Paracelsus (/ˌpærəˈsɛlsəs/; German: [paʁaˈtsɛlzʊs]; c. 1493^[1] – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim^[11][12]), was a Swiss^[13] physician, alchemist, lay theologian, and philosopher of the German Renaissance.^[14][15]

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".^[16] Paracelsus also had a substantial influence as a prophet or diviner, his "Prognostications" being studied by Rosicrucians in the 17th century. Paracelsianism is the early modern medical movement inspired by the study of his works.^[17]