The Source of the Faculties is the Soul: Pre-modern Islamic Medicine and its Relation to Philosophy and Religion


20 Feb 2013

History of Science, Medicine

Nahyan Fancy

Nahyan Fancy, associate professor of History at DePauw University (Indiana) lectures in this video on how the concepts of spirit and soul (rūḥ and nafs respectively, in his use) were integrated into both medical understandings of the body and its physiology, and conceptualizations of how resurrection might occur, given those understandings of physiology.

Fancy works through the basic medical constructions of Aristotle (d. 322 BCE), Galen (d. ca. 210), and Ibn Sina (d. 1037) before addressing the thinker in whom he is most interested, Ibn al-Nafis (d. 1288, Cairo).  For these earlier thinkers, the soul is immaterial, but gives the body the capacity to move, and it is connected with the heart.  By the time of Galen, veins and nerves had been identified, and it was understood that movement is connected with the nerves and the brain, so ideas about the soul have to become more integrated into the whole bodily system.  Ibn Sina sought to resolve the brain/heart problem, and seems to have done it through connecting (via rational proofs) the soul to individual resurrection.  For Ibn Sina, the soul comes into existence at the same time with the body, but it needs to remain individuated in order to survive the disintegration of the body.  Ibn Sina did not have a clear resolution to the problem of individuation.

Ibn al-Nafis, Fancy notes, wanted to show there was a way to understand and defend bodily resurrection on a scientific footing.  He solved the problem by examining the point of embryogenesis, and noting the combination of the two semens (the man’s and the woman’s, as it was then understood) created the soul, and this balanced mixture was the individuated element to which the soul was connected.  This was contrasted with more Ṣūfī-like understandings of Ibn Tufayl (d. 1185) at the time, in which the soul was thought to be part of a Divine emanation.

The lecture was presented on October 20, 2012 at the Insight Institute of Neurosurgery & Neuroscience (IINN) in Flint, Michigan, as part of a conference entitled The Self and Soul in Islamic Thought.  YouTube has a playlist of the videos from the conference here.


The material on Islam is within the bounds of what Muslims have historically understood as acceptable.

The science presented accurately represents the development of the ideas through history.  The interconnections of science and Islam during the periods examined here is close, but the reliance on reasoning and experimentation is also evident.

The historical material presented reflects consensus academic views.