Galen was a Greek who became the Ancient Roman Empire’s greatest physician. He had great expertise in anatomy, surgery, pharmacology and therapeutic methods.
Galen had an absolute belief in the power of experiment and observation. He did not believe in merely following what books told him was true. He needed to verify the truth for himself.
His anatomical reports, based mainly on dissection of monokeys, remained uncontested until 1543, when printed descriptions and illustrations of human dissections were published.
Galen, the great scientist, consolidated the work of previous Greek medical researchers, adding the results of his own research, to create an incredibly long-lasting medical doctrine. This medical doctrine dominated the Western world for 1500 years.