Mahâ-Parinibbâna-Suttanta: The Book of the Great Decease

It would result from the first calculation that the date of Asoka's coronation would be 325 B.C. (146 + 161 + 18). But we know that this must contain a blunder or blunders, as the date of Asoka's coronation can be fixed, as above stated, with absolute certainty within a year or two either way of 267 B.C. Would it then be sound criticism to accept the other, earlier, period of 236 years found in those chronicles--a period which we cannot test by Greek chronology--and by simply adding the Ceylon calculation of 236 years to the European date for the eighteenth year of Asoka (that in circa 249 B.C.) to conclude that the Buddha died in or about 485 B.C.? I cannot think so. The further we go back the greater does the probability of error become, not less. The most superficial examination of the details of this earlier period shows too, that they are unreliable; and what reliance would it be wise to place upon the total, apart from the details, when we find it mentioned for the first time in p. xlvii a work, the Dîpavamsa, written eight centuries after the date it is proposed to fix? If further proof were needed, we have it in the fact that the Dîpavamsa actually contains the details of another calculation--based not on the lists of kings (Râga-paramparâ), but on a list of Theras (Thera-paramparâ) stretching back from Asoka's time to the time of the great Teacher--which contradicts this calculation of 236 years.