 Other models of moderate realism were developed in the Sakyapa tradition, that also invoke the necessity for the existence of a real shared property without which our thinking would be arbitrary. Uyukpa Rikpé Senggé (ʼU yug pa Rigs paʼi seng ge, 13th c.), who adopts such a line of interpretation, explains Dharmakīrti’s refutation of real universals as referring to a “mental universal,” the mistaken conflation of distinct things under a unitary appearance. His view of an “objective universal” involves the theory of apoha, in a way that takes the exclusion from non-x as a fact rather than as a mental construct.