 Connected to the concept of emergence is top-down or downward causation. It captures the autonomous and genuine causal power of higher-level entities or states, especially upon lower-level ones. The most extreme and most controversial version include a violation of laws that regulate the lower-level (Meehl and Sellars 1956; Campbell 1974). Weaker forms require compatibility with the microlaws (for a brief survey and discussion see Robinson 2005; on downward causation without top-down causes, see Craver and Bechtel 2007, Bishop 2012). The very concept has become the subject of some interdisciplinary interest in the sciences (Ellis, Noble and O’Connor 2012).