This article investigates Abū Rayḥān al-Bīrūnī’s Arabic engagement with Patañjali’s Yoga Sūtras, focusing on his rendering of the Sanskrit term nidrā—conventionally “dreamless sleep”—as ruʾyā (“dream”). What may appear to be a mistranslation is argued to be a deliberate conceptual move shaped by the epistemological and psychological architecture of the Peripatetic (mashshāʾī) tradition in Islamic philosophy, especially the theory of the soul’s faculties (quwā al-nafs). Through a close reading of…
Read moreThis article investigates Abū Rayḥān al-Bīrūnī’s Arabic engagement with Patañjali’s Yoga Sūtras, focusing on his rendering of the Sanskrit term nidrā—conventionally “dreamless sleep”—as ruʾyā (“dream”). What may appear to be a mistranslation is argued to be a deliberate conceptual move shaped by the epistemological and psychological architecture of the Peripatetic (mashshāʾī) tradition in Islamic philosophy, especially the theory of the soul’s faculties (quwā al-nafs). Through a close reading of al-Bīrūnī’s Bātanjal al-Hindī fī al-Khalāṣ min al-Irtibāk, the article analyzes how he maps the five vṛttis—citta-vṛtti as consciousness fluctuations—onto the internal faculties (common sense, imagination, estimation, compositive power, memory). On this mapping, rendering nidrā as ruʾyā relocates a minimally contentful, dreamless state into the domain of imaginative activity, the sort of state that qualifies as a genuine faculty within Peripatetic psychology. The argument does not presuppose direct Sanskrit-to-Arabic translation; it rests on al-Bīrūnī’s Arabic formulations and remains compatible with transmission through intermediaries. Methodologically, the case shows that cross-tradition translation often proceeds by conceptual transposition rather than lexical equivalence. Substantively, it illuminates al-Bīrūnī’s intellectual strategy and the hermeneutical dynamics structuring medieval inter-Asian philosophical encounters. The study thus contributes to debates in comparative philosophy, translation theory, and the transmission of metaphysical psychology across civilizational boundaries.