Spinoza’s Ethics E4p18s on the Dictates of Reason

In an intriguing passage of the Ethics ( E 4p18s), Spinoza offers, by his own lights, a sketch of his general moral theory. In this paper, I develop an overlooked moral realist interpretation of Spinoza’s sketch of his moral theory. I argue that this moral realist interpretation makes better sense of textual evidence than the Hobbesian, antirealist interpretation proposed by Curley (1988) and recently developed by Zuk (2015). First, I explain how Spinoza sets out from conatus-based, prudential desires to argue for the crowning ‘dictate of reason’ that I shall call ‘ the objectivity of moral reasons principle’ . Second, I explain how Spinoza indicates a virtue-theoretic, moral epistemology for responsiveness to ‘dictates of reason’. Third, I examine the alternative, Hobbesian relativist interpretation of the passage proposed by Curley (1988) and Zuk (2015) and argue that the moral realist interpretation is overall more plausible. I conclude that E 4p18s better supports a moral realist interpretation of Spinoza’s Ethics . Given that, as Spinoza repeats twice, E 4p18s provides a sketch of his moral theory, this is some interesting evidence in favor of the moral realist interpretation.