On Leibniz: Expanded Edition

2. Contingentia Mundi: Leibniz on the World’s Contingency

45  2 Contingentia Mundi Leibniz on the World’s Contingency From the earliest days of his philosophizing Leibniz insisted upon the contingency of the world. It was always one of his paramount aims to avert a Spinozistic necessitarianism, and he regarded the contingency of the world’s constituents and processes as an indispensable requisite towards this end, one in whose absence the idea of divine benevolence would be inapplicable. At first thought, it might seem that Leibniz’s teaching that this actual world is only one among many alternative possibilities automatically provides for the contingency needed to escape from necessitarianism. For it might seem that necessity cannot enter in where other alternatives are available . But here appearances might prove deceiving. For Leibniz also wanted to maintain two theses from which the world’s necessity seems to follow as an inexorable consequence; namely, (1) that God, being an omniscient and omnibenevolent creator, is bound to choose the best of possible alternatives for actualization; and (2) that the characteristic design of this actual world of ours makes it the best of possible worlds. On this basis Leibniz is led to confronting the following fundamental argument: I. God actualizes the best possible alternative. II. The possible world answering to description w*—that of our own actual world—is the best of all possible worlds. ∴ God actualizes world w* (our own actual world) 46 Leibniz on the world’S CONTINGENCY Since this argument is to all appearances logically valid, it would appear that if both premisses are necessary, this will also be so with the existence of possible w*, namely, this particular world of ours. A necessitarian position would, of course, be abhorrent to Leibniz, who is ever eager to avoid a Spinozism that excludes contingency from the scheme of things.1 And so one of the central problems of Leibniz’s philosophy is to defeat the charge that his theory that God’s actualization choice of this world is strictly (absolutely, categorically) necessary, with all its unhappy Spinozis­ tic consequences. Clearly, however, avoiding absolute or metaphysical necessity in the conclusion calls for avoiding it in the premisses. Leibniz thus really has no alternative to proceeding by this route. In implementing this approach, Leibniz distinguishes between two different modes of necessity. The one is the meta­ physical necessity of that whose opposite is logico-conceptually impossible. And the other is the moral necessity of that whose opposite is ethically unacceptable . Only the former is absolute and categorical; the latter is standardrelative and dependent upon ultimately evaluative ethical considerations. As Leibniz puts it: But to say that God can only choose what is best, and to infer from thence that what He does not choose is impossible, this, I say, is a confounding of terms: ’tis blending power and will, metaphysical necessity and the moral necessity, essences and existences. For what is [strictly or metaphysically] necessary is so by its essence, since its opposite implies a contradiction. But a contingent which exists owes its existence to the principle of what is best (principle du meilleur), which is a sufficient reason for the existence of things. And therefore I say that [morally necessitating] motives incline without necessitating [metaphysically]; and that there is a certainty and infallibility, but not an absolute necessity in contingent things.2 On this basis Leibniz held that God is necessitated to opt for this world not by his nature (his metaphysical perfection) but by his goodness (his moral perfection).3 Accordingly, Leibniz adopted the principle of a necessitas moralis ad optimum, holding that God’s choice of the best available alternative for actualization, while indeed a certain fact regarding God, is only morally and not metaphysically necessary—and thereby contingent.4 Leibniz on the world’S CONTINGENCY  47 The critical passage at issue (Grua, p. 297) reads as follows: Ex Dei essentia seu summa prefectione certo et, si ita loqui placet, necessara consequentia sequitur Deum eligere optimum; tarnen libere eliget optimum quia in ipso optimo nulla est necessitas absoluta. (From God’s essence or supreme perfection it follows for certain and, so to speak, by consequential necessity [necessitas consequentiae] that God chooses the best. However he chooses the best freely, for in this best there is no absolute necessity.) How is this passage to be understood? For Leibniz, God has two aspects, two dimensions, two natures, to wit, the metaphysical (ontological) and the moral (axiological). His existence, his reality...