^{page 51 note 1} Russell, Bertrand, The Philosophy of Leibniz, Allen and Unwin Ltd., London, Second Edition, 1948, p. v.Google Scholar

^{page 52 note 1} Loemker, L. E., Gottfried Wilhelm Leibniz, Philosophical Papers and Letters, University of Chicago Press, Chicago, 1956, pp. 413, 415, 417.Google Scholar

^{page 52 note 2} Wiener, P. P., Leibniz Selections, Charles Scribners Sons, New York, 1951, pp. 94–5. Hereafter this book will be referred to as Wiener. Almost all subsequent quotations from Leibniz writings will be drawn from Wiener’s excellent selection. His book provides ready access to material which otherwise is not easily available to most students of philosophy.Google Scholar

^{page 53 note 1} Wiener, pp. xxi-ii.

^{page 53 note 2} Wiener, p. 51 (The Art of Discovery, 1686), and p. 59 (On True Method in Philosophy and Theology, 1686).

^{page 53 note 3} Wiener, p. 49 (On True Method in Philosophy and Theology, 1686), p. 17, (Towards a Universal Characteristic, 1677). Loemker, in Philosophical Papers, points out that “Leibniz shared the Aristotelian and Scholastic conviction that logic is a tool of thought—and that it must be grounded in the universal, self-differentiating harmony which is reflected imperfectly in individual substances. His logical studies aimed to provide the instruments by which man can grasp the structure of being in his own symbolic formulas” (p. 40). In somewhat similar fashion, Schrecker (Journal of the History of Ideas, Vol. VIII, No. 1, p. 109) states: “The very essence of mathematics was indeed metaphysically founded. And therefore mathematics, in spite of its formal character, was not merely a formal but a real science—representing— independent reality beyond the human mind.”

^{page 54 note 1} Wiener, pp. 101–2 (Whether the Essence of a Body Consists in Extension, 1691).

^{page 54 note 2} See Wiener, pp. 369–70 (New Essays, 1704).

^{page 55 note 1} Wiener, p. 364 (On the Supersensible Element in Human Knowledge, 1702) and pp. 370–1 (New Essays, 1702) (emphasis added).

^{page 55 note 2} Wiener, p. 160 (On Substance as an Active Force Rather Than Mere Extension, 1699), and p. 157 (On Substance as an Active Force Rather Than Mere Extension, 1699).

^{page 55 note 3} Wiener, p. 177 (Letter to De Volder, 1702). See also L. E. Loemker, Journal of the History of Ideas, Vol. VII, No. 4, p. 408, and Vol. XVI, No.1, p. 33.

^{page 56 note 1} It will have been noted that quotations from the writings of Leibniz, used in this discussion, have been identified in terms of source, and dated (whenever possible). This was done in order to facilitate a comparison of earlier and later Leibnizian comments. The contention that with the passage of time a shift in emphasis from rational to empirical occurred in Leibniz's thought is accepted by L. E. Loemker who cogently remarks that “with the failure of Leibniz's logical construction of metaphysics it is the empirical pattern of his philosophy which comes into prominence.—His critics have not generally appreciated the magnitude of the change in emphasis which Leibniz's thought underwent in the 1690's.—It is not too much to say that questions of essence are now subordinated to the investigation of well ordered phenomena and their essential and existential structures”. (“Leibniz's Judgments of Fact”, Journal of the History of Ideas, Vol. VII, No. 4, p. 408.)

On the other hand Wiener's interpretation is couched in somewhat different words: “Leibniz constantly strove to reconcile the a priori elements of demonstrative reasoning with the more empirical side of scientific method.” In Wiener's judgment this attempt at reconciliation was not successful. “There was, then, a significant oscillation in Liebniz's writings between his a priori system of irreducible real definitions and the experimental aspect of his program for the use of logic as an instrument of discovery, and invention.” (Leibniz: Selections (Scribners, New York, 1951, pp. xxiii and xxvi.) (Emphasis added.)

In any case, both Loemker and Wiener would agree with R. L. Saw (Leibniz, Penguin Books, p. 20) who points out the very fundamental fact that “An interpretation of the system of Leibniz as a purely logical one would not have satisfied Leibniz himself. He states ‘let no one be afraid that the contemplation of signs will lead us away from things. On the contrary it will guide us to the innermost nature of things’. Again he says ‘Truths do not depend upon names and are not arbitrary as some of our new philosophers think’” (Discourse on Metaphysics, Section 24).

^{page 58 note 1} See Wiener, p. 529 (The Principles of Nature and Grace, 1714); and, Discourse on Metaphysics, Sections 26, 30, 36.

^{page 58 note 2} See Wiener, p. 107–8 (New System of Nature, 1695), and p. 63 (On True Method in Philosophy and Theology, 1686).

^{page 59 note 1} See Wiener, pp. 107; 522–6 (New System of Nature, 1695); (The Principles of Nature and Grace, 1714).

^{page 59 note 2} See Monadology.

^{page 59 note 3} See Monadology, Section 87.

^{page 60 note 1} Wiener, p. 186 (On the Principle of Continuity, 1702), and see Loemker, L. E., Leibniz, Philosophical Papers and Letters, p. 50Google Scholar, and Cassirer, E., The Philosophy of the Enlightenment, Beacon Press (Paperback), Boston, 1955, p. 122.Google Scholar

^{page 60 note 1} See Friedmann, Georges, Leibniz et Spinoza, Librairie Gallimard, Paris, 1946, pp. 22–3.Google Scholar

^{page 60 note 3} This fact has been recognized and appreciated in varying degrees by a number of Leibniz's critics. For example, Joseph, H. W. B. (Lectures on the Philosophy of Leibniz, Oxford, 1949, p. 1)Google Scholar “Though he (Leibniz) taught that mathematical principles should be used in the explanation of nature—yet he also offended the scientific mind by saying that at bottom they were insufficient, and appealing to final causes and substantial forms.” Similarly Cassirer, E., The Philosophy of the Enlightenment, Beacon Press (Paperback) Boston, 1955, p. 29): Leibniz's monad “is no arithmetical, no merely numerical unit, but a dynamic one. —Each monad is a living center of energy”. With customary insight Loemker expresses the situation clearly and in considerable detail. “As Leibniz fully recognized, this work can not establish a panlogism (he is referring to ‘Primae Veritates’), and even less a metaphysics of plurality, and change, for it professes to be only a derivation of his fundamental principles from the laws of identity and reason.” Loemker points out further that “it is also true that for a few years from 1679 to 1687—he proposed what he called an ‘argument’ from logical principle to his theory of individual substance. It was not an argument, however, but the arbitrary imposition of a logical doctrine upon a metaphysical one. Nor was it carried over into his mature thought”, (Journal of the History of Ideas, Vol. VII, No. 4, pp. 398, 401. See also pp. 402–8.) More specifically, Loemker refers to the influence of Leibniz's studies in physics and psychology and summarizes his interpretation in the following fashion: “Leibniz's philosophy is affected at different periods by the particular special studies in which he is engaged. Of this, the outstanding example is the fading of the logical interests from the first place in his thoughts—and its replacement by the physical studies of the 1690's.—Beginning with the Specimen Dynamicum the universal harmony is pushed into the background and force to the center, the law of individuality becomes abstract and formal, and the actual dynamic process the concrete and real. The claims of demonstration are weakened and the hypothetical nature of his philosophy emphasized. The eternal chain of being gives way, in emphasis, to the temporal order of progress, so that in his last philosophical statements the Platonic doctrine of ideas on which his thought is always based is not explicit, logic is subordinated to epistemology, while psychology, biology and history are in the foreground.” (Leibniz, Philosophical Papers and Letters, pp. 22–3.) See also the valuable sketch of Leibniz's early philosophical position and the influences which affected him, in particular some phases of Renaissance thought—in Leibniz et Spinoza by G. Friedmann, Chapter 1 (Librairie Gallimard, Paris, 1946).Google Scholar

^{page 61 note 1} See Russell, B., The Philosophy of Leibniz, Second Edition (George Allen and Unwin Ltd., London, 1937), p. vi.Google Scholar