“Both Diṅnāga and Dharmakīrti seem to accept here the Sautrāntika atomism along its theory of external realities but this may be only a tentative concession” (Matilal 1986: 366). “Buddhist atomism reduces the spatial extension of external realities to atoms, the infinitesimals” (Matilal 1986: 367). Some Tibetan sources distinguish three conventions accepted by Diṅnāga and Dharmakīrti: (a) one non-analytical world-conforming convention, and two analytical-śāstric conventions, namely, (b) Sautrāntika’s convention which conforms the conventional mode of appearance (tha snyad snang tshul), and (c) Yogācāra’s convention which conforms the conventional mode of existence (tha snyad gnas tshul). Accordingly, Diṅnāga and Dharmakīrti, following conventional mode of appearance would accept Sautrāntika atomism, but Yogācāra idealism from the perspective of the conventional mode of existence. To be noted is that most phenomena considered to be substantially existent by the Vaibhāṣika school are said to be considered to be non-substantial (i.e. only nominally existent) by the Sautrāntika school. See, for example, dKon mchog ’grel (pp. 44.23–45.2).