Paracelsus, full name Philippus Aureolus Theophrastus Bombastus von Hohenheim, was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance.

He was a pioneer in several aspects of the medical revolution of the Renaissance, emphasizing the value of observation in combination with received wisdom. He is credited as the father of toxicology. Paracelsus also had a substantial influence as a prophet or diviner, his Prognostications being studied by Rosicrucians in the 1600s. Paracelsianism is the early modern medical movement inspired by the study of his works.