Some Antecedents of Leibniz’s Principles by Martinho Antônio Bittencourt de Castro A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy School of History and Philosophy University of New South Wales Sydney, Australia April 2008 2 Declaration I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged. Date: 12 June 2008 3 Abstract Leibniz considered that scepticism and confusion engendered by the disputes of different sects or schools of metaphysics were obstacles to the progress of knowledge in philosophy. His solution was to adopt an eclectic method with the aim of uncovering the truth hidden beneath the dispute of schools. Leibniz’s project was, having in mind the eclectic method, to synthesise a union between old pre-modern philosophy, based on formal and final causes, and new modern philosophy which gave preference to efficient causes. The result of his efforts is summarised in the Monadology. But the question remains: to what degree was Leibniz successful in this enterprise? An objective of this thesis is to investigate whether philosophical tradition can justify or support some of the arguments that are at the basis of Leibniz’s system (for example, monads have no window to the exterior world, a phrase that summarises the structure of Monadology). I shall demonstrate how Leibniz reflects the concerns and the positions of his key predecessors. Thus, the aim of the thesis is to explore key antecedents to Leibniz’s central doctrines. The thesis argues that Leibniz carried out a logical development of some principles in the eclectic system of Plotinus, which resulted in the structure of Monadology. Whether Leibniz’s project was successful or not will depend on how we view those principles. 4 Acknowledgements I would like to thank my supervisor, Dr Michaelis Michael, for his assistance and useful discussions. I would also like to thank the School of History and Philosophy, mainly Dr Rosalyn Diprose and Dr Damian Grace. Thanks must also go to the Capes Foundation for the scholarship granted during the four years of the research. Finally I would like to thank my mother, Zulamar Maria de Bittencourt e Castro, for her support. 5 Contents Introduction 6 Chapter I – Context of this Thesis and Rationale for the Philosophers Chosen 10 Chapter II – Pythagoreans and Leibniz 16 Chapter III – Aristotle and Leibniz 50 Chapter IV – Plotinus and Leibniz 82 Chapter V – Proclus, the Cambridge Platonists and Leibniz 148 Chapter VI – The Tradition of Studies in Optics – al-Kindi and Grosseteste 172 Chapter VII – Nicholas of Cusa and Leibniz 196 Conclusion 217 Bibliography 221 6 Introduction This thesis is concerned with the philosophical system of the German philosopher of the seventeenth century, Gottfried Wilhelm Leibniz. He was a person of encyclopaedic knowledge and his readings covered as much as was possible for one person; thus the span of influences on him is very broad and we can cite only some of them: Aristotle, Aquinas, Descartes, Augustine, Galileo, Kepler, Francis Bacon, Suarez, Hobbes, Spinoza, Gassendi, van Helmont, Malebranche and Lullus. This broad span of interest is perhaps due also to the philosophical method that he acquired by contact with some eclectic scholars like Johann C. Sturm.1 In his book Eclectic Philosophy, Sturm presented as the goal and method of philosophy the idea that it was necessary to examine all significant intellectual traditions, and, by means of a proper critical analysis, to separate what was the genuine truth from what could only be considered merely the dogma of a sect. The fact, however, is that the search for synthesis or for a Perennial Philosophy that was beyond dispute was a task established well before Sturm. We can find this preoccupation in the Renaissance with Ficino and even before, for example, in the effort of the Neo-Platonists to merge the philosophies of Plato, Aristotle and the Stoics.2 Leibniz followed this tradition and considered that both scepticism and the confusion and disputes between the different sects of philosophy were obstacles to the progress of knowledge. His solution was the adoption of an eclectic method of uncovering the truth that was hidden beneath the dispute of schools: “It is not surprising therefore that throughout his life Leibniz studies a wide range of authors, that he is inclined to force comparisons between his own view and those of others thinkers, and that he often uses terms and philosophical jargon from odd collection of sources to express his own ideas.”3 Mercer and Sleigh also point out the importance of two of Leibniz’s teachers: Jacob Thomasius of 1Mercer and Sleigh in JOLLEY, N., The Cambridge Companion to Leibniz, Cambridge, Cambridge University Press, 1995, p. 69. Leibniz was in contact with Sturm by correspondence but the Sturm’s book was published only in 1686. 2 The search for a perennial philosophy by Ficino is discussed in KRISTELLER, P., The Classic and Renaissance Thought, Cambridge, Harvard University Press, 1955. 3 Mercer and Sleigh in JOLLEY, p. 70. 7 Leipzig and Erhard Weigel of Jena. Those two teachers stressed to Leibniz that the philosophy of Aristotle was already a basis or foundation for this eclectic enterprise. After the removal of distortions added by Scholasticism, this philosophy could be made consistent with the new findings of modern mechanics. But the science of Aristotle has as a central notion the concept of teleology, of final causes. It is an attempt to explain nature as penetrated by an effort to develop not yet existing forms. Any change or movement would be an expression of this trend, which was a kind of progress toward a goal. This notion was precisely the target of attack by the new science. The opposition to teleology was based on the fact that it seemed to close off the prospects for an explanation in terms of efficient causes, which was considered the true causal explanation. Moreover, teleology was also condemned for introducing an occult and non-observable factor, the entelechies or souls. Indeed, in the seventeenth century, modern thinkers started to consider Aristotelian science as a barrier to the progress of knowledge. In this direction, the founders of the modern science, Galileo and Descartes, suggested that the instrument most adequate to investigate nature was mathematics. In this movement Descartes contributed to the exclusion of final causes by substituting the Aristotelian entities (the entelechies) for a more simple reality, subject to mathematical treatment, extension (the res extensa).4 Cartesian reason, as applied in the res extensa, was founded in constant relations of mathematical language. It was, at least theoretically, reversible and consequently time had no place there. This created, however, a clear dualism: on one side the world of the spatially extended, geometric bodies, res extensa, knowable entirely by mathematics, and on the other side, the realm of mind, without extension, res cogitans, whose essence is thought and whose activity was mainly mathematical deductive operations. Descartes seemed not to be very interested in res cogitans; and he never appealed to final causes to explain what happens in the realm of the mind.5 The passivity of matter is a consequence of this Cartesian dualism. This led to the creation of the mechanist ontology: matter was considered perfectly inert and deprived of any sensibility or conscience; movement is no 4 This discussion appears in Meditations 5 and 6. DESCARTES, R., Meditation on first philosophy, trans. J. Cottingham, New York, Cambridge University Press, 1986. It appears also in DESCARTES, R., Principles of Philosophy, trans. V. R. Miller and R. Miller, Dordrecht, Kluwer Academic Publishers, 1983, Part 1 section 53. 5 BURTT, E. A., As Bases Metafísicas da Ciência Moderna, Brasília, Editora UnB, p. 95. 8 longer a symptom of inherent life, and is not guided by telos any more, but is a consequence only of external circumstances, basically the result of shocks or impacts. Leibniz saw as his project the task of synthesising a union between the old pre- modern philosophy, based on formal and final causes, and the new philosophy which gave preference to efficient causes. In this regard this was consonant with his eclecticism. He valued the mechanistic mode of explanation, but he affirmed with emphasis that this method has its foundation in the proper final doctrine of the cause. Finally, Leibniz considered that the same reconciliation of the two methods would be of great advantage for the proper scientific and particular knowledge of things. But the question remains as to what degree Leibniz was successful in this enterprise. The result of his effort is summarised in the Monadology. It is my objective to investigate whether the philosophical tradition can justify or support some of the arguments that are basic to the system of Leibniz (for example, that the monads have no window to the exterior word, a phrase that summarises the structure of Monadology). In following this historical enquiry I have also been led by some consideration of the Italian philosopher Rodolfo Mondolfo. As a member of the historicist school, Mondolfo stressed that the constitution of any reality can be found and reveals itself in its process of formation.