Journal of the History of Philosophy

In this paper I explain how Spinoza's ontological monism is related to the monotheism of a distinct tradition in medieval Aristotelianism exemplified by Maimonides. My main contention is that Maimonides' God, conceived as intellectual activity has the same structure as Spinoza's Deus sive Natura. The main difference between them is that Maimonides' God is confined to cognitive activity, whereas Spinoza's God is extensive activity as well. I trace the impact of the medieval doctrine of God on Spinoza's thought from the Cogitata Metaphysica to the Ethics, establishing conceptual parallels, literary links, and an explanation of the steps leading from the former to the latter.