came to Schlichting’s conclusions. Not only did he strip the later sections of virtually all references back to the postulates, but he also left out points that he found unnecessary, repetitive, or unconvincing while diligently reordering examples that he thought illustrated previous points. In the process, he accurately captured the tenor of Schlichting’s treatise, though his selections (and omissions) do occasionally bear the imprint of his natural philosophical predilections. He bypassed, for instance, all of Schlichting’s appeals to medieval or ancient authors, whether Aristotle, Seneca, or Boethius, but diligently jotted down his citations of modern ones like Ruysch and Malpighi. It is notable here that Baker’s publications in the Transactions from the 1740s—on topics from “The Grubbs Destroying the Grass in Norfolk” to “Concaves of Ancient Roman Coins Found in Shropshire”—exhibit his intense interest in natural history and archeology as well as his fondness for an observation-led approach that did not leave much room for the history of philosophy or totalizing natural theories (Baker 1746a, 1746b). In this regard, it is also significant that Schlichting’s final postulate, which is the only one that Baker overlooked, consists of the broadly Aristotelian claim that all effects have a knowable cause, but that philosophers, anatomists, and chymists of his day, with their spirits, virtues, and qualities, were ignorant of the relevant material energies [“energiæ materiæ”].58 A rather chary Baker would undoubtedly have considered this emphasis on the indispensability of causation and foregrounding of material energy, not to mention the pessimism about natural philosophical progress, to be a step too far, and certainly a concatenation of views that he preferred not to ventilate before the Royal Society.
Since Baker was engaged as much in a process of translation as selection, his word choices also provide an intriguing glimpse into the vernacularization of natural philosophical and medical ideas around the mid-eighteenth-century Royal Society. Specifically, in striving to convey Schlichting’s principles, Baker deployed a decidedly Latinate set of English terms, many of which were lexicographical newcomers. This includes the late seventeenth-century verb “extravasate,” which combined the Latin “extra” (outside) with “vās” (vessel), and which signified in English “to flow out or to force its way out” (sometimes but not always with reference to a vessel) (OED, “extravasate,” v. 2). Another example is “grume” from the Latin “grūmus” meaning “little heap,” which came to denote a “viscous fluid or mass of fluid” in early eighteenth-century English, usually with reference to blood (OED, “grume,” n. 2). In tension with the notion of a movement from liquids to solids in eighteenth-century English natural philosophy, it is striking that both of these Latin terms were liquified as they were Anglicized.
Baker also retained Latin vocabulary where no adequate English equivalents existed or when terms had been already incorporated into the lexicon. One example is “congeries,” a rather obscure term that natural philosophers such as Robert Boyle and Ralph Cudworth had, during the previous century, transposed directly from the Latin to denote “a collection of things merely massed or heaped together” (OED, “congeries,” n.). Less remarkably, Baker followed Schlichting’s usage of “liquamen” for “liquid matter” and “materia prima” for prime matter, evidently regarding these technical terms as untranslatable. Especially with the gradual breakdown of the Aristotelian concept of substantial forms, natural philosophers had to be highly inventive and selective in how they adapted and deployed Latin terminology to capture the nature (or lack thereof) of bodies and substances.
In one sense, Baker was an appropriate reader for Schlichting’s manuscript, not least because many of his findings were grounded in microscopic observations and his best-selling 1743 The Microscope Made Easy was in preparation when “Sapientiæ Problema” was received. He also published a few relevant papers in the Transactions during the early 1740s, including one on “The Discovery of a Perfect Plant in Semine,” which argued for preformation without appealing to stamina and posited a strong degree of continuity between plant and animal formation despite rejecting spontaneous generation (Baker 1740). While Baker did not allow his ideas to interfere meaningfully with his summary of “Sapientiæ Problema,” he obviously had philosophical predilections, and these may well have discouraged him from recommending its publication. No letter accompanies Baker’s notes, and, precisely because of his aversion to methodological ruminations, it is difficult to extract a statement of intent from his output. But a manuscript letter that he dispatched to his friend and fellow naturalist John Browning over a decade later on 10 July 1758 regarding John Hill’s 1757 The Sleep of Plants tellingly advised Browning to be “content with the Honour of discovering a real Fact, without perplexing yourself with Steams or vibrating Fibres.” Upon hearing of Browning’s failure to replicate Hill’s experimental results, according to which sunlight triggered certain plants to open their leaves, Baker proudly announced that
What we collect from the Information of our Senses may be called Knowledge, what from Matters our senses cannot examine, however we may flatter [^ourselves] is merely the Work of Fancy, which presents a more or less ingenious Fancy or Romance according to the strength of the Inventive Faculties and this wants no Proof so long as the Epicurean, the Cartesian, and many other Systems of Philosophy shall be remembered. For my own Part, Nullius in Verba is the Motto of the Royal Society. (Baker 1758, f. 4r)
The fact that “Sapientiæ Problema” never appeared in print and that Schlichting did not send another paper to the Royal Society is the ultimate indication that his reception was not the one that he had anticipated. Without a journal that would showcase more theoretical pieces and lacking the will or assurance to expand his treatise into a monograph, he had no choice but to shelve it.
Schlichting’s “Sapientiæ Problema” represents the final death throes of universal material explanations for natural generation and change. While his treatise would have been perfectly acceptable, and maybe even celebrated, in the seventeenth century, his willingness to extrapolate from selective experimental data made it less so by the mid-eighteenth. The fact that his ideas on a generative liquid never saw the light of day is, however, highly unfortunate, not only because they offered a powerful critique of material pre-existence, but also because we can now only catch a glimpse of how such an all-encompassing physical theory would have been immediately received. In spite of the dearth of evidence for the reception of “Sapientiæ Problema,” its rediscovery complicates several dominant assumptions about the period of its composition. For one, Schlichting’s treatise raises questions about whether the eighteenth-century proclivity to strip chymical concepts of all “excesses” and gear them towards useful ends was as ubiquitous as sometimes supposed, since engagement with the “arte chemica” was central to his case for a single liquid as the fundamental material of the universe, with no discernibly practical payoff.
Schlichting’s treatise should also prompt a reconsideration of extant interpretations of mid- to late eighteenth-century “vitalism.” As is now relatively well known, medically-trained thinkers from Stahl at the University of Halle to Théophile de Bordeu and Paul-Joseph Barthez at the University of Montpellier began to chalk up a bright-line between the vitality of living, organized beings and the inert, mechanical matter composing the natural world at large.59 While at least some of them sought to counter Descartes’ “body machine,” these physicians mostly slipped into a generalized albeit material dualism that treated the natural world as purely mechanistic even if some beings possessed a non-mechanical spark of life. It was this inexplicable livelihood that was thought to warrant a divorce between the study of organic life and the rest of nature, and fed into the replacement of atoms or seeds that constituted any part of nature with stamina that existed eternally with the blueprint of a specific living being.60 Yet we have seen that this idea of stamina was the very one that Schlichting strove to demolish. As a counterblast to the almost exclusive application of vitalist theories to animate bodies—with various mid-eighteenth-century thinkers attempting to replace the active, fluid spirits of Galen or the blood of Harvey with solid nerves or elastic fibers—Schlichting’s universal generative liquid more closely resembled the matter theories wrought by figures such as Margaret Cavendish and Francis Glisson a century prior than those of his near contemporaries.61
While this article has explored many of the sources for “Sapientiæ Problema” and the polemical backdrop against which Schlichting’s liquid matter theory was formulated, it is finally worth situating him in relation to one significant but hitherto unmentioned development in continental natural philosophy. Moving into the eighteenth century, the natural philosopher probably most willing to posit a universal matter theory was Leibniz. The text in which he most fully expounded his perspective was his posthumously published 1720 Lehrsätze über die Monadologie, which was translated into Latin as Principia philosophiae and printed in the Acta Eruditorum the subsequent year. As a short manuscript treatise that proceeds through postulates and conclusions, this text shares several stylistic features with Schlichting’s. Indeed, along with valuing Leibniz’s emphasis on causation and natural teleology, it is striking that Schlichting also followed him in using localized observations to derive principles that applied across life forms. Complicating simplistic distinctions between experimental/speculative or empiricist/rationalist approaches to the natural world, one way to view Schlichting’s treatise is accordingly as an heir to the work of Leibniz, whose grand pronouncements about matter and causality were inspired to an appreciable extent by the careful microscopic observations of Leeuwenhoek, Malpighi, and Swammerdam (see Becchi, 2016; O’Hara 2016). But the conclusions that Schlichting drew from many of the same sources were diametrically opposed to Leibniz’s. In particular, Leibniz’s famed concept of the monad—as a lively, inherently organized particle that contains all of the parts needed to form an organic body—can be seen as a merger of stamina/animalcula theories with the generalized particulate ones so prominent a century earlier. Schlichting, by contrast, returned to the theories of illustrious seventeenth-century physicians and naturalists in an effort to undermine particulate and stamina theories alike, and to establish a universal liquid substance that could overturn the virtual consensus about natural pre-existence.
For this conception of the stamina, see Ishizuka 2012, pp. 577–9.
On Locke’s epistemic modesty apropos substance and its reception, the classic source is Yolton 1983, pp. 14–28.
For his lineage, see the title page of Schlichting 1730.
On Verbrugge, see Zuidervaart 2019, p. 91.
The thesis reads: “Seminum generatio quod hodie adhuc fiat, uti antehac, ita et in posterum, eaque quod sit infinita” (Schlichting 1742c, f. 5r).
“Non est divisio particularum minimarum in infinitum” (Schlichting 1742c, f. 1r).
“In quod aliquid resolvitur, ex eo constat et vice versa” (Schlichting 1742c, f. 1r).
“Chaos sive materies prima, seu non disposi-ta dicatur, (quod non possidet formas, quæ
est inde producentur) est nil nisi liquida variæ materici miscela, composita ex terra, aqua, sale acido, alcali, oleo, aere, etc.” (Schlichting 1742c, f. 4v).
“Per Vim alque motum corporis per-fecti ex materia prima semen aut genitale primordium, unde simile corpus perfectum porro germinat, progignitur” (Schlichting 1742c, f. 4v).
“Omne animal, et quæ ex terra progignitur herba, resolvuntur, arte chemica in mate-riam liquidam sive liquamen” (Schlichting 1742c, f. 1r).
“Per motum varium ætheris, aeris, aquæ, concursu materiæ heterogeniæ, atque demum sequente quiete, complures produci formas, physices atque chemia periti haud ignorant” (Schlichting 1742c, f. 4v) and “Sin universum corpus animatum et vegitatum verò constat liquamine, nunc rite in formam certam disposito, ejus igitur Semen ex eodem constare, negavi non potest” (Schlichting 1742c, f. 2r).
On Anaxagoras, see Lewis 2011.
For a broader discussion of Garden and generation, see Guerrini 2002.
“cruor igitur fluidus commotus fibris veris non constat, alias vasa adeo parva iste transfluere haud posset, sed quiete reteutus, coagulatus, in fibras vergit, in membranas, in vasa” (Schlichting 1742c, ff. 24v–25r).
“Ast conquassatus quod proferat membranam fibris conflatum, adeo pulcram, ubi exarescit, acsi effet natura progenita, ut expertus summus inventor Ruischius scripsi” (Schlichting 1742c, f. 25r).
“Semen prættæ arboris faxini inves-tigans Leeuwenhoekius microscopüs armatus, vidit solum parvam futuræ arboris miniat-uram, quæ futuræ arboris truncum constituat, radicibus ac ramis orbatam, cui appingit folia, quæ latitudine eum superant, long-itudine fere æquant” (Schlichting 1742c, f. 19r).
“Omne seminis genus perfectam possidere formam aut figuram, quoad omnes partes convenientem illi, quod pullulatur inde, atque tantum magnitudine hinc discrepare, nemo aut αυτοψεíα, aut argumentis ullis vel minimum ad verum accedentibus stabiliuit” (Schlichting 1742c, f. 3v).
“Nullum ejusmodi corporum per mille annos perseverat, neque tam diu tot injuriis variorum motuum in mundo obviorum resistere pollet. Quocirca semen eorum (i.e. Stamen genitale) quod adhuc tenerius est, mille aut bis mille annos et ultra persistere nequit […], si in mundi principio omnia semina essent create, quum jam ultra quinque millia a mundo condito annorum recensemus” (Schlichting 1742c, f. 2v).
“fungus adiposus, qui interdum pondus 60 librarum æquat, aut minus, ut refert Benivenius, me duce cultro amputatus, et factis experimentis, scissione, coitone, assatione, ite exquisitus, inventus est acervus cellularum servo impletarum” (Schlichting 1742c, ff. 20v–21r).
“posito enim Stamine rei viventis ejusue principio germinante, in quo congeries est tantum paucarum fibra-rum minimarum similum, crescentium, excrescant facile reliquæ partes totum complentes, necesse est. Idem enim hic et fieri potest et debit, quod de ramusculo, nodo ac semine stirpium declararimus” (Schlichting 1742c, ff. 27r–28v).
“Collatis his, ajo, atque perpensis, judicare me oportuit, animalis primordium primum, quod Semen vocamus, liquidam esse ma-teriem, in corpus vivum cum alimento ingestam, digestam, inter cruorem abviam, per omnia vasa pulsam, posthac in testibus separatam, paratam, dispositam, ut, si in utero una cum eo, quod de formina deredit, commista, in quietem redigatur cruoris, gelatinæ aut muci instar” (Schlichting 1742c, f. 27r).
“Materia seminis, ejusdemque nutrimenti, eadem sit oportet” (Schlichting 1742c, f. 4v).
On the circulation of sap, see Roos 2011b, pp. 151–66.
“Semen Vivum quodcumque Si formam habet, ac tamdiu absque vitæ interita aut structuræ destructione perstat, et motu igitur et humorum circuitu vel minimo gaudeat ac nutrimento indigeat, opus est. quoniam nulla res figurata inter regnum herborum et animantium absque humo-rum circulo servari nequit. Sin autem hoc ita est, semen igitur absque sui augmento atque æque parvum servari tot annis haud potest” (Schlichting 1742c, ff. 4v–5r).
For an overview of humoral theories, see Nutton 1993.
Also see the argument that fibers become the main building blocks of natural life in Cheung 2010.
“Semotis igitur præjudiciis ac collatis invicem, quæ experien-tia comprobat, ac quæ majoribus hac de re litteris mandata sunt, eò commotus sum, ut crediderim, montes omnes et altissimos olim, sicuti adhuc, oequoris motu, concussione, allisione, e materia prima (chaos dicta postul. XIV) in mari quæ perpetua est, congestos, et gravitate materiæ suæ propria, atque sempiterna ambientis aeris pressione, compactos et formatos, ita denique comparuisse” (Schlichting 1742c, ff. 5r–6v).
For a fuller discussion of this work, see Clericuzio 1996.
“In montibus igitur ipsis metallorum genesis quærenda est, quæ figuratos atque in uterum versos ac dispositos montes sequatur [et…] materia prima liquida congelata ac in metalla conversa fuisse” (Schlichting 1742c, f. 8v).
On the generation of metals from “moist exhalations” in Aristotle, see Eichholz 1949.
“Quare et herbarum ac fruticum semina, aut genitalia primor-dia, inde, eademque modo, iisdemque, aut similibus saltim causis adhuc produci, manifestum est, facta solum ea diffe-rentia, quod herba herbam producat, quod de metallo adhuc dici nequit” (Schlichting 1742c, f. 9r).
“liquida materie, post formatas, unde prodeunt, arbores, ast haud aliter, quam fibris a stirpitibus usque porrectis, elongatis, explanatis, in forma minima, congestis quibus vis se porro multiplicandi inest” (Schlichting 1742c, f. 17r).
“Si vera sunt, quod denegari haud potest, atque si juxta statuimus ad vulgi hypothesin, cuncta semina, coepto mun-do, creata, actu et quoad formam extitisse, ac temporis succesu alterum ex altero, evolvi, sequatur, oportet, omnem materiem et formatam et rudem (informem) ac quicquid existit, semen – esse aut seminum congeriem, puta herbam, animal, metallum, chaos, terram, aquam, sal, oleum, spiritum, aerem, ætherem; immo sic totum nostrum orbem nil nisi seminum figuratoram acervum habendum” (Schlichting 1742c, f. 12v).
On the atheistic implications of spontaneous generation, see Goodrum 2002.
For Ruysch on the formation of worms out of blood, see Knoeff 2008.
“Neque dicam, de progenie pulium musearum infectorum, vermium, etc., corumque mirabili metamorphosi, quæ cuncta, Levino Lemnio teste, ex materie liquida, absque Seminibus ante existentibus, subinde prodeunt, cum vero causa effec-trix latescrit, et ignari nasute Supersti-tiosa futilia ac vana præcepta religiose observant, jurantes in verba Magistri, omnes æque coeci” (Schlichting 1742c, f. 29r). On Lemnius, see Crowther 2008.
On the multiplication of animalcula, see, for example, Leeuwenhoek 1696, p. 166.
“Philosophi olum ut nunc, mechanismi ac energiæ materiæ inscitia, anatomes ac chemiæ imperiti, spiritus, virtutes, quali-tates finxere, omnium effectuum præcipuas causas” (Schlichting 1742c, f. 5r).
On these earlier generalized seed theories, see Hirai 2005.
The research for this article was generously supported by the Lisa Jardine Award of the Royal Society. I am grateful to the librarians at the Royal Society, especially Virginia Mills, for their assistance with the collections. Many thanks also to Ruben Verwaal, who carefully read an earlier draft of this article and was a huge help in navigating the Dutch material, as well as to Fabrizio Bigotti and an anonymous referee for their insightful comments.