Form, harmony, and mechanism in Leibniz's philosophy of laws.

摘要

In this dissertation I develop a sustained treatment of a topic that is neither well-understood nor much discussed, Leibniz's philosophy of laws of nature. Although all suspect that Leibniz endorses a causal powers account of laws, no one has succeeded in explaining his theory in great detail. While all recognize that the laws are closely related to his theory of nature's perfection, no one has clearly shown how Leibniz moves from his general analysis of perfection to his specific claims about the simplicity and explanatory strength of nature's laws. By explaining Leibniz's metaphysics of laws and his account of their relationship to perfection and scientific practice, I make progress toward better understanding a neglected region of Leibniz's philosophy.;I begin by situating Leibniz's project against the background of the Copernican Revolution. I argue that the Copernican Revolution brought about the decline of Aristotelian natural philosophy and the emergence of the mechanical philosophy. It was in this context that Leibniz developed a theory of laws that was designed to be at once Aristotelian and mechanistic. With the Aristotelians, Leibniz believed that any adequate philosophy of nature must include substantial form. With the moderns, however, Leibniz insisted that particular physical occurrences be explained mechanically, not by way of forms.;Having provided the historical context to Leibniz's project, I dedicate my third and fourth chapters to outlining Leibniz's causal powers account of laws and explaining his motivations for endorsing that theory. I argue that Leibniz analyzes the laws of nature as propositions expressing the ways bodies behave in virtue of their powers when operating with God's ordinary concurrence. I establish this claim by showing that this causal powers account is entailed by Leibniz's philosophy of force and that no other analysis is consistent with Leibniz's belief that the laws could be perpetually violated.;In my fifth chapter I investigate the relationship between the laws and nature's perfection. I argue that Leibniz's account of nature's perfection entails that the laws are coextensive with the axioms and theorems of the best deductive system true of nature. My argument begins by explaining Leibniz's harmony theory of perfection, according to which harmony consists in unity in variety. I show that the variety of a system is determined by the degree of change characterizing the system and that the unity of a system is determined by the number of primitive concepts required to comprehend the system. Applying this theory of perfection to nature, I show that the perfection of nature is determined by the extent to which it is explicable in terms of a deductive system that is both empirically adequate and simple. Leibniz regards a theory as simpler than another if fewer primitive concepts are required for its comprehension than is required for the comprehension of its rival. Because nature's perfection is determined by the degree to which a greater amount of its phenomena are comprehensible by fewer primitive concepts, Leibniz is able to justify simplicity as a theoretical virtue on the grounds that in the best possible world nature is as perfect as it could be.;In my final chapter I argue that once the role of primitive concepts in Leibniz's theory of nature's perfection is clarified, it becomes clear why Leibniz regarded all non-mechanistic explanations of natural phenomena as both unintelligible and inconsistent with the perfection of the physical world. I argue that what Leibniz found so objectionable about primitive gravitational power is that it resists full reduction to distinct primitive concepts. Leibniz's insistence that all explanations be reducible to distinct primitive concepts also explains his peculiar views about the proper role of substantial form in natural philosophy. The reason that substantial form can directly explain the laws themselves but not particular physical occurrences is because the former but not the latter admits of full reduction to distinct primitive concepts.