Pp. xxv, 322 , New Haven and London , Yale University Press , 2007 , $60.00.
A frequent motif running through Nietzsche's late writings is his dismissal of the classical German philosophers, Leibniz, Kant, and Hegel, as theologians. In the Anti-Christ, he remarks that in the veins of these philosophers ‘ran theologians' blood.’ It is not the least of the many accomplishments of the book under review about Leibniz's theological interests that the author successfully upholds Nietzsche's judgment without, however, reducing Leibniz's philosophical projects to theological addenda: Leibniz's blood was coherently philosophical and theological at the same time. In this superbly researched and extensively documented work, Maria Rosa Antognazza promotes a heretofore side issue in Leibnizian scholarship, namely his conceptual analysis and defense of the doctrines of the Trinity and the Incarnation, to a pivotal role in the development and articulation of his broader metaphysical views. Combining impressive analytic clarity with comprehensive historical reach, she exams chronologically Leibniz's widely scattered and fragmented texts on theology and convincingly argues both for their internal consistency and coherence with his mature metaphysical system. The result is an enlightening and refreshing piece of scholarship that will put to rest once and for all any temptation to think of Leibniz as a rational deist at the expense of Leibniz the philosophical theist.
Leibniz's lifelong debate with the antitrinitarian Socinian sect constitutes the focus of her argument. The Socinians maintained that the Christian belief in the Trinity was irrational, and therefore unworthy of belief, because its claim of divine simplicity (unity) existing alongside the real distinctions of persons (multiplicity) was evidently self-contradictory. Their assumption was that human reason, anchored in the principle of non-contradiction, could pass judgment on the truth claims of Christian revelation. Leibniz's argument in defense of revelation first establishes the conformity between faith and reason, and then elucidates reason's role in explicating the meaning of the mysteries as well as the process of coming to belief. He disarms the Socinian premise by distinguishing truths beyond reason from ‘truths’ that are contrary to reason. Theological propositions that contradict reason violate the necessary harmony of God with the universe and consequently are to be rejected. If this claim is unassailable, then Leibniz need only show how human reason continues to play a central role in clarifying those revealed mysteries that not only exceed its capacity to understand, but seem prima facie also to contradict it.
Leibniz proceeds by means of an astonishingly simple reversal of the traditional theistic approach: since reason cannot demonstrate either the triune nature of God or the Incarnation, it is sufficient for belief to show that these mysteries are possible (although improbable in light of common experience) insofar as they can be thought without contradiction. Thus the onus of proof falls on the opponents of the doctrines to demonstrate how contradictoriness is present. The second step in reason's defence of revealed truth involves the intelligibility of the act of belief: Leibniz postulates that to believe something is to ‘hold something as true’ (‘verum putare’), but to hold as true entails some understanding of the meaning of the words in use. One cannot hold meaningless sounds (‘sine mente soni’) as true. Leibniz carefully displays and explicates the meaning of these truths by an appeal to the Scholastic notion of analogy, which provides ‘confused knowledge’ of the supernatural truths sufficient for belief. Leibniz analyzes the functions and relations of the human mind, its power, knowledge, and will to illustrate how the unity of a being is not compromised by its distinct functions – unity can in fact be constituted by real relations.
But a further question, perhaps the most crucial regarding Leibniz's ambitious project, needs to be raised: why should a rational person actually hold such claims as true? Surely establishing the Trinity and Incarnation as logically possible, the terms of which are to a certain degree intelligible to us, does not compel belief. Unfortunately, Antognazza spends considerably less time on what Leibniz calls the ‘motives of credibility,’ than on the prior steps of the argument. Leibniz never swayed from his assertion of the presumption of truth on behalf of the authority of what is revealed by Scripture and taught by Church tradition. Once reason accepts this presumption, it must then assume the task to verify, by means of philology, textual criticism and history, the authenticity of revelation and tradition. This type of procedure, far from being a rational demonstration of a necessary truth, Leibniz qualifies as ‘moral certitude,’ a kind of juridical reasoning that weighs the evidence and judges the credibility of testimony. The legitimacy of the presumption finally rests, then, on the claim that it is God who has spoken: however improbable they might be, biblical promises are morally credible because of the one who has made them. But are we not dealing with circular reasoning here? For do we not trust that God indeed has spoken on the basis of the testimony of scripture and the authority of tradition? Although in a footnote (p. 248 n. 71) the author admits that Leibniz overestimates the force of his moral argument, she never critically engages this crucial aspect of his thought. The whole project of philosophical theism falls into disrepute with Kant's critiques. Kant's famous comment about God's request of Abraham to sacrifice Isaac seems addressed specifically to Leibniz: ‘If God should really speak to a human being, one could still never know that it was God speaking.’