Aryadeva

Āryadeva (c. 170–270 CE), counted as the fifteenth Chan patriarch, was Nāgārjuna's principal disciple and the chief expositor of Madhyamaka in the second generation^[1]. He is a securely historical figure with a verifiable corpus of works preserved in Sanskrit, Chinese, and Tibetan. Tibetan tradition records that he was born in Sri Lanka or southern India, possibly to a royal family, and traveled north to study with Nāgārjuna; some accounts say he encountered his teacher at Nāgārjuna's mountain hermitage of Śrīparvata in Andhra^[2].

Āryadeva's principal work is the *Catuḥśataka* (Four Hundred Verses on the Middle Way), a sixteen-chapter polemical and analytical treatise that extends the *Mūlamadhyamakakārikā* into the domains of practice, ethics, and refutation of non-Buddhist positions. The first eight chapters address bodhisattva conduct; the second eight refute the philosophical positions of the Sāṃkhya, Vaiśeṣika, and Jain schools^[3]. He is also the author of the *Śataśāstra* (Hundred Verses), preserved only in Kumārajīva's Chinese translation, which together with Nāgārjuna's *Mūlamadhyamakakārikā* and *Twelve Gates Treatise* (*Dvādaśadvāra*) forms the textual basis of the Chinese Sānlùn ("Three Treatises") school of Madhyamaka^[4].

A famous traditional detail records that Āryadeva had only one eye, having offered the other in donation; this anatomical feature gives him the alternative name *Kāṇadeva* ("Deva of the One Eye") in Chinese sources^[5]. Hagiographical accounts describe his death by violent assassination at the hand of a brahmin disputant whom he had defeated in debate, with Āryadeva accepting the blow as the resolution of a karmic debt and dying while expounding emptiness one last time^[6].

In the Chan reckoning Āryadeva transmitted to Rāhulabhadra (Rahulata)^[7]. His position in the lineage marks the close of the Madhyamaka founders' generation; subsequent Indian patriarchs in the Chan list belong to a different stratum of legendary or semi-legendary teachers.