Vortrag am Descartes Center for the History and Philosophy of the Sciences and Humanities, Utrecht University, Utrecht, 23. März 2010
When studying different psychosomatic concepts in the history of medicine, we generally notice a certain duality of aspect in psychosomatic processes. On the one band there are ideas, images, pictures, and illusions upon his own body or infect other bodies by communication, producing a physiological disorder or a psychological epidemic. This may be called the power of Imagination (Vorstellungs- or Einbildungskraft), On the other band, combined with Imagination, there are natural powers, which were called „(nervous) fluid“ (fluidum) in the early and „psychic energy“ (psychische Energie) in the late nineteenth century correlating one part of the human body with another, one individual organism with another, or a human being with the whole of nature—linking microcosm (man) and macrocosm (world). The most essential idea of natural philosophy, from the Stoics to the Romantics, claims that all bodies, including the human organism, are connected to each other by net-works of magnetic influence. This may be called the power of magnetism. This concept includes the concept of sympathetic interaction: the transference of vital powers within the body or from one body to another.
This concept of Imagination or fantasy is central to the history of medicine, especially since the Renaissance. It derives from antiquity and was widely discussed by Greek philosophers, especially Aristotle. It was traditionally used to differentiateimagination from the effects of demons, as can be still observed in the learned literature of the early modern period. Imagination or fantasy was of great importance to philosophical discourse in the Renaissance, especially in the work of Ficino. His model of „fascinatio,“ exemplified in De amore by the rays sent through the eyes bringing about love sickness as well as the evil eye (böser Blick) was fundamental to later discussions of imagination as a process of natural magic. The universities and courts of the Renaissance expressed a general ambivalence regarding magic, depending on the assumed moral Status of the person who practiced it. The issue of „white“ versus „black“ magic became an important topic of learned discussion. In his work on natural magic, Giambattista Della Porta (1535-1615) included a special chapter on the question of how to become possessed by „fascination“ and how to protect oneself from it.
The concept of imagination implies potential proximity to the traditional idea of demonic possession. A pathogenic imago, like a demon or parasite, is incorporated into the mind by a sort of injection. It may develop dynamic powers within the mind and body of the „possessed“ person, but it can also be transferred to other individuals or even to natural things in general. The idea of magnetism derives from the cosmological concept of interaction. Occult powers within the natural world influence the human organism. Magic medicine is used to cure sick persons by so-called magnetic techniques. They are believed to strengthen the vital powers of the organism—in other words, to accumulate vitality. But there are also destructive powers of magnetism. They weaken vitality and take away life energy—like vampires. The long tradition of magical practices and sympathetic cures documents the importance of magnetic influence as a medical idea. It is remarkable that the fundamental idea of magnetism as a vector for imagination (imaginatio or phantasia) has been largely ignored by historians of medicine. What has been published tends to take a philosophical or psychological perspective on imagination, neglecting the physical or substantial counterpart, which was stressed by Paracelsus and van Helmont, the most important thinkers on magic and (al)chemical medicine in the early modern period.
natural magic: paracelsus on imagination
This essay will show that the Paracelsian concept of imagination is closely related to the concept of magnetism. Imagination and magnetism are linked in the work of Paracelsus (= Theophrastus von Hohenheim [1493/4-1541]), to whom „The whole of heaven is nothing other than imaginatio influencing man, producing plagues, colds, and other diseases.“ The same is true for the microcosm, the individual human organism, for which Paracelsus uses the metaphor of an inner sun: „Well, what else is imaginatio than a sun within man, havin
g such an effect in his globum [body], that is, thereon it shines?“ Indeed, there are, according to Walter Pagel, „concordances in detail between the lore of the Cabalah and the teaching of Paracelsus.“
What, then, is the basic model of imagination and magnetism for Paracelsus? First, the attractive power of the magnet symbolizes the power of imagination; Paracelsus characterizes both powers this way: „As the magnet can attract steel, there is also a magnet in the imagination, which also attracts. There is an imaginatio like a magnet, and an impressio like the sun and heaven, making a man by the power vulcani.„ Paracelsus provides an example (Exempel), a parable, to explain the identity of imagination and magnetism. The magnet is a metaphor for the imagination: „Without hands and feet, the magnet attracts iron. Like the magnet attracting the visible, the corpora (bodies) are invisibly drawn to the imagination by itself. But it is not the corpus (body) that enters, but what the eyes see and is not palpable, i.e., form and color.“ The attraction (incorporation) of an object (ding) by the imagination (a quasi magnet) is followed by an impression of this introjected object, like the impression the sun and heavens put on a man. „What climbs up into heaven is imaginatio, and what falls down is impressio born out of the imagination.“ This movement describes a reflex action, tying together microcosm and macrocosm. A macrocosmic reflex occurs, for instance, when the (evil) imagination of a human individual poisons the stars, which send the poison back to the earth, causing plagues and disorders.
In his treatise De causis morborum invisibilium (On the invisible diseases), Paracelsus uses the term imaginatio (imagination) to explain the correlation between body and soul. „The imagination is a master by itself and has the art and all Instruments and all it wants to produce, for example as a cellarman, painter, metalworker, weaver, etc…. What does imagination need? Nothing more than a globe on which it can work, that is, the screen on which it paints what it wants to paint.“ In this way, the imagination of a pregnant woman can impress itself directly on the body of the child in the womb: „The woman with her imagination is the workmaster and the child is the screen on which the work is perfected. The hand of the imagination is invisible, the Instrument also, and both work together…. So the imagination does its work at that place, in the way the imagination has decided it.“
In this context, Paracelsus defines the power of Imagination as „belief“ (Glaube). Belief is „like a workman’s instrument“ which can be used for good as well as for evil purposes. Belief can produce any disease. Paracelsus compares it to a weapon. Disease will be produced when the weapon is active against its originator. Paracelsus uses the parable of the man with a gun, which can be compared to the reversion of affections (Affektverkehrung) in modern psychology: „We produce our diseases, so we become similar to a man who has got all his weapons and guns. But when he meets a manikin aiming at him with a ready gun the big man is anxious about the weapon and is frightened by it—the same happens to us…. When we become weak, the power of our belief hits us as a shot from a gun, and we have to tolerate and to suffer what we have thrown against us.“
Paracelsus calls self-destructive belief „despair“ (Verzweiflung). It is the reversal of our belief which makes us weak and sick. The gun is directed against our-selves. The pathological imagination may even give rise to an epidemic, such as the plague. The most important cause of the plague, therefore, is that people in despair may „poison heaven, so some will suffer from plague, depending on their belief.“ Imagination represents great danger if it is combined with despair and returns to its own origin. As pointed out above, this mechanism constitutes a sort of reflex action.
It is worth noting that Paracelsus links his theory of imagination and magnetism to social and political phenomena, explaining events of mass psychology, such as the attraction that a leader exerts on a crowd of people. In this context, Paracelsus again uses the magnet as a metaphor: „You find a man who knows to speak, so that all the world runs to him and listens. Know, then, that his mouth (Maul) is a magnet, powerfully attracting the people.“‚
In his treatise Philosophia magna Paracelsus discusses the effect of the „right belief“ (rechter Glaube), which could promote a strengthening and healing imagination. This concept was stressed by Paracelsians such as Oswald Croll: „The belief produces an imagination, whereas the imagination produces the stars (by marriage with the imagination)…. To add belief to the remedies gives the spirit or mind to the medicine: But the mind is the knowledge of medicine: The medicine or remedy is sanity: Therefore it is consequent, that the medic or physician originates from the belief….“ Croll’s annotation recommends Paracelsus’s On the invisible diseasesas appropriate reading.
magnetism and world soul: gilbert, kepler, and the consequences
In the late sixteenth and early seventeenth centuries, after Paracelsus, magnetism became a central topic of natural philosophy, experimental science, and medical theory. The influence of the prominent authors Gilbert, Kepler, and Kircher on science and medicine until the eighteenth century can hardly be overestimated.
William Gilbert (1544-1603) published bis studies on magnetic phenomena under the title De magnete, magnetisque corporibtts, et de magno magnete tellure in 1600, the same year he became court physician to Elizabeth I. He was the first to distinguish „electrics“ from „magnetics,“ that is, the attraction caused by the amber effect from that caused by a lodestone. Rubbed amber or substances that behaved in a similar way (electrics) emitted effluvia to pull small particles inward. Magnetic materials like the lodestone (magnetics) shared their ability of attraction with the earth as a giant lodestone. Gilbert called the spherically ground lodestone a terella, since it did not depend on the emission of effluvia for attraction. Every magnet was surrounded by an invisible orb of virtue. Magnetics within this orb would be attracted to the magnetic body. But the specific difference from other sources of attracktions was “magnetic coition”m the mutual action of the attracting and the attracted body, the „coming together of two bodies harmoniously.“ Magnetism turned out to be the world soul, and the magnetic force appeared to be a psychic force: it „is animate or imitates a soul; in many respects it surpasses the human soul, while that is united to an organic body.“ This idea corresponds to the principle of natural magic (magia naturalis) and the concept of magnetism in medicine, especially in regard to the so-called rnagnetic-sympathetic cures in the early modern period. But Gilbert did not emphasize the idea of „imagination“ or „fantasy“. His physical approach to magnetism was quite different from the Paracelsian conception.
Johannes Kepler (1571-1630) worked as a mathematician at the court of the German emperor Rudolf II in Prague from 1599. The intensive discussion at the court of alchemy, astronomy (astrology), hermetism, and the Cabalah had a gr3at impact on the Rosicrucian movement in the second decade of the seventeenth century. Kepler suggested replacing the word „soul“ by „force,“ that is, the force of magnetism. First he explained the circulating movement of the planets by „moving souls“; later, shifting his philosophy from animism to mechanism, he assumed the presence of a physical force.  When he spoke of „natural, magnetic forces,“ he did not rely on his own investigations but made use of Gilbert’s magnetic philosophy, which postulated that the earth is a body and its nature corresponds to the soul of an animal. The force of the soul (of the planets, the world, or the human body) radiates in all directions with straight beams from the centre of each body in all directions. The human soul originates in the heart and radiates to all points of the body. Kepler identified the beams of the soul with the spiritus of Galenic medicine and put his theory in the contemporary medical context.When the beams from different sources come together, such äs the astral beam with the beam of the human soul, a revelation might result.
The Jesuit scholar Athanasius Kircher (1602-1680) was also very interested in magnetism. As a professor of philosophy, mathematics, Hebrew, and Syriac in Würzburg, he published his first book, Ars magnesia, in 1631, on his own magnetic experiments. Later, he wrote a series of five books on magnetism. In the Ars magna lucis et umbrae (1646) he identified with the „attracting magnets of all things“: it is connected ultimately with the heavens and works like the lode-stone. In this perspective, Isaac Newton’s concept of force, his theory of gravity, combines natural philosophy in the sense of Neoplatonism and Hermetism with the mechanistic, corpuscular theory of matter. Newton’s influence on eigh-leenth-century medicine and science was tremendous. Newton’s ether theory was a basis for many speculations on the so-called imponderables, extremely subtle substances that were supposed to be the physical carriers of all forces. In medicine this meant the forces of electricity, mineral magnetism, the concept of nervous fluid, irritability, and, last but not least, the concept of magnetic fluid (fluidum) as the active power of animal magnetism (or mesmerism).
In contrast to the Paracelsian tradition, this scientific (physical) tradition of magnetism did not include the concept of imagination, in contrast to the Paracelsian tradition, where magnetism and imagination can hardly be separated. The following section will show that van Helmont’s theory of imagination represents a sophisticated refinement of Paracelsian theory.
the power of imagination: van helmont’s theory
Johann Baptist van Helmont (1579-1644), a scholar and a wealthy man, lived in Vilvoorde, near Brussels. In contrast to Paracelsus, who travelled restlessly all his life throughout Europe, van Helmont stayed at home and worked continuously in his chemical laboratory. The most important figure in the Paracelsian movement, van Helmont, was in fact the founder of the so-called chemical philosophy. He was a critical follower of Paracelsus, principally sharing his alchemical approach and his religious attitude as a philosopher and doctor. However, van Helmont rejected the medical astrology of Paracelsus and his analogy of microcosm and macrocosm. Van Helmont concentrated on laboratory work and investigated, for the first time in the history of science, the „gases.“ He coined the term gas, which he probably derived from chaos, a term used by Paracelsus to indicate the vital stuff for animal and human beings as well as the elemental spirits (Elementargeister). Pagel has shown how van Helmont combined chemical experimentation with a sort of natural mysticism. Like Paracelsus, he considered the magnet to be a powerful Instrument for magnetic (so-called sympathetic) cures. When he published De magnetica vulnerum… curatione (On the magnetic eure of wounds) in 1621, he recommended, like many other medical writers of his time, the use of the so-called weapon salve (Waffensalbe). For his criticism of the Jesuits and his obvious support of Paracelsian science, he was sentenced—but not imprisoned—by the church authorities.
In Tumulus pestis (The tomb of the plague), van Helmont explains the origin of diseases. They are caused, he says, by specific seeds, which have their own life principle. This so-called ontological concept of disease resembles the theory of Paracelsus, who also spoke of the seed of a disease (Krankheitssamen). As Pagel stressed: „There is no area in which van Helmont’s inspiration by and dependence upon Paracelsus is as evident as in his ontological theory of disease.“ But in regard to the Paracelsian concept of Imagination, van Helrnont took a different approach: the seed of a disease is activated by a pathogenic image (idea morbosa) hidden within the seed itself. The life spirit (archeus; Lebensgeist) takes on this evil image if it is weakened by bad influences from the outer world.
Those evil images behave like parasites within the body. Imagination, there-fore, means an infection that produces a more or less severe disorder. Imagination (imaginatio) is also called „fanciful animal“ or „animal fancy“ (animal phantasticum; thierische Phantasie), terms that stress its parasitic character. Chapter 11 of the Ttttnulus pestis deals with this topic. In the Latin edition the title of the chapter is Animalphantasticum; in the German edition by Christian Knorr von Rosenroth it is „Von der Thierischen Phantasie: Oder was die Einbildung vor Würckungen hat“(On the animal fancy: Or what effects the imagination has).Compared to Paracelsus, van Helmont develops a much more sophisticated system of how the imagination may influence the human body, mixing contemporary ideas with specific Paracelsian assumptions.
Like his contemporaries and Paracelsus, van Helmont supposed that the imagination of a pregnant woman can produce a birthmark on the fetus. When she is overcome by a certain passion (represented by an image) and touches a part of her body, the analogous part of the child’s body will be imprinted with the image of her passion. But a new aspect appears when van Helmont states that both genders can suffer from hypochondriasis (hypochondriaca, or Wahn-Witzigkeit): „This happens in men as well as in women.“ Men send their images up to the heart and brain, whereas women send them down to the womb, where they provoke passions and emotions. A „slow sadness“ coins an image (ideam), from which „splenetic melancholy“ (melancholia hypochondriaca) in women and jaundice in men come. The spleen corresponding to the vital spirit (lebendiger Geist) of Saturn is, where the imagination usually creates images.
Remarkably, van Helmont also uses astrological ideas to show how celestial bodies influence the physiology of men. The spleen is the seat of Saturn, who may evoke passions. In the spleen (als eine Mutter [like a womb]), the imagination starts disturbing our life. The impression of the mother’s image on the child’s body does not depend on knowledge of the true nature of the image. An inner knowledge within the image is transferred: a „seedal“ science (sämliche Wissenschafft) of, for example, a cherry. Van Helmont emphasizes that the horror of the plague produces an image (idea) of the plague and then the plague itself. The image itself contains the poison that produces the plague, although people do not know its true character. Walter Pagel summarizes van Helmont’s ontological con-ception of disease:
Like any other seed, the morbid semen begotten by the archeus soon achieves independence of its parent. Once externalised from the archeus it attacks and penetrates him from outside like poison. It behaves like a parasite that is hatched in and „obsesses“ a part of the archeus. As such it distracts the archeus from his domestic duties and may thus destroy the organism that is administered by him…. It is, then, the archeus who first conjures up or „imagines“ an idea or image. This rebounds upon him, enshrined in a morbid seed. In the latter the spiritual idea or image has assumed corporality, and brings forth an overpowering monster, that is, the disease.
Once again, van Helmont characterized imagination as a parasitic process by the term animal phantasticum (thierische Phantasie in Knorr’s translation), which means literally „fantastic animal“.
In his tract on the magnetic cure of wounds (1621) van Helmont emphasizes the effectiveness of the „weapon salve,“ a then very popular assumption of natural magic based on „sympathy“ or the „sympathetic“ correspondences of all natural things. Matter and spirit, which are involved in these correspondences, cannot be separated: „the magnet is endowed with various senses and also with imagination, a certain Naturall phansy.” Later, in his Ortus medicinae (published posthumously in 1648), van Helmont once again deals with magnetic-sympathetic remedies analogous to the weapon salve. But he refused the assumption that the magnetic-sympathetic force would derive from the stars. „I derive it from a more obvious thing. Namely from the leading Images (ideis), which are produced by love as a mother or by affection. Therefore it happens, that this sympathetic powder is more effective, when it is handled by this one than by somebody else…. Therefore I estimate the stars of mind in sympathetic remedies more than those in heaven.“
Van Helmont states that man also has a magnet, by which the plague poison is attracted from an infected person. The magnet thus pulls death into the body. But there is an antimagnet preventing the infection: precious stones (sapphire and transparent agate), which are rubbed at special „planet“ locations of the body.In the Ortus medicinae, van Helmont returns to the weapon salve in order to point out the intrinsic connection between imagination and magnetism. Thus, the „imagination of the blood“ is put into the magnetic salve and is awakened by the power of the latter. Because of the healing power in the salve, the imagination of the blood wants to pull all foreign impressions out of the whole blood using a spirilual magnetic tension. The salve requires certain ingredients to become healing and magnetic „by nothing else but its fantasy.“ Van Helmont takes this argu-ment further: he declares that it is possible to produce a magnetic needle only by imagination for intention) of the smith. His imagination imprints the magnetic power on the steel at the moment of the „birth“ of the needle, when it is still glowing: „Therefore those seals are without any power, which are not imprinted by a magician, who has a strong imagination.“ It is not the stars of the macrocosm that influence the steel magnetically, but the „stars of the heaven of the microcosm“, that is, the magician’s imagination.
In this way, van Helmont’s elaborate theory of imagination as a „magnetic“ or „sympathetic“ power constructs a dynamic model of the disease process (and its cure) that includes physiology, pathology, psychopathology, and psychosomatic medicine, in terms of modern medicine. In the Paracelsian perspective of magic medicine, which may also be called chemical philosophy, Imagination remained a major topic of discussion during later periods and anticipated modern trends. The dualism between soul and body introduced by Rene Descartes, the anatomical and physiological research on the nervous System and especially the brain (e.g., by Thomas Willis), the new physical paradigms from Kepler to Newton, and the development of the physical and chemical analysis of the human body all influenced the concepts of Imagination and magnetism. During the Enlightenment, the power of Imagination and the power of magnetism seemed to be self-evident. But in general, they were not systematically combined or even identified until the period of Romanticism in medicine and science, about 1800. Franz Anton Mesmer described „animal magnetism“ as the effect of a physical force, analogous to mineral magnetism, electricity, (invisible) fire, or light. On the other band, his critics in the scientific community rejected his „fluid“ theory and explained the phenomena of the magnetic manipulations by „pure“ Imagination without any transfer of magnetic forces whatsoever.
Imagination was increasingly viewed as an idea fundamentally affecting psychosomatic interaction. The modern theory of mass psychology is based on the concept of transferable ideas. The image (imago) seems to be a contagion, like the germ of an infectious disease. Obviously, much of this tradition has survived in modern cultural sciences, especially in some social theories of psychoanalysis and cultural anthropology (ethnology). Most important remains the concept of suggestion, proposed by Hippolyte Bernheim in the 1880s and adopted by Freud. The original imagery of Paracelsus and van Helmont is more fascinating than the modern explanations with their abstract scientific language. Paracelsus and van Helmont did not distinguish clearly between magnetism and imagination, between matter and mind, physiology and psychology, belief and knowledge, fantasy and reality. Nevertheless, this confusion (as it seems lo us today) was a creative one and contributed to the development of medicine and science in early modern times.
 On the concept of sympathy and its metaphoric use in the history of medicine see Heinz Schott, „Symüathie als Metapher in der Medizingeschichte”, Würzburger medizinistorische Mitteilungen 10 (1992):107-27.
 Heinz Schott, „Die ‚Imagination‘ als historischer Schlüsselbegriff der neuzeitlichen Medizin und (Para)Psychologie,“ in Psychologiegeichichte: Beziehungen zu Philosophie und Grenzgebieten, ed. Jürgen Jahnke, Jochen Fahrenberg, Reiner Stegie, and Eberhard Bauer (Munich: Profil, 1998), 395-403; and Heinz Schott, „Imagination,“ in Der sympathetische Arzt: Texte zur Medizin im 18. Jahrhundert (Munich: C.H.Beck, 1998), 28-38.
 Pierre Le Loyer, ////. Livres des Spectres ou Apparations et Vision d’Esprit, Anges et Demons se monstrans sensiblement aux hommes (Angers: Nepveu, 1586).
 Eugenio Garin, “Phantasia e Imaginatione fra Ficino e Pompnazzi”, in Phantasia-Imaginatio V octavo Colloquio Internationale, ed. M. Fattori and M. Bianchi, Lessico Intellettuale Europeo 46 (Rome: Edizione dell‘ Ateneo, 1988), 3-20.
 Marsilio Ficino, Über die Liebe oder Platons Gastmahl, ed. Paul Richard Blum, 3d ed. (Hamburg: Meiner, 1994), 320 et seq.
 György E. Szyöny, „Tradition of Magic: From Faustus to Dee at European Universities and Courts,“ Cauda Pavonis, n.s. 10 (1991): 1-8.
 Giovanni Battista Della Porta, Natürliche Magie, dos ist Ein ausführlicher und gründlicher Bericht von dm Wunderwerken Natürlicher Dinge (Magdeburg: Rausch, 1612), 262-80.
 The term Od-vampirism (Od-Vampirismus) describes the negative (weakening) powers of persons in the middle of the nineteenth century according to the „Od“ theory (Odlehre) of the German chemist Carl Reichenbach; see Karl Spiesberger. „Justinus Kerners ‚Seherin von Prevorst‘ in Betrachtung esoterischer Tradition und im Lichte psychischer Forschung,“ in Erich Sopp and Karl Spiesberger, Auf den Spuren der Seherin (Sersheim: Osiris, 1953), 64.
 See, e.g, the following encyclopedia articles: J.H. Trede, „Einbildung, Einbildungskraft“; H. Mainusch, „Imagination.“ in Historisches Wörterbuch der Philosophie (1976]; and Silvio Vietta, „Phantasie, Einbildungskraft,“ in Literaturlexikon (1993). In the early eighteenth Century, Imagination was still linked with the idea of a (magnetic) power: see Johann Heinrich Zedler, Grosses vollständiges Universal-Lexikon (1734) und (1735); wehreas in the second half of the nineteenth century this link disappeared: see Jacob Grimm and Wilhelm Grimm, Deutsches Wörterbuch (1862), 3:152-53.
 „|A]ls der ganz himel ist nichts als imaginatio, derselbige wirket in den menschen, macht pesten, kaltwehe und änderst.“ Paracelsus, Sämtliche Werke, I. Abteilung: Medizinische, naturwissenschaftliche und philosophische Schriften, ed. Karl Sudhoff, 14 vols. (1922-33; repr. Hildesheim: Olms, 1971), 1,14:311. Hereafter l will refer to this edition using the Roman numeral to denote the part of the collected edition of the complete works of Paracelsus followed by the volume and page number. All translations from Paracelsus are mine.
 „[N]un was ist imaginatio anderst, als ein sonn im menschen, die dermaßen wirket in sein globum, das ist, do hin sie scheint?“ Ibid.. l, 14:310.
 Walter Pagel, Paracelsus: An Introduction to Philosophical Medicine in the Era of the Renaissance, 2d rev. ed. (Basel: Karger. 1982), 217.
 „Dan kan der magnes an sich zihen stahel, so ist auch ein magnet do in der imagination, wie ein magnet und ein impressio, wie die sonn und wie der himel, der ein menschen macht in der kraft vulcani.“ Paracelsus, Sämtliche Werkt, I, 14:313.
 „[D]er magnet zeucht an sich das eisen on hend und füß. Zu gleicher weis wie also der magnet das sichtig an sich zeucht, also werden auch die corpora unsichtig durch die imagination an sich gezogen, nicht das das corpus hinein gang, sonder das get hinein, das die augen sehen und nicht greiflich ist, also die form und die farbe.“ Ibid., I, 9:290.
ren ist aus der imagination.“ Ibid., l, 14:314.
 „Und das herauf kompt in himel, ist imaginatio und wider herab felt, ist impressio, die geboten ist aus der imagination.“ Ibid., I, 14:314.
 Ibid., 1,14:317. See Heinz Schott, „‚Invisible diseases’—Imagination and Magnetism: Paracelsus and (he Consequences,“ in The Man and His Reputation, His Ideas and Their Transformation, ed. Ole Peter Grell (Leiden: Brill, 1998), 309-21.
 Paracelsus, Sämtliche Werke, l, 9:280.
 „|D|as sieden himel vergiften, das er etlichen pestilenz gibt, nach dem ir glaub ist.“ Ibid.
 „|D|u findest ein man, der kan reden, das im alle well zulauf, und hört im zu. nu wiß, das das maul ein magnet ist, zeucht an sich die leut in der kraft.“ Ibid., l, 9:363.
 Oswald Groll. Chymisch Kleynod (Frankfurt: Schönwetter, 1647), 86.
 Suzanne Kelly,“WilliamGilbert“in Diaionary of ScientificBiography (1972), 5:396-401.
 Heinrich Feldt,“Der Begriff der Kraft im Mesmerismus: Die Entwicklung des physikalischen Kraftbegriffes seil der Renaissance und sein Einfluß auf die Medizin des 18. Jahrhunderts“ (medical thesis, Bonn, 1990), 20.
 Neither did Franz Anton Mesmer, when he explained „animal magnetism“ about two hundred years laler! „Imagination“ or Einbildungskraft had a pejorative meaning then: il described only a subjective, psythic impression without a physical, detectable effect.
 Feldt, „Der Begriff der Kraft im Mesmerismus.“ 9-30. Feldt’s treatise shows very well how important the concept of (magnetic) force was to establish a theory of a psychic force in regard to mesmerism.
 Ibid., 13.
 Ibid., 24-25.
 Hans Kangro, „Athanasius Kircher“ in Dictionary o fScientific Biography (1973), 7:374-78.
 Cf. Feldt, „Der Begriff der Kraft im Mesmerismus,“ chaps. 2 and 3.
 Heinz Schott, „Paracelsismus und chemische Medizin: Johann Baptist van Helmont zwischen Naturmystik und Naturwissenschaft,“ in Meilensteine der Medizin, ed. Heinz Schott (Dortmund: Harenberg, 1996).
 Allen G. Debus, The Chemical Philosophy: Paracelsian Science and Medicine in the Sixteenth and Seventeenth Centuries (New York: Science History Publishers, 1977).
 Walter Pagel, „Johannes Baptist» van Helmont als Naturmystiker,“ in Epochen der Naturmystik: Hermetische Tradition im wissenschaftlichen Fortschritt, ed. A. Faivre and R.C. Zimmermann (Berlin: E. Schmid, 1979), 169-211.
 Waller Pagel. loan Baplista van Hetmont: Reformer of Science and Mediane (Cambridge: Cambridge University Press, L 982), 149.
 J.B. van Helmont, Opuscula Inaudita (1644; repr. Brüssels: Culture et Civilisation, 1966).
 Christian Knorr von Rosenroth. Aufgang der Amney-Kunu, das ist: Noch nie erhörte Grund-Lehren von der Natur… (1683; repr. Munich; Kösel-Verlag, 1971), 591-95. [German translation of Latin and Dutch works of van Helmont]. Quotations are referenced to Knorr’s German edition; they have been translated into English by the author.
 The section is entitled „On the imagination in men“; cf. Knorr von Rosenroth, Aufgang der Artzney-Kunst, 592.
 The fact that both genders can be affected is reminiscent of Sigmund Freud’s assumption of „male hysteria“ in quite another medico-historical context.
 Cf. Knorr von Rosenroth, Aufaing der Artzney-Kunst, 993/12.
 Cf. Pagel. Joan Baplista van Helmant, 144.
 Cf., ibid., 10.
 Van Helmont refers to the tract on the „sympathetic powder“ by Mohy, published in
1639.; cf. Knorr von Rosenroth, Aufgang der Artzney-Kunst, 1002/2.
 Ibid., 1001/4.
 Ibid., 1018/17.
 Ibid., 1040/166.
 Ibid., 1041/170.
 The reflex model by Descartes and the brain research by Willis are thoroughly analyzed and illustrated in Edwin Clarke and Kenneth Dewhurst, Die Funktionen des Gehirns: Lokalisationstheorien von der Antike bis zur Gegenwart (Munich: Moos, 1973), 69-74.
 Cf. Heinz Scholl, „Über den ‚thierischen Magnetismus‘ und sein Legilimationsproblem: Zum 250. Geburtstag von F.A. Mesmer (1734-1815],“ Medizinhistorisches Journal 21 (1986): 104-11.
 The transfer of pathogenic images in terms of mass psychology was an important explanation for the „emotional plague“ produced by crowds, e.g., in revolutions or similar mass movements. This was pointed out, e. g. by Gustave LeBon in the late nineteenth cenmtury and Wilhelm Reich in the early twentieth century; on the problem of (suggestive) psychic infection see Heinz Schott, „Die ‚Suggestion‘ und ihre medizinhistorische Bedeutung,“ in Bausteine zur Medizingeschichte; Heinrich Schipperges zum 65. Geburtstag, ed. Eduard Seidler and Heinz Schott, Sudhoffs Archiv; vol. 24 (Stuttgart Franz Steiner, 1984), 111-21.