 The Yogācāra’s claim that external objects are not even conventionally real, what is conventionally real are only our impressions, and mental representations is one Vasubandhu closely defends by means of the Yogācāra’s theory of the three natures (trisvabhāva). In his Discernment of the Three Natures (Trisvabhāvakārikā, or Trisvabhāvanirdeśa [TSN]; Sems tsam shi 10a–11b), Vasubandhu explains that the Yogācāra ontology and phenomenology as consisting of the unity of three natures (svabhāva):