 The problems with the conventional legal analysis of causation—in terms of a bifurcation into cause in fact and proximate causation—have tempted some legal theorists to abandon the bifurcation of causation in the law and to search for a unitary notion of causation that is much more discriminating (in what it allows as a cause) than the hopelessly promiscuous counterfactual cause-in-fact test of the conventional analysis. Indeed, the search is for a unitary concept of causation that is so discriminating that it can do the work that on the conventional analysis is done by both cause-in-fact and proximate cause doctrines. It is far from obvious that causation is in fact a sufficiently discriminating relation that it can do this much work in assigning responsibility. Nonetheless, there are three such proposals in the legal literature, each having some doctrinal support in the law.