Theodicy: In Christian theology,any attempt to reconcile the occurrence of evil and/or suffering in the world with the traditional theistic attributes of omnibenevolence (i.e."all-loving"), omniscience (i.e. "all-knowledge"), and omnipotence (i.e. "all-power").The theodicy conundrum is typically set up as a "best possible worlds" dilemma: of all possible worlds that could have been created, why would an all-loving, all-knowing, and all-powerful God create a world in which evil and suffering exist? Why did God create the circumstances that would allow Adam to sin? These questions, the stuff of anti-theist rejoinders, have been the perennial bane of Christian theology for time immemorial.
In his Essays on the Goodness of God, the Freedom of Man and the Origin of Evil, the German mathematician and philosopher, Gottfried Leibniz (1646-1716), proposed a rather ingenious solution to the best possible worlds dilemma. Leibniz agreed that a world created by an all-loving, all-knowing, and all-powerful God would necessarily have to be the best of all possible worlds, and so he believed the world to be! His ingenuity was seen in his novel solution to the problem of evil. The presence of evil and suffering in the world, so he argued, was necessary for the realization of the highest possible good. In other words, God was an "optimizer" of sorts, allowing evil in order to optimize the degree of goodness manifested in the world. A world devoid of evil, while perhaps paradisaical, could never know the higher virtues characteristic of a world in which evil existed -- virtues such as fidelity, sacrifice, bravery, courage, altruism and the like. These can only be known in a world like ours, that is, the best of all possible worlds. Leibniz not only believed that his solution resolved the theodicy conundrum, he also saw it as the best proof for Christian theism.
Naturally, Leibniz's solution produced many critics. The celebrated atheist, Voltaire, would opine that the amount of suffering actually seen in the world could in no way justify Leibniz's optimism. Voltaire's retort had the force of the preponderance of human experience behind it, at least for those who did not turn a blind eye towards the ravages of poverty, war and disease. Yet little did Voltaire know in his day that such societal evils were merely the tip of the iceberg. Modern science, particularly the insights of evolutionary theory, would go on to reveal a world where the formation and exhaustion of stars, the energy demands of biological life forms, tooth-and-claw competition, suffering, pain, death, biological dead-ends, mass extinctions and the like not only existed, but were in fact the rule: the metanarrative of "the world of the universe that is." In fact, the "higher virtues" of Leibniz's best possible world would not emerge until eons and eons of senseless, ravenous and cannibalistic processes had finally produced -- in a tiny, unremarkable recess of the universe -- moral creatures such as ourselves. Relatively speaking, such virtues appear to be a meaningless aberration in a world defined by "death"; illusions born of evolutionary adaptations that our species happened to find useful in the competition of the survival of the fittest.
Voltaire's retort certainly had subjective and emotive force behind it, but it would still be possible to argue that the "highest possible good" was ultimately a valuation judgment best left to God, the judge of all things. Indeed, the real weakness of Leibniz's solution was not his "optimizing of the good" explanation for the existence of evil, but rather the implicit determinism that the "best possible worlds" dilemma assumes from the outset. If, as the dilemma contends, an all-loving, all-knowing, and all-powerful God must create a world in which the most optimal conditions exist for the realization of the highest possible good, then all future reality must in some sense already exist in the mind of God. Simply put, from eternity past, God would have had to will the creation of a world in which he infallibly knew all that would take place, and could not have chosen to create any other!
Leibniz was not the first to fall unwittingly into the trap of determinism. Christian theology had been entangled in determinism since the days of Origen. Indeed, even today most Christians are little aware of how pervasive determinism is and how it affects their theistic beliefs, often in self-contradictory ways. This is particularly the case with the traditional understandings of omnibenevolence, omniscience, and omnipotence. A God who is bound by his "all-loving" character to create the "best possible world" can hardly be said to be "all-powerful." The very concept of "best possible" becomes nonsensical, since, in the infallible foreknowledge of God, only one possibility exists!
Determinism has created more problems than necessary, particularly in the perennial preoccupation of Christian theologians to absolve God as the cause of evil and suffering. This is typically done by distinguishing between the "two wills" of God, namely, the causative and the permissive. So it is argued that to permit evil is not the same thing as causing it; hence, God cannot be said to be the author of evil if he merely permits it to exist (its causation being attributed to other moral agents, like fallen angels and Adam).
However, the knowledge of future actions and the decree to create in view of them amounts to the same net result: soft determinism is still determinism. Even if (in good Molinist fashion) the free agency of moral beings is built into the system to account for the causation of evil (i.e. sin, suffering, etc.), this could only be admitted as a means towards a divinely appointed end. In actuality, free agency would simply not exist in such a world; only the appearance of it. One may choose chocolate over vanilla, but if that choice were determined ahead of time (insofar as God chose to create a world in which all future actions were infallibly foreknown), then no other choice would ever be possible. In another scenario, one could just as well "choose" to commit murder, and that choice would be just as certain from an eternal standpoint. In the final analysis, it is impossible to exonerate God entirely from evil in any deterministic system.