The concept of transition and its role in Leibniz’s and Whitehead’s metaphysics of motion

Leibniz’s and Whitehead’s analyses of motion are at the heart of their metaphysical schemes. These schemes are to be considered as two blueprints of a similar metaphysical intuition that emerged during two breakthrough eras, that is, the 17th century and the beginning of the 20th century, and retained the Aristotelian idea that existence requires an active principle. The two philosophers’ attempts to elucidate this idea in the context of their analyses of motion still interact with central, longstanding questions in philosophy, in particular that concerning the ontological status of change. For both thinkers, the phenomenon of motion is an example par excellence, of the metaphysically fundamental principle of action that is required for change in the world. I focus on Leibniz’s and Whitehead’s similar understanding of the concept of transition that is inserted as an essential constitutive component of motion and ensures its status as something real.     

Supervenience and (non-modal) reductionism in Leibniz’s philosophy of time

It has recently been suggested that, for Leibniz, temporal facts globally supervene on causal facts, with the result that worlds differing with respect to their causal facts can be indiscernible with respect to their temporal facts. Such an interpretation is at variance with more traditional readings of Leibniz’s causal theory of time, which hold that Leibniz reduces temporal facts to causal facts. In this article, I argue against the global supervenience construal of Leibniz’s philosophy of time. On the view of Leibniz defended here, he adopts a non-modal reduction of time to events, a form of reductionism that entails a strong covariation between a world’s temporal facts and its causal facts. Consequently, worlds discernible with respect to their temporal facts must be discernible with respect to their causal facts, and worlds discernible with respect to their causal facts must be discernible with respect to their temporal facts. This position strongly favors the standard identificatory reduction of time to causation often imputed to Leibniz.