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Fludd, Robert

Fludd, Robert

(b. Milgate House, Bearsted, Kent, England, 1574; d. London, England, 8 September 1637)

alchemy, medicine.

A son of Sir Thomas Fludd and Elizabeth Andros, Fludd came from a well-to-do family connected with the court. His father had been treasurer of war to Queen Elizabeth in France and the Low Countries, and Fludd himself was later to speak of James I as his patron. He attended St. John’s College, Oxford, from which he graduated B.A. in 1596 and M.A. in 1598. The following six years he spent as a student of medicine, chemistry, and the occult sciences in France, Germany, Spain, and Italy. On his return to England, Fludd became a member of Christ Church, Oxford, where he received M.B. and M.D. degrees in 1605. After moving to London he sought admission as a fellow to the Royal College of Physicians. Largely because of his contempt for the Galenic system and his insolent manner he repeatedly failed the examination, but he was finally elected a fellow on 20 September 1609 and served as censor in 1618, 1627, 1633, and 1634. His London practice was highly successful, and he was wealthy enough to maintain his own apothecary and a secretary.

Although Fludd had already written a great deal, he had as yet published nothing when the appearance of the Fama fraternitatis (1614) initiated a Continental debate over the authenticity of the Rosicrucian texts. When the eminent iatrochemist Andreas Libavius attacked the Rosicrucians, Fludd rose to their defense in a short Apologia (1616), which reappeared in considerably expanded form as the Tractatus apologeticus (1617). Also in 1617 he began to publish his massive description of the macrocosm and the microcosm, the Utriusque cosmi maioris scilicet et minoris, metaphysica, physica atque technica historia. Here and in his other publications Fludd constantly attacked Aristotle, Galen, and the universities, which to him seemed dedicated to preserving the authority of the ancients. He sought instead a new understanding of nature based on Christian principles. His guides were primarily the Mosaic books of the Bible (especially the Creation account in Genesis, which he interpreted as a divine alchemical process) and the Hermetic and Neoplatonic works of late antiquity and the Renaissance, which seemed to mirror the Christian truths. Although Fludd was quite willing to use observational and experimental evidence, he thought that the eternal truths of Scripture and the mysteries of the ancient occultists carried far more weight than the evidence of the senses.

Fludd pictured the universe in terms of a double centrality, a central earth surrounded by the sun, moon, and planets (whose motions were explained by mechanical analogies) and a central sun situated midway between the center of the earth and God. Beyond the fixed stars were the heavens and the region of divinity. He suggested further that relative distances in the heavens might best be found through a study of the celestial monochord and the mathematical musical harmonies.

Fludd sought divine truths in the macrocosm-microcosm analogy and the doctrine of sympathy and antipathy. There was no question that man and divinity were linked through nature. Fludd placed the seat of the Holy Spirit in the sun, from which emanated light and the spirit of life. Life on earth was possible for man only through inspiration of this spirit from the atmosphere—a spirit which he identified as an aerial saltpeter. The source of this spirit affects the human body. Because of the circular motion of the sun, the spirit must have a circular motion impressed on it. Therefore the blood, which carries the spirit, must also circulate. This mystical description of the circulation of the blood was presented by Fludd in his Anatomiae amphitheatrum (1623). Yet Fludd was a trained anatomist and had watched Harvey carry out dissections at the Royal College of Physicians. In his later writings he referred to those dissections, and he was the first to support Harvey’s De motu cordis in print, thinking that the views of his friend confirmed his own cosmological concept of the circulation of the blood (1629).

As a Hermeticist, Fludd had a special interest in the elements. In the first chapter of Genesis he found evidence only for darkness, light, and water as true elements. Therefore the four elements of Aristotle and the three principles of Paracelsus could at best be considered as secondary elements. Heat and cold corresponded to his elements of light and darkness, and he repeatedly employed a graduated thermoscope to show their effects. Here he seemed to have visual evidence of the doctrine of expansion and contraction. Similarly, Fludd entered into the contemporary dispute over the “weapon salve,” which was an important test for the validity of sympathetic medicine. In the course of this debate he described William Gilbert’s magnetic experiments in detail because they seemed to give valid examples of action at a distance. Here was support by analogy for the truth of the action of the weapon salve. And yet, although Fludd condemned the medicine of the Galenists in general, he accepted the humoral system of disease, which he described in relation to astral influences affecting the body.

The most detailed works on the macrocosmmicrocosm universe in the early seventeenth century, Fludd’s writings attracted a great deal of attention and controversy. Kepler attacked him after reading his views on the macrocosm and the mathematical harmony of the divine monochord. Mersenne wrote against him several times and was instrumental in having Gassendi write a detailed refutation of Fludd’s philosophy. Fludd, in turn, found time to answer these opponents and others in detail. His own work was supported by a number of Continental authors, and in England his writings were proposed as a basis for a Christian understanding of the universe by John Webster in his plea for a reformation of the English universities in 1654.


I. Original Works. The most complete list of Fludd’s works is in J. J. Manget, Bibliotheca scriptorum medicorum (Geneva, 1731), I. pt. 2, 298. J. B. Craven’s Doctor Robert Fludd (Robertus de Fluctibus). The English Rosicrucian. Life and Writings (Kirkwall, 1902; repr. New York, n.d.) also describes Fludd’s complex bibliography.

Fludd’s first publication, the Apologia compendiaria Fraternitatem de Rosea Cruce suspicionis maculis aspersam veritatis quasi Fluctibus abluens et abstergens (Leiden, 1616), was expanded from 23 to 196 pages in the 2nd ed., Tractatus apologeticus integritatem Societatis de Rosea Cruce defendens (Leiden, 1617). The work appeared in German translation by Ada Mah Booz (A[dam] M[elchior] B[irkholz]) as Schutzschrift für die Aechtheit der Rosenkreutzergesellschaft . . . (Leipzig, 1782). Also from this period are the Tractatus theologo-philosophicus (Oppenheim, 1617) and the first part of the Utriusque cosmi maioris scilicet et minoris, metaphysica, physica atque technica historia, subtitled De macrocosmi historia (Oppenheim, 1617). The second part appeared as the De naturae simia seu technica macrocosms historia . . . (Oppenheim, 1618).

The reaction to these works was immediate, and Fludd defended both the Rosicrucians and his own writings to James I in his “Declaratio brevis” (ca. 1617). He returned to the same theme in “A Philosophicall Key . . . Wrighten as a Declaration Unto the Distrustfull and Suspicious, First to Manÿfest, That the Authour Flÿeth on his Owne Wings, and Then to Purifÿ the Adulterat Breath of Spurious Reports as Well of the Ignorant, as Envious Person.” This work, probably composed between 1618 and 1620, was also dedicated to the king. Both MSS are currently being prepared for publication by Allen G. Debus.

Kepler attacked Fludd in an appendix to the Harmonices mundi (Linz, 1619), which was answered by Fludd in his Veritatis proscenium . . . seu demonstratio quaedam analytica, in qua cuilibet comparationis particulae, in appendice quadam a J. Kepplero, nuper in fine harmoniae suae mundanae edita, facta inter harmoniam suam mundanam, et illam R. F., ipsissimis veritatis argumentis respondetur (Frankfurt, 1621). Kepler replied in his Prodromus dissertationum cosmographicum . . . Item ejusdem J. Kepleri pro suo opere Harmonices mundi, apologia adversus demonstrationem analyticam Roberti de Fluctibus (Frankfurt, 1621–1622), which included a reprint of the Mysterium cosmographicum (1596); this, in turn, was answered by Fludd in the Monochordum mundi replicatio R. F. . . . ad apologiam . . . J. Kepleri adversus demonstrationem suam analyticam nuperrime editam, in qua Robertus validoribus Joannis objectionibus harmoniae suae legi repugnantibus, comiter respondere aggreditur (Frankfurt, 1622).

Fludd and the Hermeticists were attacked by Mersenne in the Quaestiones celeberrimae in Genesim . . . (Paris, 1623), to which he replied in the Sophiae cum moria certamen (Frankfurt, 1629). Gassendi’s Epistolica exercitatio, in qua principia philosophiae Roberti Fluddi, medici, reteguntur, et ad recentes illius libras adversus R. P. F. Marinum Mersennum . . . respondetur (Paris, 1630) was answered at length by Fludd in the Clavis philosophiae et alchymiae Fluddanae sive Roberti Fluddi armageri, et medicinae doctoris, ad epistolicam Petri Gassendi theologi exercitationem responsum (Frankfurt, 1633).

Of lesser importance was Patrick Scot’s The Tillage of Light (London, 1623), which was answered by Fludd in “Truth’s Golden Harrow,” first printed with commentary by C. H. Josten in Ambix, 3 (1948), 91–150. Fludd’s defense of the weapon salve was criticized by a little-known pastor, William Foster, in the Hoplocrisma-Spongus: Or a Sponge to Wipe Away the Weapon-Salve (London, 1631); in reply to this there appeared Doctor Fludds Answer Unto M. Foster. Or, the Squeesing of Parson Fosters Sponge, Ordained by Him for the Wiping Away of the Weapon-Salve (London, 1631).

From Fludd’s other major works three additional titles may be singled out: the Anatomiae amphitheatrum effigie triplici, more et conditione varia disignatum (Frankfurt, 1623), in which Fludd described both the scientific and the mystical anatomy of the body; the Pulses (Frankfurt, n.d. [completed 1629]), which forms part of the Medicina Catholica, seu mysticum artis medicandi sacrarium and includes Fludd’s first defense of Harvey; and the Philosophia Moysaica (Gouda, 1638), later trans. into English (London, 1659), which summarizes Fludd’s cosmological views and then goes into the weapon-salve problem and magnetism at great length. A French translation of part of the work on the macrocosm exists: Étude du macrocosme, annotée et traduite pour la première fois par Pierre Piobb. Traité d’astrologie générale (De astrologia) (Paris, 1907).

II. Secondary Literature. The standard biography is that of J. B. Craven cited above. Additional material is given by Josten in the introduction to his “Truth’s Golden Harrow” and in his “Robert Fludd’s Theory of Geomancy and his Experiences at Avignon in the Winter of 1601 to 1602,” in Journal of the Warburg and Courtauld Institutes, 27 (1964), 327–335. A general account of Fludd’s work is in Allen G. Debus, The English Paracelsians (London, 1965; New York, 1966), pp. 105–127; and in “Renaissance Chemistry and the Work of Robert Fludd,” in Allen G. Debus and Robert P. Multhauf, Alchemy and Chemistry in the Seventeenth Century (Los Angeles, 1966), pp. 1–29.

The Fludd-Kepler exchange is discussed by W. Pauli in “The Influence of Archetypal Ideas on the Scientific Theories of Kepler,” in C. G. Jung and W. Pauli, The Interpretation of Nature and the Psyche, trans. by Priscilla Silz (New York, 1955), pp. 145–240. An older but still basic study is R. Lenoble, Mersenne ou la naissance du mécanisme (Paris, 1948), pp. 103–105, 367–370, and passim. Frances A. Yates discusses Fludd’s controversies in her Giordano Bruno and the Hermetic Tradition (Chicago, 1964), pp. 432–455, and has also shown Fludd’s connection with the Vitruvian revival in England and the work of John Dee in her Theatre of the World (London, 1969), pp. 42–79. The Gassendi controversy is discussed by L. Cafiero in “Robert Fludd e la polemica con Gassendi,” in Rivista di storia della filosofia, 19 (1964), 367–410, and 20 (1965), 3–15.

Fludd’s physiological concepts and his defense of Harvey are described in Walter Pagel’s “Religious Motives in the Medical Biology of the 17th Century,” in Bulletin of the Institute of History of Medicine, 3 (1935), 97–128, 213–231, 265–312 (see 265–297); and his William Harvey’s Biological Ideas (Basel-New York, 1967), pp. 113–118; in Allen G. Debus, “Robert Fludd and the Circulation of the Blood,” in Journal of the History of Medicine and Allied Sciences, 16 (1961), 374–393; and “Harvey and Fludd: The Irrational Factor in the Rational Science of the Seventeenth Century,” in Journal of the History of Biology, 3 (1970), 81–105. Some aspects of Fludd’s defense of the Rosicrucians are discussed by Debus in “Mathematics and Nature in the Chemical Texts of the Renaissance,” in Ambix, 15 (1968), 1–28. Fludd’s relation to the traditional art of memory is the subject of research by Frances A. Yates in The Art of Memory (Chicago, 1966), pp. 320–367; C. H. Josten discusses Fludd’s alchemical experiment on wheat, taken from the “Philosophicall Key,” in Ambix, 11 (1963), 1–23; his system of music is described by Peter J. Ammann in “The Musical Theory and Philosophy of Robert Fludd,” in Journal of the Warburg and Courtauld Institutes, 30 (1967), 198–227. His relationship to Milton is the subject of research by Denis Saurat in Milton et le matérialisme chrétien en Angleterre (Paris, 1928); and the relationship of Fludd’s thermoscope to the thermometer is described by F. Sherwood Taylor in “The Origin of the Thermometer,” in Annals of Science, 5 (1942), 129–156 (see 142–150).

Robert Fludd’s views on educational reform and the meaning of a new science are taken up in Allen G. Debus, The Chemical Dream of the Renaissance (Cambridge, 1968), pp. 20–23; and Science and Education in the Seventeenth Century. The Webster-Ward Debate (London-New York, 1970), pp. 23–26. Other aspects of Fludd’s work are described by Debus in “The Paracelsian Aerial Niter,” in Isis, 55 (1964), 43–61; “Robert Fludd and the Use of Gilbert’s De magnete in the Weapon-salve Controversy,” in Journal of the History of Medicine and Allied Sciences, 19 (1964), 389–417; and “The Sun in the Universe of Robert Fludd,” in Le soleil à la Renaissance—sciences et mythes, colloque international tenu en avril 1963 . . . (Brussels, 1965), pp. 259–278.

Allen G. Debus

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Fludd (or Flud), Robert (1574-1637)

Fludd (or Flud), Robert (1574-1637)

English Rosicrucian and alchemist who was born at Milgate House, in the parish of Bearsted, Kent, England. His father was Sir Thomas Fludd, a knight who enjoyed the patronage of Queen Elizabeth and served her for several years as "treasurer of war in the low countries."

At age 17 Robert entered St. John's College, Oxford. Five years later he took his bachelor of arts degree. Soon afterward he decided to take up medical science and left England to study on the Continent, visiting France, Spain, Italy, and Germany, supporting himself as a teacher. Upon returning home his alma mater, Oxford, conferred on him the degrees of bachelor of medicine and doctor of medicine; five years later, in 1609, he became a fellow of the College of Physicians.

Having prepared himself thoroughly for the medical profession, Fludd went to London and took a house in Fenchurch Street. He soon gained an extensive practice, his success attributable not merely to his genuine skill but also to his having an attractive and even magnetic personality. Although he kept busy with his medical practice, Fludd found time to write at length on medicine. He also became an important and influential member of the Fraternity of the Rosy Cross and began experiments in alchemy. He preached the great efficacy of the magnet, of sympathetic cures, of the weapon salve, and declared his belief in the philosophers' stone, the universal alkahest or solvent, and the elixir vitae.

As a writer, Fludd represented a school of medical mystics, which laid claim to the possession of the key to universal sciences. Fludd maintained that all things were animated by two principles: condensation, the boreal, or northern virtue; and rarefaction, the austral, or southern virtue. He asserted that the human body was controlled by a number of demons, that each disease had its peculiar demon, and each demon his particular place in the frame of humanity, and that to conquer a disease say, in the right legone must call in the aid of the demon who ruled the left, always proceeding by this rule of contraries. As soon as the doctrines of the Rosicrucians were promulgated in the early seventeenth century Fludd embraced them with eagerness, and when several German writers attacked them he published a defense in 1616, under the title Apologia Compendiaria Fraternitatem de Rosea-Cruce Suspicionis et Infamiæ Maculis Aspersam Abluens, which procured him a widespread reputation as one of the apostles of the new fraternity.

Fludd met with the usual fate of prophets and was lustily denounced by a host of critics, including Pierre Gassendi and Johann Kepler. Fludd retorted in an elaborate treatise, Summum Bonum, quod est Magiæ, Cabalæ, Alchimiæ, Fratrum Roseæ-Crucis Verorum, et adversus Mersenium Calumniatorem. At a later period he made an adventurous attempt to identify the doctrines of the Rosicrucians with what he called the "philosophy of Moses" in his new volume, Philosophia Mosaica, in quâ sapientia et scientia Creationis explicantur (1638), and wrote numerous treatises on alchemy and medical science. His Philosophia Mosaica is notable for a discussion of the relationship between a rod and the mineral and vegetable world (i.e., the divining rod or dowsing rod). He also founded an English school for Rosicrucians.

Fludd was one of the high priests of the magnetic philosophy and learnedly expounded the laws of austral medicine, the doctrines of sympathies, and the fine powers and marvelous effects of the magnet. According to his theory, when two men approach each other their magnetism is either active or passive, that is, positive or negative. If the emanations that they send out are broken or thrown back, there arises antipathy, or magnetismus negativus; when the emanations pass through each other, positive magnetism is produced, for the magnetic rays proceed from the center to the circumference. Humans, like the earth, have their poles, or two main streams of magnetic influence, according to Fludd's theory. Like a miniature world, humans are endowed with a magnetic virtue that is subjected to the same laws as those of the universe. How these principles could be developed in the cure or prevention of disease is described at length in Fludd's books.

Fludd died September 8, 1637, at a house in Coleman St., London, to which he had moved a few years before. Before his death he had won a fairly wide reputation founded on his chemical ability and had also written a number of books that contributed to the establishment of Rosicrucianism in Europe.


The Dictionary of National Biography. London: Oxford University Press, 1953.

Fludd, Robert. Medicina Catholica. Frankfurt: William Fitzer, 1629.

. Monochordum Mundi Symphoniacum. Frankfurt, 1622.

. Philosophia Mosaica, in quâ sapientia et scientia Creationis explicantur.

Gouda: Peter Rammazen, 1638. Translated as Mosaicall Philosophy. London: Humphrey Moseley, 1659.

. Tractatus Apologeticus integritatem Societatis de Rosae Cruce defendans. Leiden: Gottfried Basson, 1617.

. Veritatis Proscenium. Frankfurt: Johann Theodore de Bry, 1621.

Godwin, Joscelyn. Robert Fludd: Hermetic Philosopher and Surveyor of Two Worlds. Boulder, Colo.: Shambhala, 1979.

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Fludd, Robert

Robert Fludd, 1574–1637, English mystic philosopher. Educated at Oxford and on the Continent, he became a London physician. Strongly influenced by the mystical doctrines of Paracelsus, he attempted to reconcile these speculations with the new science of the 17th cent. From his study of Paracelsus he arrived at the theory that spiritual and physical truth are identical. His mystical pantheism centered in God as the all-pervading form of which the world and man are manifestations. He held that the dualism of light and darkness is inherent in all things. The best-known English representative of the Rosicrucians, he spread their ideas in a number of medico-theosophical books. His major works include Utriusque cosmi, maioris scilicet et minoris, metaphysica, physica atque technica historia (1617–21) and Philosophia Moysaica (1638; tr. Mosaicall Philosophy, 1659).

See F. A. Yates, Theatre of the World (1969); W. Huffman, Robert Fludd and the End of the Renaissance (1989).

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