 The mythologized, hagiographic character of the traditional biographies, together with the (disputed) belief that they contradict one another, has led a number of modern scholars to doubt their veracity. Many have expressed doubts that the mass of extant texts attributed to Vasubandhu in the Tibetan and Chinese canons could have been written by a single individual. In the 1950s Erich Frauwallner proposed a thesis that there were two separate Vasubandhus, whom the traditional biographies mistakenly combined into one  figure.[7]  Versions of this theory hold sway in some areas of the academy. Some scholars have called into question the story of Vasubandhu’s conversion from Śrāvaka (non-Mahāyāna) to Yogācāra under the influence of his brother Asaṅga, by noting a more gradual set of transitions and commonalities across works previously thought to sit on opposite sides of this  “conversion.”[8]  An extension of this argument, advocated today by Robert Kritzer and colleagues, holds that Vasubandhu was secretly an advocate of Yogācāra all  along.[9]