Leibniz's "Analysis of Multitude and Phenomena into Unities and Reality"

Leibniz's "Analysis of Multitude and Phenomena into Unities and Reality" DONALD P. RUTHERFORD 1. INTRODUCTION A REFRAIN OFTEN HZARD in Leibniz's later writings is that bodies, by their very nature as "multitudes" or "aggregates" of material parts, presuppose the existence of monadic substances. In the New Essays, his book-length response to Locke, Leibniz writes: "It should be borne in mind that matter.., is nothing but an aggregate [areas] or the result of one; and that any real aggregate presupposes simple substances or real unities" (A 6, 6: 378/RB 378). Similarly, in the "Principles of Nature and of Grace," he states that "Compounds, or bodies, are multitudes, and simple substances--lives, souls, and spirits--are unities. There must of necessity be simple substances everywhere, for without simple substances there would be no compounds" (GP 6: 598/L 636 ). Again, in section 2 of the "Monadology," we read: "There must be simple substances, since there are compounds, for the compound is but a collection or an aggregate of simples" (GP 6: 6o7/L 643).' A list of abbreviations for the primary sources cited in this article is given at the end of the essay. Versions of this paper were read at Reed College, Purdue University, and Emory University, and to the Leibniz group of the 1988 NEH Institute in Early Modern Philosophy. In each case, I would like to thank my audiences for their helpful comments. Special thanks are owed to Janet Broughton, Daniel Garber, Benson Mates, Steven Nadler, and George MacDonald Ross,each of whom provided valuable suggestions for revisions of earlier drafts. Initial work on this paper was supported by a Doctoral Fellowship from the Social Sciencesand Humanities Research Council of Canada. ' In what follows, I assume that the expressions "multitude," "compound," "aggregate," and "collection" lamas,assemblage]are all roughly synonymousfor Leibniz. This maybe an oversimplification . Leibniz often uses the terms "aggregate" and "collection" to designate so-called "corporate entities" (e.g., armies and herds), whose unity and identity qua singular things are determined by the particular relations holding among their individual members. Since the term "multitude" may [525] 526 JOURNAL OF THE HISTORY OF PHILOSOPHY 28:4 OCTOBER 199o The key to these notoriously cryptic passages, I believe, is to be found in Leibniz's simplest analysis of the concept of bodywwhat he describes in a letter to de Voider as his "analysis of multitude and phenomena into unities and reality" (GP 9: 27o). As this passage indicates, Leibniz's analysis of the concept of body is closely connected to considerations of the reality of body. In the "New System," he explicitly says that "a multitude can have its reality only from true unities" (GP 4:478/L 454). When taken in conjunction with the passages quoted above, this statement suggests that bodies are real precisely because the existence of any body, qua compound or multitude, presupposes the existence of monads, qua unities. In what follows, I shall contend that this is in fact Leibniz's position. If this is so, however, it remains unclear at the outset why the presupposition of monads by bodies should bear on the reality of bodies. How does just this fact support the proposition that bodies are, in some sense, "real beings," and not mere appearances? I shall argue that this connection holds because the presupposition relation between the existence of bodies and the existence of monads is predicated on a relation between the metaphysical essences of material things and monads. Insofar as any body is, by its nature, a mu/t/tude of things (manifestly, a multitude of material parts), Leibniz holds that it could only exist insofar as it is, under some description, a multitude of true unities. This conclusion is one of conceptual necessity: that there exist actual multitudes in the world implies that there exist actual unities . More than this, it implies that the compound entities we call "bodies" are, when accurately analyzed in terms of their essence, multitudes of true unities. From this follows the reality of bodies: if monads are real things, and bodies are by nature multitudes of monads, then bodies are (derivatively) real things as well. It is obvious that this...