On Augustine's weak understanding of Evil

Augustine . . .  Under Neoplatonic influence . . . taught that all existing things are good; evil, therefore, does not exist - it is metaphysically unreal. Being non-existent, it can have no cause, and God therefore is not the cause of evil. When a man sins, it is a case of his choosing a lower good instead of a higher good. This choice too has no efficient cause, although Augustine assigns to it a deficient cause. In this way God was supposed to be absolved. Augustine, admittedly, was a great Christian and a great philosopher. Later in the chapter more will be said about him. But here he was at his worst. Deficient causes, if there are such things, do not explain why a good God does not abolish sin and guarantee that men always choose the highest goods.

This is an interesting quote by Gordon H. Clark. The last sentence seems to say that even if God is void of the cause of sin and evil it still does not give us any real reason why sin and evil are not totally destroyed or absolved. Herman Hoeksema in his Reformed Dogmatics says something of this - for God to be able to stop or prevent evil but does not, would make Him just as responsible.