Obviation versus Blocking. Two approaches to the distribution of anaphors and pronominals have been explored in Binding Theory. The OBVIATION approach, originating in Lasnik 1976 and extensively developed in the GB tradition, posits autonomous disjoint reference principles which directly filter out illicit coindexations in certain structural domains. The BLOCKING approach treats disjoint reference derivatively, by making anaphors obligatory under coreference in the binding domain, and invoking a syntactic or pragmatic principle that forces disjoint reference pronominals in the “elsewhere” case.