With regard to the third Piṭaka, called Abhi-dhamma (Abbhi-dharma, ‘further dharma’), which is held by modern scholars to be of later origin and supplementary to the Sutta (p. 62), it contains seven prose works[29]. Moreover, it was once thought to relate entirely to metaphysics and philosophy; but this is now held to be an error, for all seven works treat of a great variety of subjects, including discipline and ethics. Metaphysical discussions occur, but it is probable that originally Buddha kept clear of metaphysics (see p. 98). Besides the numerous works we have thus described as constituting the Tri-piṭaka or three collections of works of the Southern Buddhists, there are the Pāli commentaries called Aṭṭha-kathā (Artha-kathā, ‘telling of meanings[30]’), which were translated into Sinhalese, according to tradition, by Mahendra himself. Afterwards the original Pāli text was lost and some of the commentaries were retranslated into Pāli by Buddha-ghosha, ‘he who had the very voice of Buddha,’ at the end of the fourth and beginning of the fifth century of our era. The Mahā-vaṉṡa or ‘history of the great families of Ceylon,’ a well-known work (written in Pāli by a monk named Mahā-nāma in the fifth century and translated by Turnour), gives an account of this writer[31]. It says that a Brāhman youth, born near Buddha-Gayā in Magadha, had achieved great celebrity as a disputant in Brāhmanical philosophy. This youth was converted by a Buddhist sage in India, and induced to enter the Buddhist monastic Order. He soon became renowned for his eloquence, and was on that account called Buddha-ghosha. He wrote a commentary, called Aṭṭha-sālinī, on the Dhamma-saṅgani, a work belonging to the Abhi-dharma. He also wrote a most valuable Pāli compendium of Buddhist doctrine called Visuddhi-magga, ‘path of purity,’ and a commentary on the Dharma-pada containing many parables. He went to Ceylon about A.D. 430 for the purpose of retranslating the Sinhalese commentaries into Pāli. His literary reputation stands very high in that island, and he was instrumental in spreading Buddhism throughout Burma. It may be noted that the two important Pāli works, Mahā-vaṉṡa and Dīpa-vaṉṡa (Dvīpa-vaṉṡa), perhaps the oldest extant histories of Ceylon, are also fairly authentic sources for Buddhistic history before Christ. Turn we now to the Mahāyāna or ‘Great Vehicle.’ This cannot be said to possess any true Canon distinct from the Tri-piṭaka, though certain Nepalese Sanskṛit works, composed in later times, are held to be canonical by Northern Buddhists. To understand this part of the subject we must revert to the great king Aṡoka. It is usual to call this second and more celebrated Aṡoka the Constantine of Buddhism. Being of Ṡūdra origin he was the more inclined to favour the popular teaching of Gautama, and, as he was the first king who adopted Buddhism openly (about 257 B.C.) he doubtless did for Buddhism very much what Constantine did for Christianity.