 Salmon termed his conception of explanation ontic, as opposed to the epistemic conception heralded by Hempel, and the erotetic approach defended by van Fraassen (Salmon 1985a [1998] and 1982b [1998]). According to the ontic viewpoint events are explained by showing how they fit into the mechanisms operating in the world, and the causal processes and interactions of which mechanisms are compounded are physical entities. In Salmon’s words: