Descartes and Spinoza on the Laws of Nature

Abstract

Abstract This chapter develops Hampshire’s claim that Spinoza’s system “can … be fairly represented as the metaphysical expression of the ideal … of a unified science.” Descartes believed that we could organize the sciences into a deductive system whose axioms are metaphysical principles, from which the laws of physics are deducible, and that the laws of all the other sciences are deducible from physics. Spinoza agreed with much of this, but questioned Descartes’ foundations. He did not think we could deduce the laws of nature from the will of God (or from such traditional attributes of God as immutability and omnipotence). Instead he thought we could deduce them from the attributes, which are his first cause. If we develop Hampshire’s insight in this way, and recognize that Spinoza thought the causal structure of nature must reflect the logical structure of the ideal science, we will better understand the nature of his ‘God,’ the causal relation between God and his ‘creatures,’ what the infinite modes are and why Spinoza thought they must exist, and in what sense his system is necessitarian.