Albert's Refutation of the Extramission Theory of Vision and His Defence of the Intromission Theory: English Translation and Analysis of His Muslim Sources

All natural philosophers had struggled to comprehend and explain how we see objects until Johannes Kepler devised his new theory of the retinal image early in the seventeenth century. In antiquity, Empedocles, Plato, Galen, Euclid and Ptolemy defended the extramission theory of vision, according to which the eye issues radiation to feel and perceive opaque objects, whereas Aristotle expounded the intromission theory of vision, according to which radiation is sent to the observer's eye from without. In Islam, Ibn Sina established the Aristotelian intromission theory as a viable alternative. He effectively argued that light is transmitted from the visual object to the eye, putting forward original and convincing arguments against the extramission theory. Ibn al-Haytham and Ibn Rushd also defended the intromission theory. In the West, Albert the Great followed the arguments of Ibn Sina closely, especially in his book De sensu et sensato, and thus became Ibn Sina's principal disciple and expositor in refuting the extramission theory of vision. Albert not only brought the Western optical theory to the same level it had achieved in Islam in the writings of Ibn Sina and Ibn Rushd, but also played a crucial role in the acquisition and assimilation of the optical works of Greek and Muslim authors (with the exception of Ibn al-Haytham's technical work, De aspectibus). This book examines Albert the Great's treatment of visual theory in his De sensu et sensato, ostensibly a commentary on Aristotle's treatise of the same title, and analyses his Muslim sources. It contains a new critical edition and translation of the Chapters 3 to 14 of De sensu et sensato, along with variant readings, explanatory notes and introduction. Since Albert borrowed ideas from Muslim philosophers and acknowledged his debt to them by citing their names, this study sheds some light on the interaction between Islamic and Western civilization.

Table of Contents:
Introduction A Biographical Sketch of Albert the Great Muslim Sources of Albert's Contribution to Optics Editorial Procedures Manuscripts and Printed Editions Critical Text and English Translation: Some Portions of De Sensu Notes and Commentary Variant Readings Bibliography

About the Author :
Cemil Akdogan received his Ph.D. from the University of Wisconsin. He taught at the Middle East Technical University in Ankara before becoming a Professor at the International Institute of Islamic Thought and Civilization (ISTAC) in Kuala Lumpur, Malaysia.