________________ 134 Introduction favour of Samghabhadra's monumental and more authoritative works against the Kosakara. The identification of the Dipakara with Vimalamitra could also be helpful in determining an approximate date of the Dipa. Vimalamitra is not a contemporary either of the Kosakara or of Samghabhadra, as he says that the latter's "qualities have been cherished through successive generations." It is not possible to determine the generations that separated Samghabhadra from Vimalamitra. But these could not have been many, for the memories of the dispute between the Kosakara and Samghabhadra are still fresh in the minds of (the generation of) Vimalamitra. Moreover, he must have flourished much earlier than Hsung's Tsang's visit to India, i.e. 629 A.D. The lower and upper limits of the date of Vimalamitra can thus be fixed between the dates of the Kosakara and of Hsuan Tsang. Tee date of the Kosakara) Vasubandhu is yet uncertain. Some place him in the middle of the fourth century and some in the fifth century A.D." But whether he is placed in the fourth or in the fifth century, it is unlikely that Vimalamitra can be placed beyond a hundred years after the Kosakara's death. The approximate date of Vimalamitra could thus be somewhere between 450 and 550 A.D. or even much earlier. The same date can hold good for the, composition of the Dipa. As we have noted above, all the acharyas referred to by the Dipakara belong to the pre-Kosakara period. No new doctrinal developments such as are found in the works of the post-Vasubandhu period are recorded in the Vritti. Indeed, the Dipakara's criticism of the Kosakara, and particularly his argumentations in defence of the Sarvastivada give an impression of their being contemporaries. We have no means of establishing any precise date, but one thing looks certain, that 1. Professor E. Frauwallner has given a complete bibliography on this problem in his monograph On the Date of the Buddhist Master of Law Vasubandhu (Serie Orientale Roma, III), Roma, 1951. Also see my article 'On the Theory of two Vasubandhus' in the BSOAS, XXI, 1, 1958, pp. 28-53.