Medicine and health care were perhaps the highest scientific achievement of the Muslims during the Middle Ages. The author discusses the history of rainbow and attempts to provide a historical and scientific explanation for the rainbow phenomenon according to Muslim scientists generally and Hocazade especially. Marifetname deals with classical scientific subjects such as mathematics, astronomy, medicine and physics. It also offers discussions on modern scientific concepts and presents certain contradictory statements on Islamic sciences. Dr Ziaee also discuses the quality of representing the human values like freedom, liberality, tolerance, faith, certainty, and etc in the form of semantics. In the last chapter he criticizes Nasir Khusraw''s definition of the first intellect and then describes his position of ?ibda'' or innovation. Ziaee tries to debate Nasir Khusraw''s relevant philosophical issues and contradictions in his works respect to these narrow field of study.