Paracelsus

Who they were

Theophrastus Bombastus von Hohenheim (1493–1541), who called himself Paracelsus — beyond Celsus, the Roman medical authority — was a Swiss physician, alchemist and reformer who did more than anyone to turn alchemy toward medicine, and who managed to be both a founder of modern pharmacology and a principal source of Renaissance occultism.

Where they came from

Born near Einsiedeln in Switzerland, son of a physician. He travelled constantly — through the German lands, Italy, France, possibly further east — working as an army surgeon and learning, by his own account, more from barbers, midwives, bath-attendants and miners than from universities.

That is the key to him. He held that medical knowledge came from experience and from nature, not from authorities, and he despised the Galenic academic medicine of his day with an energy that cost him every position he obtained.

In 1527 he was appointed town physician and lecturer at Basel, and within a year had destroyed his own career. He lectured in German rather than Latin, admitting barber-surgeons to his classes. He publicly burned the works of Galen and Avicenna in a bonfire on Saint John's Day. He described his colleagues in terms that do not translate politely. He was gone within twelve months and spent the rest of his life wandering.

He died at Salzburg at forty-seven.

What they taught

Iatrochemistry — chemical medicine. Where Galenic practice worked with herbal preparations and the balancing of humours, Paracelsus argued that specific diseases had specific causes and required specific chemical remedies, prepared by alchemical means. This is the beginning of pharmacology as a discipline of preparing and dosing active substances.

He introduced laudanum, the tincture of opium, into European practice; used mercury compounds for syphilis; and named and worked with zinc.

The dose principle, and this alone would secure his place:

All things are poison and nothing is without poison; the dose alone makes a thing not poison.

That is the foundation of toxicology, stated in the sixteenth century, and it remains exactly correct. It also demolishes, four hundred years early, the "natural means safe" assumption addressed under traditional herbalism.

Occupational medicine. On the Miners' Sickness is the first systematic study of a disease caused by an occupation, examining the lung conditions of metal miners and their causes. It founded a field.

The tria prima — salt, sulphur and mercury as the three principles underlying all substances, replacing the four elements as an explanatory scheme for chemical behaviour.

And the occult inheritance. He was a committed proponent of the doctrine of signatures, which he systematised. He taught the archeus, an inner alchemist governing the body's transformations. And he supplied the names for the elemental beings that Western esotericism has used ever since — gnomes of earth, undines of water, sylphs of air and salamanders of fire. That entire vocabulary is his coinage.

What we can and cannot say

We can say the medical contributions are real, substantial and permanent. The dose principle, chemical therapeutics and occupational medicine are not marginal achievements.

We can say the framework producing them was not one modern medicine would recognise. He worked within a cosmos of correspondences, signatures, astral influences and elemental spirits, and in his own understanding the chemistry and the magic were not separable — the same principle that runs through alchemy generally, and the reason sorting his work into "the good scientific part" and "the superstitious part" is an anachronism, however tempting.

We can say a great deal of what he specifically believed was wrong, including the signatures, and that mercury for syphilis probably killed a substantial number of the people it was given to.

We can say he was difficult in ways that are not romantic. He was abrasive to the point of self-destruction, frequently drunk by contemporary account, and his writings contain antisemitic passages of the kind common in his period and not excused by it. The image of the heroic free-thinking outsider is partly his own construction and partly true, and he was also a man almost nobody could work with.

We cannot say how much of the corpus attributed to him is his; a great deal of Paracelsian literature was written by followers and published under his name after his death, which is a recurring problem in this section.

Further reading

• Paracelsus, Essential Writings, ed. Jolande Jacobi — a manageable selection.
• Charles Webster, Paracelsus: Medicine, Magic and Mission at the End of Time (2008) — the standard modern study.