ובמשנת הרמ"ד בנוגע דעם פראבלעם פון גיהנום ועונש לנצח (ומכח ווייל מען האט פוגם געווען קעגן איינער וואס איז נצחי), שרייבט דר. מיכה גאטליב אודות המחלוקת בזה בין הרמ"ד ובין לייבניץ:
Leibniz claims that the principle of sufficient reason demands a reason for the existence of this world as a totality. Leibniz locates this reason in God’s goodness, which led God to choose to create this world as the best of all possible worlds. For Leibniz, this is perfectly compatible with events in the world being explicable according to natural causes, for in creating this world God ordains a harmony between efficient and final causes
But while Leibniz is correct in stressing God’s goodness as the preeminent expression of His power, Mendelssohn claims that Leibniz does not fully appreciate this point on account of his commitment to Christian dogma. As a Christian, Leibniz feels bound to justify the doctrine of eternal punishment. This doctrine, however, appears to be irreconcilable with God’s goodness for according to traditional Christian teaching, the vast majority of humankind are doomed to eternal suffering. To resolve this problem, Leibniz offers several possible solutions. First, Leibniz writes that while God’s goodness seeks the greatest perfection, perfection is not just a function of human happiness, but is also a function of the beauty and order of the universe. This beauty and order includes the moral order of the universe, which demands “satisfaction for the expiation of an evil action.” Certain sins are so grave, however, that they demand eternal punishment. In such cases, punishment “gives satisfaction . . . to the wise who see it; even as a beautiful piece of music, or again a good piece of architecture, satisfies cultivated minds.” Lloyd Strickland calls this the doctrine of “abominable fancy.” Second, Leibniz interprets God’s goodness as requiring that God choose the best possible universe, not a perfect universe without suffering, which is impossible. The relative goodness of the universe is a function of the ratio between the number of beings who suffer and the number who enjoy blessedness. Leibniz proposes that while on earth the majority of people are destined to suffer eternally, there may be countless inhabitants of other planets who enjoy eternal beatitude. Hence despite the fact that most of humanity will suffer eternally, the amount of suffering in our universe may be relatively small
For Mendelssohn, Judaism’s fundamental insight is that God’s goodness involves God’s concern for the happiness and perfection of every individual. While Leibniz labels this view “a remnant of the old and somewhat discredited maxim, that all is made solely for man,” Mendelssohn upholds this “discredited maxim” in an extreme way claiming that God’s goodness implies that God treats every individual human being as an end in themselves of infinite value whose happiness and perfection can never be sacrificed for the of benefit others. For Mendelssohn, the only purpose of suffering is corrective, namely as a spur to the individual’s own improvement, hence God will only let an individual suffer as long as it helps her improve. To this end, Mendelssohn cites the medieval Bible commentator Ibn Ezra (Exodus 34:7) who notes that punishment itself is also “a quality of God’s infinite love.” Eternal punishment is unacceptable as a person suffering eternally cannot reach a higher level of perfection. For perfection involves happiness, which requires the cessation of suffering
Mendelssohn harshly criticizes Leibniz’s various attempts to defend eternal punishment. Mendelssohn’s view that God deems the happiness of every individual an end in itself leads him to reject Leibniz’s doctrine that a wicked person could be made to suffer for the enjoyment of the righteous. For Mendelssohn, Leibniz’s claim that there exist infinite numbers of other beings whose blessedness outweighs the suffering of the majority of mankind is a deus ex machina dreamed up in order to defend a Christian theological dogma that contains “insoluble difficulties.” Similarly, the notion that certain very grave sins merit eternal punishment is incoherent. For Mendelssohn, eternal punishment could only be appropriate where sin is infinite. Sin can be infinite in two ways either in terms of its quantity, that is, the number of sins committed, or in terms of quality, that is, the degree of honor of the offended party. Given that human beings are finite, the number of their sins can only be finite, and since God is perfectly self-sufficient, His honor can never be offended by human sin. God’s being offended by human actions is as ridiculous as a mother feeling affronted because her baby bites her breast while seeking nourishment. God needs nothing from us — His purpose in creating the world is to promote human happiness and perfection