Albertus Magnus (1193-1280) was also the teacher of St. Thomas Aquinas. He is often praised for his rejection of dogmatic philosophy and his stress on experimentation. Many books, including the Little Book on Alchemy, were falsely attributed to Magnus but likely written by Paracelsus.

Paracelsus (1200-1280) was a medieval Swiss theologian and physician interested in alchemy and astrology, and a pioneer in the medical revolution of the German Renaissance. Albertus Magnus (1193-1280) was a German Catholic Dominican friar and bishop. Known as Albert the Great or later Saint Albert, Magnus also wrote on alchemy and was the first to comment on the writings of Aristotle and the teachings of Muslim academics, notably Avicenna and Averroes.