STAHL, GEORG ERNST

(b. Ansbach, Germany, 20 October 1659; d. Berlin, 14 May 1734), chemistry, animism, vitalism, combustion, alchemy, medicine. For original article on Stahl see DSB, vol. 12.

Stahl has a prominent place in the histories of both chemistry and medicine, and had a successful career in court service and medical practice. His attempt to account for the inflammability of matter and reduction of metals was developed in the eighteenth century by his followers into a phlogistic paradigm preceding the modern chemistry of combustion that Antoine-Laurent Lavoisier (1743–1794) and his colleagues established. His medicine stressed the fundamental difference between the organism and the machine, and was thus opposed to a medical orientation of his time that sought to reduce medicine into mere mechanics and hydraulics of body parts and fluids.

Much new work has been done or come to light since the publication of Lester S. King’s biography of Stahl in the original DSB. Stahl’s year of birth, long held by historians as 1660, was found to be 1659 based on a birth certificate found in his parents’ parish church in Ansbach. His formulation of life has been under rigorous analysis by philosophers and historians alike. There have been fine studies on his relationship with the Pietsts in Weimar and Halle. And very importantly, scholars have come to a better understanding of Stahl’s chemistry, matter theory, and alchemy, subjects that King neglected to a large degree in his biography.

Career and Life Stahl was born into a Lutheran family in Ansbach, Germany in 1659. His father Johann Lorenz, an MA, worked in different times as a secretary to the council of the court (Hofrat) of Brandenburg-Ansbach, the Lutheran church consistory, and the local marriage court; his mother Maria Sophia Meelführer was the daughter of a local deacon. He went to the local gymnasium and thereafter studied medicine at Jena, then a stronghold of chemical medicine. Stahl received his MD at Jena in 1684, and taught there as an unsalaried lecturer until he began in 1687 to serve as personal physician (Leibmedicus) to the Duke of Saxon-Weimar. In 1694 he accepted the offer of the professorship of medicine at the newly opened University of Halle. He and Friedrich Hoffmann (1660–1742), also a Jena MD and an advocate of mecha

nistic medicine, soon made their faculty one of the most flourishing in Germany, although they before long developed an intense rivalry. Also on the faculty upon the inauguration of Halle were Christian Thomasius (1655–1728), famous jurist representative of the Early Enlightenment in Germany; August Hermann Francke (1663– 1727), theologian and leader of German Pietism; and Johann Franz Buddeus (1667–1729), professor of moral philosopher and Lutheran theologian. Christian Wolff (1679–1754) joined the faculty later, in 1706.

Although he thrived as a professor of medicine, Stahl also enjoyed a distinguished career as a clinician and a courtier. He practiced medicine from the time that he received his MD, if not earlier, and renewed his courtier career when he was called in 1715 to serve as first physician to King Friedrich Wilhelm I of Prussia (r. 1713–1740). Compared with Hoffmann’s dismissal from the same position in 1712 after a mere three years, Stahl’s continual service at court in Berlin until his death was a significant success, and doubtless it was owed to the king’s trust in his medical care. His fame as a clinician transcended national borders so that the ailing Russian Tsar Peter the Great tried twice to invite him to his sickbed in St. Petersburg. Besides attending to the health of the king and his family, Stahl was a court councilor (Hofrat) and was entrusted with the presidency of the medical board that regulated issues related to medicine, pharmacy, and public health in Berlin and later over all of Prussia. He was also instrumental in the founding of a college of medicine and surgery (inferior to the university in status) in Berlin in 1724.

Scientific Work in Chemistry Stahl’s chemical work demonstrates the width and depth of his knowledge of chemical practitioners’ work, as well as of his own empirical observations and experimentations. His first book, Zymotehnia Fundamentalis (1697), showed his acquaintance with brewers’ and bakers’ practical knowledge of fermentation. His works on metallurgy, inflammable materials, and salts recorded his familiarity with miners’ and smelters’ practice and beliefs and with chemical literature, in addition to his rich observations on minerals and often elaborate laboratory experiments.

Stahl had a corpuscularian, and largely mechanistic, interpretation of matter and chemical processes. Though agnostic about the number of the most fundamental particles, which he at times identified as indivisible atoms, he postulated that natural substances resulted from the aggregation or compounding (mixtio) of composite corpuscles of different orders. Chemical processes were the recombinations of the constituent corpuscles of starting materials. Because the primary qualities of the fundamental particles were unknown, Stahl proposed to examine the changes of physical and chemical qualities at the phenomenal level. He nevertheless was certain that particles were by nature passive, and their motion was transported by other particles in motion and ultimately came from heat. His rather mechanistic interpretation of fermentation, basically as the release of sulphurous particles in the fermentable materials, quietly rejected the theories of fermentation prevalent prior to his time that stressed the ferment as a somewhat magic agent that accounted for material changes in all the three kingdoms of animal, vegetable, and mineral. It also left no room for the Aristotelian form in the explanation of material constitution and changes.

Stahl himself did not seem to see phlogiston as his invention. Following Johann Joachim Becher (1635– 1682), he denoted the substance underlying all inflammable matters with the term phlogiston, although the roots of this notion can be traced at least back to the Paracelsian notion of sulphur as the principle of inflammability. This trace is evident in Stahl’s regular references to inflammable or oily substances as sulphurs and his frequent substitution of “phlogiston” with Schwefelswesen (essence of sulphur or sulphurous being). What distinguished his Schwefelswesen from the previous Paracelsian principle of sulphur was its material identity. The Paracelsian principle worked like the Aristotelian element to the extent that it showed no material consistency in the different substances of which it was said to form a part. Robert Boyle especially ridiculed this material inconsistency of the Paracelsian principle and Aristotelian element in his Sceptical Chymist. As Boyle’s criticism was absorbed by the following generations, Stahl postulated, and tried to demonstrate, that the material composition of phlogiston remained uniform in all bodies that contained it, even though it did not exist in nature as a pure uncompounded substance. Phlogiston could be released into the air from inflamed sulphurous minerals, from vegetable substances in fermentation, or from animal parts in putrefaction. It could come into the corporeal constitution of animals by their digestion of vegetables, or into the vegetable constitution by the absorption of the air. Thus phlogiston circulated across the three kingdoms of nature and around the globe in air streams. It was nutrition for plants, especially for resinous trees. It reduced calxes into their metallic forms, restoring their luster, tinkling sound, and fusibility; when losing their phlogiston, metals were reversed into calxes. Thus phlogiston played a key part in the reduction of metals.

Conception of Vital Principle Stahl’s conception of material constitution dictated his theory of life. He observed that organic bodies decomposed almost immediately when deprived of life, and reasoned that the strong corruptibility of organic matter resulted from its chemical nature. He thus postulated that there must be a reason or a vital principle that kept the living body from its natural decomposition, and that this reason of life could only derive from something other than matter. Meanwhile the delicacy and complexity of life seemed to require that this vital principle worked with alacrity, precision, and spontaneity in response to the organism’s real-time needs to maintain health and ward off threats. Thus Stahl assumed that this principle must be an immaterial agent, which he sometimes called natura (nature), and sometimes anima(the soul). Galen and his early modern followers in medicine also taught that each organ had its natural “reason” so that it knew to perform its natural faculty at the right time, in the right way, and under the right circumstance. For Stahl, this spiritual agent, anima, usually exercised natural reason (ratio) in the conservation of the body or its parts, rather than performed the logical reasoning (ratio-cinatio) of the rational soul (often identified as animus by Stahl and his contemporaries). Because anima guided and regulated physiological processes in the living body, once misled, by emotions, for example, it produced illnesses. In this sense it became a pathological agent. The participation of anima in physiology and pathology in accordance with reason and the purpose of life thus made the living organism distinct from a machine made of dead material parts. Medicine, the science of life, therefore must never be a mere application of mechanical principles.

Such a formulation of life ascribed much to the healing power of nature, a doctrine that dates back at least to the Hippocratic authors. For Stahl, the fact that very often the organism healed itself without resorting to medicine served as a proof of natura or anima at work, employing natural measures such as fever, hemorrhages, vomiting and diarrhea when necessary. The aim of the physician’s therapeutics was to facilitate this natural healing power based on attentive observation. Reckless interventions or crude applications of mechanical principles would cause disastrous effects.

It must not be thought that Stahl ignored the importance of mechanism in medicine. The material body was an indispensable instrument of the soul, and its operation basically followed mechanical principles. He assigned a great place to what he called tonic motion (motus tonicus), a contractive and relaxative movement of body parts or tissues. In his theoretical formulation that took almost a decade to complete, the contraction and relaxation of the tissues regulated the passage of the circulatory blood, and, thanks to the porous structure of the tissues, filtered out waste and harmful particles in the capillary blood flow into excretive ducts, thus playing as a key devise of metabolism. All these functions of tonic motion were achieved through corporeal mechanisms, although, as always, anima as the agent directed the motion.

Critique of Alchemy Stahl was an interested investigator of alchemy in the first few decades of his career but later turned into a critic. He examined as a believer the theories and experiments on the philosopher’s stone in the first chemistry course he taught in 1684, and still wrote approvingly, though also cautiously, on transmutation in the 1700s. In works published in the late 1710s and 1720s, he came to criticize Becher’s alchemical belief and the general Renaissance alchemical assumptions, although he retained his allegiance to Becher’s theory of material composition. In his well-known “Bedancken von der Gold-macherey,” he distinguished between chemistry (chemie) and alchemy (alchemie), seeing the former as useful, practical work as opposed to the latter as fruitless, and often fraudulent, effort.

A deeper significance of Stahl’s criticism is his departure from the vitalist cosmography that the alchemy of Becher and many Renaissance authors relied on. Renaissance vitalism often assumed an animating principle that originated in the heavens and permeated the celestial and terrestrial space alike, or a vital principle that was immanent to the most fundamental unit of matter, the monad or semina. In contrast, Stahl’s formulation of life and matter deprived organic substance of any form in the Aristotelian sense, of the animal and vital spirits in Galenic medicine, and of the cosmic spirits or immanent seminal principles. This formulation broke with the unity of heaven and earth, and of life and matter in Renaissance vitalism, and came to emphasize the difference between the living organism and dead matter, and indeed between the bio-medical and the physico-chemical.

It is often suggested that Stahl’s medicine had a natural bond with Pietism. It is true that Stahl had a long relationship with the Pietists, which began at least at the court of Saxon-Weimar, ran through his tenure at Halle, and continued even at court in Berlin. He was on good terms with Francke and served a king who, though Calvinist himself, was a patron of the Pietists. Some of Stahl’s students either played important parts in the pharmacy of the Weisenhaus (as Fracncke’s institution of charities was known) or became devout Pietists. Yet these relations were not enough to confirm that Stahl’s sympathy with Pietism shaped his medicine or that Pietism was by nature opposed to mechanistic medicine. Stahl’s rival, the mechanist Hoffmann, for example, befriended and was befriended by the Halle Pietists, and also supported some programs of the Weisenhaus. Robert Boyle, probably the best-known mechanical philosopher, was held in high regard by the Pietists. Although Stahl shared with the Pietists’ criticism of excessive mechanistic reductionism, it must be remembered that Boyle and Hoffmann, as good Christians, were careful to avoid the danger of atheist materialism. By contrast, Stahl’s physiology, pathology, and therapeutics showed few elements that were distinctly characteristic of Pietism (spiritual rebirth, for example), or that proposed religious causation of illnesses (such as the effects of sin on health).

Influence The influence of Stahl’s medical and chemical teachings was enormous over Europe throughout the eighteenth century. His students Johann Juncker (1679– 1759) and Michael Alberti (1682–1757) carried on his chemical and medical teachings at Halle. Alberti especially incorporated Pietist ideas into his medicine. Stahl’s emphasis on the irreducibility of biomedical phenomena to mechanical laws inspired the doctrines of the so-called Montpellier vitalists, including François Boissier de la Croix de Sauvages, Théophile de Bordeu (1722–1776), and Paul-Joseph Barthez (1734–1806), although the eighteenth-century vitalists, finding it increasingly difficult to defend the place of anima in medicine for theoretical and empirical reasons, later differentiated themselves, “the vitalists,” from Stahl, “the animist.” Although Albrecht von Haller, perhaps the most influential medical figure in mid-century Germany, was critical of Stahl, eminent late eighteenth-century figures in life sciences such as Johann Friedrich Blumenbach (1752–1840) and Pierre Jean Georges Cabanis (1757–1808) hailed him as a genius in medicine. Stahl’s chemistry was introduced to Paris largely thanks to Guillaume François Rouelle (1703–1770), and found among his followers Pierre-Joseph Macquer (1718– 1784) and Gabriel-François Venel (1723–1775). His teaching of phlogiston was developed in the 1780s and 1790s into a theory of combustion that tried to incorporate new findings in pneumatic chemistry by Joseph Black (1728–1799), Joseph Priestley (1733–1804), Henry Cavendish (1731–1810), Carl Wilhelm Scheele (1742– 1786), and others. Stahl’s formulation of tonic motion is discernible in the discussion of tonic motion in the lectures of John Thomson (1756–1846) published as late as 1813.

SUPPLEMENTARY BIBLIOGRAPHY

Stahl published most of his works in Latin, the academic language of his age, prior to 1715, the year of his departure for Berlin. Then gradually his works were translated into German, and in the 1720s especially, his dissertations were translated in large numbers. Stahl supervised more than a hundred and forty dissertations, and wrote a great majority of them on his students’ behalf. In Halle he experimented with new forms of publication of his age: for example, a personal periodical, Observationes physico-chymico-medicae curiosae (monthly from July 1697 to June 1698, apparently imitating his colleague Thomasius’ well-known precedence Monatsgespräche ), and a learned journal, Observationvm selectarvm ad rem litterariam spectantivm (1700–1705), co-edited with Thomasius and Buddeus. In Berlin he began to write and publish directly in German, which met with the new trend of learned German chemico-medical authors’ publication practice.

WORKS BY STAHL

Dissertatio epistolica ad Tit. Dominum Johannem Adrianum Slevogt … De motu tonico vitali, & hinc inde pendente motu sanguinis particulari. Jenae, Germany: Sumtibus Joh. Jacob Ehrten, 1692. The first of Stahl’s publications on tonic motion.

Zymotechnia fundamentalis, seu Fermentationis theoria generalis … Halle, Germany: Typis & sumptibus Christoph. Salfeldii, 1697. A theory of fermentation, where Stahl’s matter theory was first laid out.

Propempticon inaugurale de differentia rationis et ratiocinationis… Halle, Germany: 1701. A dissertation program on the difference between natural reason (ratio) and logical, reflective thinking (ratiocinatio).

Dissertatio medica inauguralis de vita. Halae Magdeburgicae: Typis Johannis Jacobi Krebsii, 1701. One of Stahl’s first treatises that formulated what life was.”

Specimen Beccherianum …” In Physica Subterranea by Johann Joachim Becher. Lipsiae: Apud Joh. Ludov. Gleditschium, 1703. Stahl republished Becher’s work in order to append this commentary.

Opusculum chymico-physico-medicum curiosorum. Halae Magdeburgicae: Typis & Impensis Orphanotrophei, 1715. A collection of Stahl’s early works, including Zymotechnia Fundamentalis and articles published in his personal periodical and in the journal Observationvm selectarvm.

G. E. Stahls zufällige Gedancken und nützliche Bedencken über den Streit von dem so genannten Svlphvre … Halle, Germany: In Verlegung des Wäysenhauses, 1718. Stahl’s study on inflammable bodies and their material base.

Georgii Ernesti Stahlii Negotium otiosum, seu, Skiamachia: adversus positiones aliquas fundamentales, theoriae verae medicae à viro quodam celeberrimo intentata… Halae: Litteris et Impensis Orphanotrophei, 1720. A collection of the polemic epistolary exchanges between Stahl and Leibniz on the nature of life.

Herrn George Ernst Stahls, … Chymia rationalis et experimentalis: oder, gründliche, der Natur und Vernunfft gemässe und mit Experimenten erwiesene Einleitung zur Chymie … Leipzig, Germany: bey Caspar Jacob Eysseln, 1720. A chemical textbook based on the notes of his lectures given in 1684. It was translated into English by Peter Shaw as Philosophical Principles of Universal Chemistry … (London: Printed for J. Osborn and T. Longman, 1730), which is one of the very few works by Stahl available in English.

Ausführliche Betrachtung und zulänglicher Beweiss von den Saltzen … Halle, Germany: In Verlegung des Wäysenhauses, 1723. A treatise on salts.

Billig Bedencken, Erinnerung und Erläuterung uber D. J. Bechers Natur-Kündigung der Metallen. Frankfurt & Leipzig, Germany: W. C. Multz, 1723. A commentary of Becher’s Natur-Kündigung der Metallen (1661), in which Stahl criticized alchemical theories and beliefs on the nature of metals.

Ausfürliche Abhandlung von den Zufällen und Kranckheiten des Frauenzimmers. Leipzig, Germany: C. J. Eysseln, 1724. A collection of Stahl’s gynecological dissertations, translated into German.

“Gedancken von der Gold-Macherey.” In Johann Joachim Becher, Chymischer Glücks-Hafen, oder, Grosse Chymische Concordantz und Collection … Halle, Germany: Verlegts Ernst Gottlieb Krug, 1726. Stahl’s relatively well-known critique of alchemy.

Praxis Stahliana, das ist … Collegium practicum … Leipzig, Germany: Eyssel, 1728. A collection of Stahl’s medical cases.

OTHER SOURCES

Chang, Ku-ming (Kevin). “Fermentation, Phlogiston, and Matter Theory: Chemistry and Natural Philosophy in Georg Ernst Stahl’s Zymotechnia Fundamentalis.” Early Science and Medicine 7 (2002): 31–64. An analysis of Stahl’s largely mechanistic matter theory that places his formulation of fermentation in the intellectual context of his age and his own conceptual development.

———. “The Matter of Life: Georg Ernst Stahl and the Reconceptualizations of Matter, Body, and Life in Early Modern Europe.” PhD diss., University of Chicago, 2002.

———. “Motus Tonicus: Georg Ernst Stahl’s Formulation of Tonic Motion and Early Modern Medical Thought.” Bulletin of the History of Medicine 78 (2004): 767–803. An analysis of the formulation and development of Stahl’s theory of tonic motion.

———. “Georg Ernst Stahl’s Alchemical Publications: Anachronism, Reading Market, and a Scientific Lineage Redefined.” In New Narratives in Eighteenth-CenturyChemistry: Contributions from the First Francis Bacon Workshop 21-23 April 2005, 23-43. Dordrecht: Springer, 2007.

———. “From Vitalistic Cosmos to Materialistic World: The Lineage of Johann Joachim Becher and Georg Ernst Stahl and the Shift of Early Modern Chymical Cosmology” In Chymists and Chymistry: Studies in the History of Alchemy and Early Modern Chemistry, edited by Lawrence M. Principe, 215-225. Segamore Beach, MA: Science History Publications, 2007.

Coleby, L. J. M. “Studies in the Chemical Work of Stahl.” PhD diss., University College, University of London, 1938. A very good study of Stahl’s chemistry, unfortunately never published, and thus very rare.

De Ceglia, Francesco Paolo. Introduzione alla fisiologia di Georg Ernst Stahl. Lecce: Pensa, 2000. A survey of Stahl’s physiology.

———. “The Blood, the Worm, the Moon, the Witch: Epilepsy in Georg Ernst Stahl’s Pathological Architecture.” Perspectives on Science 12 (2004): 1–28. A study of Stahl’s conception of epilepsy and pathology in general.

Duchesneau, François. “G. E. Stahl: Antimécanisme et Physiologie.” Archives internationale d’histoire des sciences 26 (1976): 3–26. Duchesneau, a philosopher and an intellectual historian, analyzes Stahl’s medical thought with philosophical rigor.

———. “Leibniz et Stahl: divergences sur le concept d’organisme.” Studia Leibnitiana 27 (1995): 185–212.

———. “Stahl, Leibniz, and the Territories of Soul and Body.” In Psyche and Soma: Physicians and Metaphysicians on the Mind-Body Problem from Antiquity to Enlightenment, edited by John P. Wright and Paul Potter. Oxford: Clarendon Press, 2000.

Engelhardt, Dietrich von, and Alfred Gierer, eds. Georg Ernst Stahl (1659–1734) in wissenschaftshistorischer Sicht: Leopoldina-Meeting am 29. und 30. Oktober 1998 in Halle (S.). Halle (Saale): Deutsche Akademie der Naturforscher Leopoldina, 2000. The proceedings of a conference on Stahl.

Geyer-Kordesch, Johanna. “Georg Ernst Stahl’s Radical Pietist Medicine and its Influence on the German Enlightenment.” In The Medical Enlightenment of the Eighteenth Century, edited by Andrew Cunningham and Roger French. Cambridge, U.K.: Cambridge University Press, 1990. A very influential article that suggests Stahl’s strong ties to the Pietists.

———. Pietismus, Medizin und Aufklärung in Preussen im 18. Jahrhundert: das Leben und Werk Georg Ernst Stahls. Tübingen: Niemeyer, 2000. A fundamental work that elucidates the Pietist background for Stahl’s life and work. Includes an updated, though selective, bibliography, of works by and on Stahl, limited to his medical works.

Goetze, Johann Christoph. Scripta D. Georg. Ern. Stahlii …, aliorumque ad ejus mentem disserentium, serie chronologica … Norimbergae: Apud Petr. Conr. Monath, 1726. A contemporary, annotated bibliography of Stahl’s publications, albeit not complete.

Helm, Jürgen. “Das Medizinkonzept Georg Ernst Stahls und seine Rezeption im Halleschen Pietismus und in der Zeit der Romantik.” Berichte zur Wissenschaftsgeschichte 23 (2000): 167–190. A study of the reception of Stahl’s influence in Halle Pietism and German Romanticism.

———. “‘Quod naturae ipsae sint morborum medicatrices.’ Der Hippokratismus Georg Ernst Stahls.” Medizinhistorisches Journal 35 (2000): 251–262.

———. Krankheit, Bekehrung und Reform: Medizin und Krankenfürsorge im Halleschen Pietismus. Habilitationschrift, Universität Halle-Wittenberg, 2004. A section of this fine work reconsiders the place of Pietism in Stahl’s medicine work.

Hoffmann, Paul. “La controverse entre Leibniz et Stahl sur la nature de l’âme.” Studies on Voltaire and the Eighteenth Century 199 (1981), 237-49.

———. “L’âme et les passions dans la philosophie medicale de Georg-Ernst Stahl.” Dix-Huitiènme Siècle 23 (1991): 31–43.

Metzger, Hélène. “La Philosophie de la matière chez Stahl et ses disciples.” Isis 8 (1926): 427–464.

———. “La théorie de la composition des sels et la théorie de la combustion.” Isis 9 (1927): 294–325. These two outstanding articles form the basis of the part on Stahl in her Newton, Stahl, Boerhaave et la doctrine chimique (Paris: Alcan, 1930).

Partington, J. R., and Douglas McKie. “Historical Studies on the Phlogiston Theory.” Annals of Science 2 (1937): 361–404; 3 (1938): 1–58, 337–371. A series of papers that traces the development and fall of the phlogiston theory in the works of the late eighteenth-century pneumatic chemists.

Rather, Lelland J. “G. E. Stahl’s Psychological Physiology.” Bulletin of the History of Medicine 35 (1961), 37–49.

Rather, Lelland J., and John B. Frerichs. “The Leibniz-Stahl Controversy—I: Leibniz’ Opening Objections to the Theoria Medica Vera.” & “The Leibniz-Stahl Controversy—II: Stahl’s Survey of the Principal Points of Doubts.” Clio Medica 3 (1968): 21–40; 5 (1970): 53–67. An English translation of part of the polemics between Stahl and Leibniz, with a concise analysis.

Strube, Irene. Georg Ernst Stahl. Leipzig, Germany: B. G. Teubner, 1984. A book that is based on her dissertation, “Der Beitrag Georg Ernst Stahls, 1659–1734: zur Entwicklung der Chemie,” University of Leipzig, 1961. It is in her dissertation that Stahl’s birth certificate was first presented, and it corrected the received knowledge of the year of his birth.

Völker, Arina, and Wolfram Kaiser, eds. Georg Ernst Stahl (1659–1734): Hallesches Symposium 1984. Halle (Saale): Martin-Luther-Universität Halle-Wittenberg, 1985. The proceedings of a conference held in the 250th anniversary of Stahl’s death.

Völker, Arina. “Bei Durchsicht der Stahlschen Disputatioslisten.” In Georg Ernst Stahl, edited by Arina Völker and Wolfram Kaiser. Halle (Saale): Martin-Luther-Universität Halle-Wittenberg, 1985. A list of Stahl’s dissertations. It does not include the prefaces (called programs or propempticons) he wrote for a selected number of the dissertations. These dissertations and programs are very important for understanding Stahl’s medical teaching.

Ku-Ming (Kevin) Chang