Idealism in the Viṃśatikā and Idealism in the Triṃśikā

It has been pointed out in Schmithausen 1967 (i.e. “Sautrāntika-Voraussetzungen in Viṃśatikā

(The ‘Twenty Verses’, a key Yogācāra work by Vasubandhu which can be viewed as a companion to his Triṃśikā. ..) The treatise discusses the nature of perceptual objects but interpretation of the text is controversial since it may be understood either as an ontologically orientated refutation of the existence of all external objects, or else in an epistemological sense which suggests that objects as they appear to the mind are merely contructs superimposed upon an indeterminate external reality. The work survives in Sanskrit as well as a Tibetan and two Chinese translations. Triṃśikā”) that the idealism in Vasubandhu’s Viṃśatikā (Viṃśatikā vijñaptimātratāsiddhiḥ) has not been developed on the basis of the Yogācāra’s concept of the “eightfold complex of mental series” (i.e. rnam shes tshogs brgyad) but on the basis of the Sautrāntika concept of the “one-layered mental series.”

Such an idealism developed on the basis of the “one-layered mental series” of the Sautrāntikas can also be found in Dignāga’s Ālambanaparīkṣā and Dharmakīrti’s writings. The idealism in Vasubandhu’s Triṃśikā, however, has been developed on the basis of the Yogācāra’s concept of the eightfold complex of mental series. dictionary.buddhistdoor.com