Abstract

What kinds of things are we committed to if Acting-Entity (AE)-mechanisms exist? Defenders of the AE-approach to mechanisms argue that mechanisms are organized entities and activities. This entity–activity dualism is understood as a metaphysical claim: the fundamental units of mechanisms are entities and activities that cannot be reduced to anything more fundamental. In this chapter I investigate this claim. In the first section, I analyze the notion of an entity. In the second section, I illuminate the notion of an activity. To combine the results from these two sections, and in order to accommodate the criticisms of entity–activity dualism that I bring forward, in the third section I introduce the notion of an entity-involving occurrent. In the fourth section, I elaborate on one central motivation for introducing the notion of an activity: activities are supposed to be essentially causal, and thus are the kinds of things that bring causation into the world. How this is supposed to happen is, so far, not well understood. I illuminate this idea and introduce a new account of causation: activity causation.