Paracelsus (1493-1541), born Theophrastus Philippus Aureolus Bombastus von Hohenheim, was a Swiss physician, alchemist, and philosopher. He revolutionized medicine in his time by rejecting the theories of Galen and Avicenna and promoting the use of chemicals and minerals in treatments. He traveled throughout Europe in search of knowledge, studying with healers and scientists. An advocate of medical astrology, he believed in the connection between the macrocosm and the microcosm. His writings cover alchemy, medicine, and prophecies. He was a controversial figure, criticized by his contemporaries, but influential in the evolution of medical science. He died in Salzburg in 1541.