In article one of the challenges in the history of philosophy and divinity — a problem of occurrence and evil existence is investigated. On a considerable quantity example Slavic medieval texts it is shown, how the problem of occurrence of evil in the world dared. The great attention is given Palee Sensible and a legend about falling of Satanail thanks to which representations of our Ancient Russian ancestors about the evil nature were formed. In conformity with tradition Ancient Russian scribes interpreted evil as «non-existence» which did not enter into a plan of the Creator about the world. On concrete texts it is shown that angrily it is not involved in an order of things that it not independent ontologic essence, and result of distortion of life and the spiritual conditions of people connected with it. Malicious and the sin which has come with it in monuments of Ancient Russian writing are considered as «illness» of free will which owing to a human nature is inclined to accept its phantom for good. Are reconstructed based on bible postulates dogma installations according to which evil is considered as a reality only in consequences strong-willed actions of the created subjects which contrary to a divine plan and give existence to evil in the world.