Gregory Horstius or Gregor Horst (1578-1636) was a German physician and anatomist at the University of Giessen, founded in 1607. His contemporaries referred to him as the Asclepius of the Germans. Horst was a Galenist. He attempted to unite the hermetic medicine of Paracelsus with the classical Hippocratic medicine. He was, with Andreas Vesalius, a pioneer of modern anatomy.