Journal of the History of Philosophy

BOOK REVIEWS 121 of reality. As it stands, the present volume makes available to scholars a collection of sources which will prove essential to understanding the way in which early modern Europe received and reacted to one of Plato's most enduring images. FREDERICK PURNELL, JR. Queens College and The Graduate Center, C.U.N.Y. Nicholas Rescher. Leibniz's Metaphysics of Nature. The University of Western Ontario Series in Philosophy of Science, vol. a8. Dordrecht, Boston and London: Reidel, 1981. Pp. xiv + 1~6. $31.5 ~ cloth; $14.5o, paper. This volume contains seven essays, three of them heretofore unpublished, dealing with Leibniz's cosmology and metaphysics. In an introduction Rescher summarizes the particular themes as follows: Leibniz's conception of creation as a choice among an infinite set of compossible alternatives; his epistemology and theory of scientific inquiry; the role of system in his thought; the nature of contingency; the theory of relations; spaceLtime; and the contribution of Leibniz's mathematics to his metaphysics . The collection is attractively appended with an account of Rescher's life-long interest in, and devotion to, Leibniz's work, and a bibliography of his papers and books on the Sage of Hannover. The guiding motif of the book, a motif which unifies what might otherwise be a mere collection of occasional pieces, is the idea of infinity which, as Rescher notes, clearly indicates Leibniz's modernism and his break with the closed finitistic world of antiquity. It is immediately evident, however, that this theme of infinity is to be understood in coordination with another of Leibniz's paramount principles, that of perfection. These govern many of the characteristic moves in Leibniz's thought, from the creation of a world infinitely varied but perfectly ordered, through an epistemology of coherence and system, and the characteristic treatments Leibniz gives to problems of contingency, relation and the space/time configuration of the world. Rescher rightly observes in his first essay that this principle of perfection is a much-neglected aspect of Leibniz's metaphysics. There is an ethics of creation which guarantees that the world which comes to be out of the bottomless well of possibility, will be one characterized by the maximum degree of variety compatible with the minimum number of governing laws. This principle of economy, with the rich ethico -aesthetic connotations Leibniz applies to it, constitutes one of the great neglected a prioris of the system. The epistemological counterpart (Essay 2) of these metaphysical themes is remarkably empiricist in tone and emphasizes a coherence theory of truth. It refers of course to human knowledge, not divine. That is to say, the validation of themes of economy, perfection and sufficient reason in our knowledge of the universe, is essentially founded in sense perception and the inductively justified mesh of experience over a period of time. Observation and experiment constitute our (admittedly imperfect) glimpse of the world perfectly calculated by God. This empiricism leads us inexorably to examine the usefulness of characterizations of Leibniz as 122 JOURNAL OF THE HISTORY OF PHILOSOPHY 22:1 JAN 198 4 the great 'Rationalist,' although the repeated emphasis upon a theory of divine cognition and a description of our knowledge as successively approximating God's, should keep us from pushing Leibniz too far into the classic opposing camp. Considerations of coherence and "fit" lead Rescher in the third essay to examine Leibniz the "systematic" thinker. Here too concepts of infinity and perfection provide the key, since a system is nothing other than the interweaving of an ideally simple and elegant set of principles with an infinitely rich content. Leibniz characteristically finds himself here astride classic and modern theories of systematism. He affirms the rational and systematic nature of the real world and the need to introduce system into cognitive reflections on reality. This latter desideratum leads Leibniz to modify classic Euclidean conceptions of procedure in favor of the model of modern calculus, better suited to an infinitely complex universe. The twin themes of infinity and perfection come to bear most fruitfully in Rescher's account of contingent propositions and the infinite analysis needed to demonstrate them (Essay 4). The principle of perfection accounts for the fact that contingent...