A Philosophical Path for Paracelsian Medicine: The Ideas, Intellectual Context, and Influence of Petrus Severinus (1540-1602) (review)

The Paracelsian and Danish royal physician Petrus Severinus complained, "If we can make more potent [drugs], extracted from metals and minerals, . . . I ask, what age except this one will oppose our efforts?" (115). Indeed, early modern attempts to prepare and prescribe drugs forged in the alchemical laboratory often faced vehement opposition by the university-trained physicians who were weaned on the humoral theory and herbal materia medica of Galen. The orthodox Galenists disdained not only the "chemical poisons" of the Paracelsians, but also their theoretical speculations. After all, the Paracelsians dismissed the belief that disease was the result of humoral imbalances, and promoted both the analogy of microcosm (the human) and macrocosm (the natural world, including the stars), and the idea that diseases were essences or actual beings.

Severinus was prescient in his prediction that chemical medicine would become popular, but—as Jole Shackelford notes in the introduction to his A Philosophical Path for Paracelsian Medicine—the concepts of Paracelsus and his followers continue to remain peripheral to the grand narratives of early modern intellectual history. This remains the case despite the illuminating studies of such scholars as the late-Enlightenment medical historian Kurt Polycarp Sprengel, Walter Pagel, and Allen Debus. Thus, Shackelford sheds much needed light on this significant strand of sixteenth- and seventeenth-century science and medicine. Via text-oriented study, particularly of Severinus's Idea medicinæ philosophicæ (Ideal of Philosophical Medicine), Shackelford provides a long-awaited and meticulous biographical account of Severinus and explains with refreshing clarity the sources and speculative theory behind his brand of chemical medicine. Like such recent scholars as Michael Walton and Charles Gunnoe, Shackelford presents Paracelsianism as an ideology, duly noting that the ideas of Severinus, reflecting the reception of Paracelsus in general, were frequently accepted or rejected on religious grounds.

To begin, Shackelford establishes Severinus's importance, noting that the medical author and Wittenberg professor Daniel Sennert wrote in 1619 that most iatrochemists followed in the steps of Severinus, who had molded Paracelsus's ideas into a coherent philosophy. Shackelford then traces the story of how Severinus—after studying at such universities as Padua and Paris—joined his friend Pratensis (a recognized Paracelsian) and Tycho Brahe in bringing an increasingly eclectic Denmark up to continental cultural and intellectual standards. Unfortunately, Severinus's appointment as physician to the king distracted him from completing most of his research projects, but he had already left for posterity his Idea medicinæ, published in 1571.

As Shackelford writes, the Idea medicinæ promoted Severinus's belief that Paracelsian medicine was not only an alternative to humoral medicine, but also promised to cope better with "new" fevers. Also, Severinus invested Paracelsianism with authority by emphasizing its ancient forebears and by arguing that Paracelsus was the latest in the line of prisca theologia—one of the few to "ascend to the inner chambers of the Mosaic mysteries" (57). In his amalgamation of Neoplatonism, the Hippocratic tradition, and Paracelsus, Severinus's featured doctrine was efficient causation, or "semina theory." Unlike Robert Boyle's inertial, material corpuscles and their active principles, Severinus's semina were "intrinsically formal and immaterial, and were logically and ontologically prior to matter" (17). The characteristics of these "loci," which accounted for all change in the subvisible world, could be observed through chemical analysis, and they were uniquely attractive to Christians, who were drawn to Severinus's Paracelsian interpretation of Genesis and his idea that when the predestinations contained in the semina are completed, the world will reach its end.

Shackelford engages the reader with such fascinating topics as why Tycho—who was not just an astronomer, but also a student of alchemy—departed Denmark, and how Paracelsians were involved in the effort to improve the Danish Bible by "cleansing" it of non-Lutheran elements. Very welcome too is Shackelford's discussion of the neglected topic of Paracelsian therapeutics, especially his evaluation of...