Paracelsianism (also Paracelsism; German: Paracelsismus) was an early modern medical movement based on the theories and therapies of Paracelsus. It developed in the second half of the 16th century, during the decades following Paracelsus' death in 1541, and it flourished during the first half of the 17th century, representing one of the most comprehensive alternatives to learned medicine, the traditional system of therapeutics derived from Galenic physiology.

Based on the by then antiquated principle of maintaining harmony between the microcosm and macrocosm, Paracelsianism fell rapidly into decline in the later 17th century with the rise of the scientific movement,^[1] but left its mark on medical practices. It was responsible for the widespread introduction of mineral therapies and several other iatrochemical techniques.

Spagyric, or spagyria, is a method developed by Paracelsus and his followers which was thought to improve the efficacy of existing medicines by separating them into their primordial elements (the tria prima: sulphur, mercury, and salt) and then again recombining them. Paracelsian physicians held that through this method the medically beneficial ingredients of a compound (the purified tria prima) were separated from the harmful and toxic ones, turning even some poisons into medicines.^[2]

This procedure involved fermentation, distillation, and extraction of mineral components from the ash of the plant. These processes were in use in medieval alchemy generally for the separation and purification of metals from ores (see Calcination), and salts from brines and other aqueous solutions.^{[citation needed]}

Originally coined by Paracelsus, the word comes from the Ancient Greek σπάω spao ('to separate, to draw out') and ἀγείρω ageiro ('to combine', 'to recombine', 'to gather').^[3] In its original use, the word spagyric was commonly used synonymously with the word alchemy, however, in more recent times it has often been adopted by alternative medicine theorists and various techniques of holistic medicine.^{[citation needed]}

• Sulfur-mercury theory of metals

• Principe, Lawrence M. (2013). The Secrets of Alchemy. Chicago: The University of Chicago Press. ISBN 978-0226103792.
• Webster, Charles (2013) [1982]. From Paracelsus to Newton: Magic and the Making of Modern Science. Cambridge University Press. ISBN 9780486169132.

• Kühlmann, Wilhelm; Telle, Joachim, eds. (2001). Corpus Paracelsisticum: Dokumente frühneuzeitlicher Naturphilosophie in Deutschland. Band I: Der Frühparacelsismus, Teil 1. Frühe Neuzeit. Vol. 59. Berlin: De Gruyter. doi:10.1515/9783110937855. ISBN 9783110937855.
• Kühlmann, Wilhelm; Telle, Joachim, eds. (2001). Corpus Paracelsisticum: Dokumente frühneuzeitlicher Naturphilosophie in Deutschland. Band II: Der Frühparacelsismus, Teil 2. Frühe Neuzeit. Vol. 89. Berlin: De Gruyter. doi:10.1515/9783110950793. ISBN 9783110950793.
• Kühlmann, Wilhelm; Telle, Joachim, eds. (2001). Corpus Paracelsisticum: Dokumente frühneuzeitlicher Naturphilosophie in Deutschland. Band III: Der Frühparacelsismus, Teil 3. Frühe Neuzeit. Vol. 170. Berlin: De Gruyter. doi:10.1515/9783110296471. ISBN 9783110296471.

• Arber, Agnes (2010) [1912]. Herbals: Their Origin and Evolution. Cambridge University Press. ISBN 978-1-108-01671-1.
• Debus, Allen George (1961). The English Paracelsians: A Study of Iatrochemistry in England to 1640. Harvard University.
• Debus, Allan George (2002) [1991]. The French Paracelsians: The Chemical Challenge to Medical and Scientific Tradition in Early Modern France. Cambridge University Press. ISBN 978-0521894449.
• Kahn, Didier (2007). Alchimie et paracelsisme en France à la fin de la Renaissance (1567-1625). Cahiers d’Humanisme et Renaissance. Vol. 80. Geneva: Droz. ISBN 978-2-600-00688-0.
• Ramos Sánchez, M. C.; Martín Gil, Francisco Javier; Martín Gil, Jesús (1988). "Los espagiristas vallisoletanos de la segunda mitad del siglo XVI y primera mitad del siglo XVII". In Esteban Piñeiro, Mariano; García Tapia, Nicolás; González Arroyo, L.A.; Jalón Calvo, Mauricio; Muñoz Box, Fernando; Vicente Maroto, María Isabel (eds.). Estudios sobre historia de la ciencia y de la técnica: IV Congreso de la Sociedad Española de Historia de las Ciencias y de las Técnicas. Valladolid, 22-27 de septiembre de 1986. Vol. 1. Junta de Castilla y León. pp. 223–228. ISBN 84-505-7145-6.
• Shackelford, Jole (2004). A Philosophical Path for Paracelsian Medicine: The Ideas, Intellectual Context, and Influence of Petrus Severinus (1540/2-1602). University of Chicago Press. ISBN 978-8772898179.