AbstractThis paper focuses on Sāṃkhya-Yoga and Buddhist Abhidharma ontologies and their engagement. A close reading of two hitherto uncompared passages from Pātañjalayogaśāstra 2.13 and Vasubandhu’s Abhidharmakośabhāṣya 4.94 suggests that they are intertextual or interdiscursive. A mirrored argument form in the texts explains ethical causality (karma) in relation to rebirth (punarjanman). The arguments in both texts are similar in form, sequence, and even conclusion, although not in terms of the doctrinal basis of reasoning. On first examination, both arguments analyse how action (karma) sustains patterns of moral repercussion across life and beyond death in terms of singular and plural causes and effects. But a close reading shows that the level of conceptual engagement on this issue is more nuanced – centred on ‘projecting’ and ‘completing’ mechanisms of karmic retribution (ākṣepaka karman and paripūraka karman) as well as determinate or indeterminate (niyata and aniyata) maturation of karmic effects. The paper suggests that the function of Patañjali’s passage was to serve as a structured engagement with Buddhist Sarvāstivāda karma theory.