This source then becomes the more basic principle, logically prior to either Ormuzd or Ahriman. This corrected the logical flaw introduced when Ahura Mazda was reduced to the level of Angra Mainyu as a result of his identification with Spenta Mainyu. This point was stressed most firmly by the Mazdakians who insisted that the actions of evil were not directed, but random. I find this insight particularly instructive in understanding what is known in the philosophical community as natural evil . This term refers to bad things that happen that cannot be reasonably explained as a result of human misbehavior.
Examples are misfortunes such as birth defects, epidemics, and natural disasters such as tornadoes.
Such things are responsible for great human suffering. Unlike human evil, this evil acts blindly. One is in the wrong place at the wrong time and suffers. Some insight can be gained by considering the case of a tornado. Suppose I were to show you a movie of a tornado bearing down upon a building and reducing it to rubble.