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Paracelsus: the Father of Toxicology and the Enemy of Physicians


Toxicology is a branch of knowledge dealing with the scientific study of the characteristics and effects of poisons on living organisms. The man considered to be the ‘father’ of this discipline is Philippus Aureolus Theophrastus Bombastus von Hohenheim, also known as Paracelsus. It is said that Paracelsus meant ‘equal to Celsus’ (referring to the Roman encyclopaedist Aulus Cornelius Celsus), and the change in his name was meant to be an indication of Paracelsus’ desire to rival ancient medical authorities such as Celsus and Galen.

Following in His Father’s Footsteps

Paracelsus was born in 1493 in Einsiedeln, Schwyz, the Old Swiss Confederacy (modern day Switzerland). Paracelsus’ father, Wilhelm Bombast von Hohenheim, was a Swabian nobleman said to have been born out of wedlock in an impoverished family of knights. Wilhelm was himself a physician, and was mentioned by Paracelsus to be one of his earliest teachers. When Paracelsus’ mother, Els Ochsner, died when he was just nine years old, the father and son moved to Villach in Carinthia. By watching his father giving medical comfort and aid to visiting pilgrims, the young Paracelsus developed a desire to emulate his father. Wilhelm also nurtured Paracelsus’ growing interest by teaching him the basics of medicine. Furthermore, Wilhelm gave his son herbs and stones, water and metals, as friends, thus initiating him into the wonders of nature.

Conflicting Stories on Paracelsus’ Further Learning

Apart from his father, Paracelsus was also taught by several bishops, including Eberhard Paumgarthner, the bishop of Lavant, and Matthæus Schacht, the bishop of Freising. In addition, Paracelsus studied alchemy under the occultist abbot of Sponheim, Johannes Trithemius. At the age of 16, he began studying medicine at the University of Basel in Switzerland. According to one source, it was at Basel that Paracelsus met and studied under the guidance of a wealthy physician, Sigismund Fugger. In 1516, however, Paracelsus was forced to leave the city hurriedly, as he ran into some problems with the authorities for his studies in necromancy. According to another source, Fugger’s laboratory was located in Schwaz, Austria, rather than in Basel. Yet another source suggests that there was no proof that Paracelsus even took a degree in medicine.

A copy of Quentin Matsys’ portrait of Paracelsus.

A copy of Quentin Matsys’ portrait of Paracelsus. (Wikimedia Commons)

The Many Travels of Paracelsus

The sources agree, nevertheless, that Paracelsus spent a long period of time wandering abroad. Paracelsus’ travels took him to such countries as Germany, France, Hungary, the Netherlands, Denmark, Sweden, and Russia. One source claims that whilst in Russia, Paracelsus was captured by the Tatars, and brought to the court of the Grand Cham. He became a court favorite, and even accompanied the Cham’s son on a diplomatic mission to Constantinople. It is further claimed by this source that in Constantinople, an Arab adept imparted the secret of the universal solvent (the alkahest) to Paracelsus. It is also said that Paracelsus attended many of the most important European universities during his travels, and gained practical medical knowledge whilst serving as a surgeon in the camps of various mercenary armies.

Fortunately for us, the records of Paracelsus’ travels become clearer for the last 15 years of his life. In 1526, Paracelsus arrived in Strasburg, where he joined a guild of surgeons. In the same year, he returned to Basel to treat a leg ailment of Johannes Frobenius, a famed publisher. It has been suggested that thanks to Frobenius’ influence, Paracelsus was appointed to the office of the city physician of Basel, which entitled him to lecture at the city’s university.

The Luther of the Physicians

It was his actions during this time that perhaps later earned Paracelsus the nickname ‘the Luther of Physicians’. Among his ‘heretical’ actions were his opposition to the revered Galeno-Arabic system, the burning of Avicenna’s writings in a public square, and his attack on the greed of apothecaries. Those in authority came to hate him, and Paracelsus was soon expelled from the city (again.) Paracelsus began to wander around Europe yet another time, and eventually died in Salzburg in 1541.  

Woodcut of Paracelsus by Tobias Stimmer (1541)

Woodcut of Paracelsus by Tobias Stimmer (1541) (Wikimedia Commons)

Paracelsus’ contributions to Medicine

One of Paracelsus’ contributions to the field of medicine was the idea that pathological changes were caused not only by internal factors, i.e. the four humors, but also by external factors. These included ‘cosmic influences differing with climate and country, as well as ‘toxic matter originating in food’.

Additionally, Paracelsus proposed that all natural substances have two types of influences –a helpful one, and a harmful one, which were separated by means of alchemy. This led to one of Paracelsus’ most famous adages, which is also the fundamental principle of classical toxicology, “Alle Dinge sind Gift und nichts ist ohne Gift, allein die Dosis macht es, dass ein Ding kein Gift ist.” meaning “All things are poison and nothing is without poison; only the dose makes a thing not a poison.” This has often been shortened to “The dose makes the poison.”

Featured image: A copy of Quentin Matsys’ portrait of Paracelsus (flickr)

By Ḏḥwty


Cockren, A., 1941. Paracelsus. [Online]
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Paracelsus; Jacobi, J. (ed.) 1995. Paracelsus, Selected Writings. Princeton: Princeton University Press.

Senfelder, L., 1911. Theophrastus Paracelsus. [Online]
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U.S. National Library of Medicine, 2011. Paracelsus. [Online]
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It’s a given that susceptibility is a factor.  How does that make what I said half true?

Half true; the other half is the susceptibility of an organism to the poison.

“The dose makes the poison.”

This complete load of crap is an ideological cornerstone of the modern medical and food industries, and it's part of the reason both are killing so many people.  Some substances are innately poisonous (toxic), while others are only harmful when taken in an amount which overwhelms the body.  Promoting the idea that there is no difference has made a few people a lot of money, and many more sick.

dhwty's picture


Wu Mingren (‘Dhwty’) has a Bachelor of Arts in Ancient History and Archaeology. Although his primary interest is in the ancient civilizations of the Near East, he is also interested in other geographical regions, as well as other time periods.... Read More

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