 Claims like 1 describe a relation which holds between token causes and effects—but what are token causes and effects? What are the relata of the token causal relations described by claims like 1? One popular view is that token causes and effects are events (Davidson 1963, 1967; Kim 1973; Lewis 1986b—see the entry on  events).  Others hold that token causes and effects are facts (Bennett 1988; Mellor 1995—see the entry on  facts).  Within the causal modeling approach (see the entry on  causal models),  it is often assumed that causes and effects are the values of variables (Hitchcock 2001a; Woodward 2003; Halpern &amp; Pearl 2005; Hall 2007; Halpern 2016a). One also finds support for other relata like conditions (J. L. Mackie 1965), event allomorphs (Dretske 1977), tropes (Campbell 1990), states of affairs (Armstrong 1997; Dowe 2000: ch. 7), situations (Menzies 1989a), and aspects (Paul 2000). Allegiances are complicated by disagreements over what events, facts, and these other creatures are. For instance, for both Bennett and Mellor, facts are just states-of-affairs which obtain, bringing their position in line with Armstrong’s. And, amongst those who agree that the causal relata are events, there is considerable disagreement about what exactly events are.