After a brief analysis of the nature of occasional causation, distinguishing it from both efficient causation and the doctrine of occasionalism, it is argued that this model of causation informs Descartes' account of the generation of sensory ideas in the mind. It is further argued that, consequently, Descartes is not an occasionalist on this matter.

Four-dimensionalism, the stage theory version in particular, has been defended as the best solution for avoiding vagueness in regards to composition, persistence and identity. Stage theory is highly problematic by itself, and the two views usually packed with it, unrestricted composition and counterpart theory, are a heavy burden. However, dispensing with these two views, four-dimensionalism could avoid vague persistence by issuing a criterion that would establish sharp temporal boundaries for the existence of genuine entities (simples, molecules and living organisms). This (...) would avoid vague existence and vague identity, but in a way that is still compatible with endurantism. Nevertheless, a minimal (substantialist) four-dimensionalism, a worm perdurantist ontology, would fit better with the unique way in which organisms persist: by retaining both identity and intrinsic change. (shrink)