Paracelsus or Philippus Theophrastus Aureolus Bombastus von Hohenheim, a.k.a. this guy:

© Musée du Louvre

Was born in Switzerland in 1493 and had his doctorate in medicine by 1516 at the University of Ferrara. He is one of the major founders and practitioners of medicinal chemistry, alchemy, and the basis of modern toxicology, challenging the mindset of the scholars at the time.

Travelling Europe and the Middle East, he became a physician/surgeon and contemplated human existence in relation to the universe. He then advocated for the rejection of conventional medical practices taught at universities, appealing to the medical community that the whole system of teaching should be reformed. As an alchemist, Paracelsus applied chemistry to medicine in accordance with the human body, which he saw as a functioning chemical system both internally and with its environment. He was deeply concerned with life, death, the body, the soul, and the human relationship with nature and God.