The practical solution oftenest adopted has been that which sacrifices the Creator's omnipotence in favour of his benevolence. In the noblest of the purely Aryan religions--that of which the sacred literature is contained in the Zendavesta--the evil spirit Ahriman exists independently of the will of the good Ormuzd, and is accountable for all the sin in the world, but in the fullness of time he is to be bound in chains and shorn of his power for mischief.[19] This theory has passed into Christendom in the form of Manichæism; but its essential features have been adopted by orthodox Christianity, which at the same time has tried to grasp the other horn of the dilemma and save the omnipotence of the Deity by paying him what Mr. Mill calls the doubtful compliment of making him the creator of the devil. By this device the essential polytheism of the conception is thinly veiled. The confusion of thought has been persistently blinked by the popular mind; but among the profoundest thinkers of the Aryan race there have been two who have explicitly adopted the solution which limits the Creator's power. One of these was Plato, who held that God's perfect goodness has been partially thwarted by the intractableness of the materials he has had to work with. This theory was carried to extremes by those Gnostics who believed that God's work consisted in redeeming a world originally created by the devil, and in orthodox Christianity it gave rise to the Augustinian doctrine of total depravity, and the "philosophy of the plan of salvation" founded thereon. The other great thinker who adopted a similar solution was Leibnitz. In his famous theory of optimism the world is by no means represented as perfect; it is only the best of all possible worlds, the best the Creator could make out of the materials at hand. In recent times Mr. Mill shows a marked preference for this view, and one of the foremost religious teachers now living, Dr. Martineau, falls into a parallel line of thinking in his suggestion that the primary qualities of matter constitute a "datum objective to God," who, "in shaping the orbits out of immensity, and determining seasons out of eternity, could but follow the laws of curvature, measure, and proportion."[20]