ابن النفيس
What distinguish the book most is the confident language which Ibn al-Nafis shows throughout the text and his boldness to challenge the most established medical authorities of the time like Galen and Avicenna. Ibn al-Nafis, thus, was one of the few medieval physicians—if not the only one—who contributed noticeably to the science of physiology and tried to push it beyond the hatch of the Greco-Roman tradition.