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Severinus,Petrus (or Peder Sørenson)


(b. Ribe, Jutland, Denmark, 1542 [or 1540]; d. Copenhagen, Denmark, July 1602)

chemistry, medicine.

Severinus attended the University of Copenhagen, where he lectured on Latin poetry at the age of twenty. After studying medicine briefly in France, he returned to Copenhagen to take his Master of Arts degree. He was officially appointed Professor Paedagogicus, and, with the offer of financial support from the University of Copenhagen, he set out with Johannes Pratensis (also a noted sixteenth-century Paracelsist) to study abroad. From 1565 to 1571 Severinus traveled throughout Germany, France, and Italy, attending various universities. Although he first matriculated at the University of Padua, he took his M.D. degree in France. Later in Florence, he completed his major work, Idea medicinae philosophicae (1571), which he dedicated to the Danish King, Frederick II, a monarch genuinely interested in the sciences. On his return home Severinus was appointed canon of Roskild and became a physician to the court, a post he held for the next three decades. In 1602 he was offered the chair of medicine at the University of Copenhagen, but he died of the plague before the appointment officially began.

Severinos was widely known in the iatrochemical of his time. In Denmark he was closely associated at court with Tycho Brahe, who was claimed by sixteenth- and seventeenth-century chemists as a leading authority in this field. The writings of Severinus attest to his close relationship with the Paracelsians Livinius Battus and Theodor Zwinger the elder. The English iatrochemist Thomas Moffett, who visited Denmark in 1582, dedicated his important De jure et praestantia chemicorum medicamentorum (1585) to Severinus.

Only two of Severinus’ many papers were published: Idea medicinae philosophicae (1571) and Epistola scripta Theophrasto Paracelso (1572). The latter, a short panegyric, was written thirty years after the death of Paracelsus and it reached its greatest audience when it was included in the Latin edition of Paracelsus’ works (1658). Far more important is the Idea medicinae philosophicae, which purported to contain the “entire doctrine of Paracelsus, Hippocrates, and Galen.” Although earlier syntheses of the Paracelsian corpus had been written by Leo Suavius (1568) and Albert Wimpenaeus (1569), the work of Severinus was immediately accepted as one of the most authoritative documents of the Paracelsian school.

The Idea was a defense of the Paracelsian doctrines in opposition to the traditional medicine. In his attack Severinus labeled Galen as little more than a compiler who had been forced to arrange the work of his predecessors into some sort of order; seeking a unifying principle for this task, Galen had chosen the methods of the geometricians. His attempt to make medicine a part of geometry, with its own principles, axioms, and mathematical explanations, had been finally disproved, Severinus argued, only in recent years, when a number of new diseases had ravaged the Continent. Because they could not be controlled by physicians trained only in the traditional methods, it was therefore proper to seek something new and more effective. The answer was to be found in the medicine that was the glory of Paracelsus, a scholar whose method was devoid of the “mathematical” approach of the Galenists. In contrast, the truths to be found in his work were based on the fresh observations of the chemists. In one of the most frequently quoted passages of the sixteenth-century scientific literature, Severinus tells his readers to discard their books and to seek a knowledge of nature through personal experience.

The Epistola indicates in a few pages those Paracelsian texts known to Severinus, while the Idea shows just how deeply steeped in those sources he was. He fully accepted Paracelsus’ endorsement of the macrocosm-microcosm universe; and he wrote that man has within him rivers, seas, mountains, and valleys in a fashion analogous to the greater world. Severinus accepted the doctrine of signatures and firmly condemned the humoral pathology of the ancients. Again, like Paracelsus, he broke with traditional medicine in affirming that the harmony of nature requires that like must cure like. In contrast, the Galenists insisted that contraries cured.

Much of the Idea Medicinae philosophicae is devoted to the elements and the principles. The influence of traditional alchemy may be seen in the acceptance of both material and insensible elements, while the inconsistencies of Paracelsus regarding the relationship of the Aristotelian elements and the Paracelsian principles also is mirrored. Severinus’ view of the universe was vitalistic and he believed that naturalists should seek out the vital principle in all substances. He stated that the elements contained certain forces, or astra, that, in connection with the chemical principles, formed semina. These semina were to be found in all parts of a given body-in man, however, they were perfected in the generative organs. The seed was properly called “astral” in nature because it had the magisterial power of life, which could not be destroyed even through the processes of putrefaction and dissolution.

As Pagel has shown, Severinus was the most eloquent exponent of epigenesis in the period between Aristotle and Harvey. He believed that the Semen could give rise to a complex organism, not by virtue of the matter present but through its internal endowment, an intrinsic “knowledge” within it. While his views were significant, they were not based on embryological observations. In his role as defender of Paracelsus, Severinus placed strong emphasis on the supremacy of the heart because of its relationship to the vital spirit. Nevertheless, to him the role of the heart was somewhat less important than that of the blood, since the essential life force reached all parts of the body through this vehicle. Thus, although Severinus adopted the hard line of the Paracelsians against the ancients, his views on the primacy of the heart and the blood-as well as his espousal of epigenesis-show an Aristotelian influence and also mark him as a significant precursor of Harvey.

As the first major synthesis of the Paracelsian corpus, the Idea medicinae philosophicae was highly influential. Printed three times between 1571 and 1660, it was widely quoted not only by adherents of the new Paracelsian medicine but also by its opponents. Thomas Erastus wrote against Severinus in his De chymicorum cum Aristotelicis et Galenicis consensu ac dissensu liber (1619) Francis Bacon thought higly of the ability of Severinus, and he regretted only that he had devoted his time and talent to supporting the “useless” opinions of Paracelsus. Perhaps the greatest impact of the Idea medicinae philosophicae is to be found in the work of William Davison, who was appointed the first lecturer in chemistry at the Jardin des Plantes in Paris. In 1660 Davison’s Commentariorum in...Petri Severini Dani Ideam medicinae philosophicae...prodromus was published along with the much shorter original text of the Idea. A condensed commentary, also by Davidson, appeared in 1663.


I. Original Works. Epistola scripta Theophrasto Paracelso: In qua ratio ordinis et nominum, adeoque totius philosophiae adeptae methods compendiose et erudite ostenditue a Petro Severino Dano, philosophiae et mediecine doctore (Basel, 1572) is most conveniently found in the Latin Opera omnia of Paracelsus, Fridericus Bitiskius, ed... I (Geneva, 1658), 4v–2r. The idea medicinae philosophical. Continents fundamenta totius doctrine Paracelsicar Hippocraticae & Galenicae (Basel, 1571: 2nd ed.. Erfurt, 1616) was reprinted (The Hague, 1660) with a long commentary by William Davidson, the Commentariorum in ... Petri Severini Dani Ideam medicinae philosophicae... prodromus Davidson’s brief commentary entitled Commentraia in Ideam medicinae philosophicae Petri Severini Dani, medici incomparabilis & philosophi sublimis (The Hague, 1663) is an entirely different work. A contemporary English trans. probably made by A. Bartlte ca. 1600, of the Idea medicinae philosophicae exists in MS at the British Museum (Sloane MS 11).

II. Secondary Literature. The secondary literature on Severinus is scanty, and Kurt Sprengel, Versuch einer pragmatischen Geschichte der Arzneikunde, 2nd ed., 5 vols. (Halle, 1800–1803), III (1801), 408–413, remains of interest. Important material on the Scandinavian Paracelsians is in Sten Lindroth, Paracelsismen i Sverige till 1600-talets mitt (Uppsala, 19430, 21–25, and passim; more recent are Eyvind Bastholm, “Petrus Severinus (1542–1602). A Danish Paracelsist,” in Proceedings of the XXI international Congress of the History of Medicine (Siena, 1968), 1080–1085; and “Petrus Severinus (1542–1602). En dansk paracelsist,” in Särtryck ur Sydsvenska medicinhistoriska sällskapets arsskrift (1970), 53–72.

On the relationship of the work of Severinus to the Paracelsian corpus, see Walter Pagel, Paracelsus. An Introduction to Philosophical Medicine in the Era of the Renaissance (Basel-New York, 1958), passim. More specifically, Pagel has investigated Severinus as a precursor of William Harvey in William Harvey’s Biological Ideas. Selected Aspects and Historical Background (Basel-New York, 1967), 239–347.

The relationship of Severinus’ views on mathematics to those of other Paracelsians is discussed in Allen G. Debus, “Mathematics and Nature in the Chemical Texts of the Renaissance.” in Ambix, 15 (1968), 1–28, 211: and a summary of his thought from the standpoint of the chemist is included in J. R. Partington, A History of ChemistryII (London, 1961) 163–164.

The impact of the work of Severinus on the contemporary English medical literature is treated in Allen G. Debus, The English Paracelsians (London, 1965; New York, 1966), 20 and passim. The extent of his influence throughout European medical circles is reflected in the many references in John Ferguson, Bibliotheca chemica (Glasgow, 1906; repr. London, 1954), 11, 378–379.

Allen G. Debus

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