<P> Aelius Galenus or Claudius Galenus ( / ɡəˈliːnəs / ; Greek : Κλαύδιος Γαληνός ; September 129 AD -- c. 200 / c. 216 ) , often Anglicized as Galen and better known as Galen of Pergamon ( / ˈɡeɪlən / ) , was a prominent Greek physician , surgeon and philosopher in the Roman Empire . Arguably the most accomplished of all medical researchers of antiquity , Galen influenced the development of various scientific disciplines , including anatomy , physiology , pathology , pharmacology , and neurology , as well as philosophy and logic . </P>
who is considered to be the most influential writer of all time on medical subjects
Aelius Galenus or Claudius Galenus