Paracelsus (1493 - 1541) was a famous alchemist, physician and occultist. Born Theophrastus Bombastus von Hohenheim, he took the name Paracelsus later in life, meaning "superior to Celsus", an early Roman physician. He was also known by the pseudonym Theophrastus Philippus Aureolus Bombastus von Hohenheim.

Paracelsus was born at Einsiedeln, Switzerland, of a Swabian chemist father and a Swiss mother. He was brought up in Austria and as a youth he worked in nearby mines as an analyst. He graduated with a baccalaureate in medicine from the University of Vienna in 1510, at the age of 17. There is speculation he gained his doctorate degree from the University of Ferrara.

He later journeyed to Egypt, Arabia, the Holy Land, and Constantinople seeking the alchemists to learn from. On his return to Europe his knowledge of these treatments won him fame. He did not go along with the conventional treatment of wounds, which was to pour boiling oil onto them to cauterize them; or if they were on a limb, to let them become gangrenous, and then amputate the limb. Paracelsus believed the then-ridiculous assumption that wounds would heal themselves if allowed to drain and prevented from becoming infected.

Paracelsus rejected Gnostic traditions, but kept much of the Hermetic, neoplatonic, and Pythagorean philosophies; however, Hermetical science had so much Aristotelian theory that his rejection of Gnosticism was practically meaningless. In particular, Paracelsus rejected the magic theories of Agrippa and Flamel; Paracelsus did not think of himself as a magician and scorned those who did.

Paracelsus pioneered the use of chemicals and minerals in medicine. He coined the words "alcohol" and "zinc" and used experimentation in learning about the human body. His hermetical views were that sickness and health in the body relied on the harmony of man the microcosm and Nature the macrocosm. He took an approach different from those before him, using this analogy not in the manner of soul-purification but in the manner that humans must have certain balances of minerals in their bodies, and that certain illnesses of the body had chemical remedies that could cure them. (Debus & Multhauf, p.6-12) He summarized his own views: "Many have said of Alchemy, that it is for the making of gold and silver. For me such is not the aim, but to consider only what virtue and power may lie in medicines." (Edwardes, p.47)

Indeed, the remnants of alchemical traditions can still be seen in modern medicine. For instance, the Caduceus (the staff of Hermes), has been adopted as the prime symbol of western medicine.

Paracelsus gained a reputation for being arrogant, and soon garnered the anger of other physicians in Europe. He held the chair of medicine at the University of Basel for less than a year, while there he angered his colleagues by burning books by other physicians. He was forced from the city after having legal trouble over a physician's fee he sued to collect.

He then wandered Europe for some time, typically as a pauper. He revised old manuscripts and wrote new ones, but had trouble finding publishers. In 1536 his Die grosse Wundartzney (The Great Surgery Book) was published which enabled him to make a short comeback in popularity.

Paracelsus is the title of a 1943 film by Georg Wilhelm Pabst.