As can be seen in Monograph 3, there are more than ten biographical works that are considered scriptures. However, they all have severe limitations as biographies of the Buddha, since they relate only short sections of the Buddha's life, and do not stand up to scholarly verification.
A glance at Fig. 1 will show that such works are no more than depictions of specific events in the Buddha's life. Most of these biographical scriptures finish with either the conversion of Sāriputta and Moggallāna or the return of Sakyamuni to his native Kapilavatthu. They are based on the "Great Chapter" of the Mahāvagga. The Nidānakathā, which consists of the first part of the Pāli Jātaka, takes up the first year of the Buddha's ministry, from the time of his enlightenment under the bodhi tree.
Another group of biographical scriptures records the Buddha's death based on the "Nirvāna Sutras" that take the passing into Nirvāna as their subject. The Sanskrit Buddhacarita (The Acts of the Buddha) by Aśvaghoṣa (second century CE) and its Chinese translation Fosuoxingzan (Dharmarakṣa, 420) are among a number of other biographical works, but they do no more than list the events of the Buddha's life in no particular order, and make no attempt to avhieve a chronological record.
Of course modern scholars too have written studies of the Buddha's life, and I will introduce such works in my bibliography of biographical research that will be uploaded shortly. Even these however do not go beyond the bounds mentioned above. Thus down to the present no complete record of the Buddha's life exists.
Since the early Buddhist scriptures are a collection of works detailing events in the life of Sakyamuni, the Buddha, all could in fact be considered data for a biography. However, though they always begin by telling us where and to whom the sutra was spoken, and its subject, we are never told more about when the discourse occurred than "on one occasion" (e.g. "Thus have I heard. On one occasion the Blessed One was staying at Sāvatthī in the Jeta grove, the garden of Anāthapiṇḍika with a large gathering of 1250 monks..."). Since all are prefaced simply by the words "on one occasion" they give us no clue about the actual time they occurred. Put simply, the sutras record where, to whom and about what Sakyamuni spoke, but give us no information about "when".
Some events though are clear as and of themselves, such as the enlightenment and the entry into Nirvāna, and the biographical scriptures mentioned above have conveniently gathered these together as the Buddha's "Life". In other words, the early Buddhist scriptures comprise a vast amount of records about events in Sakyamuni's life, which simply lack a date. It is like having a great stack of undated photographs. But these photographs contain images of people and places. So for example if we see Tokyo Tower in a photo of the temple Zojoji, we know that the photo must have been taken after 1958, when the tower was built, and conversely if the tower is not there, it must date from before then.
Since each sūtra contains a mass of information, if we can analyse it, like unravelling the clues in a detective novel, we should at least be able to work out the chronological context, just as it is not impossible to determine a rough date for our photos if we know exactly when Tokyo Tower was built. We have in fact been able to ascertain some dates, for example the date of the ascension of King Aśoka and the year that the Bhikkhuni (Nuns') Saṃgha was formed, as announced in the monographs, and the date of King Pasenadi's conversion, as reported in our Proceedings.
If we can arrange the earliest Buddhist scriptures chronologically as far as possible, using clues afforded by the people appearing in them, the events that occurred, and their setting, we should be able to reconstruct the Buddha's life and to throw light on the individual biographies of the Buddha's followers, and have a clearer idea about how the Saṃgha was formed. For example, as the monographs show, a great deal has already come to light about the biographies of Māha Kassapa and Māhapajāpatī Gotamī.
In the course of the long history of Buddhist Studies, there must of course have been scholars to whose minds this methodology would have occurred. However, the size of the task must have made them quail, just as if we would if confronted with a mountain of ten thousand or so photographs to sort out. Luckily though, today we have the ability to sort through a vast mass of data by the means of the computer. In this sense, this research project has been enabled by the times. It began in 1992 with a number of researchers working together to enter data into the computer from a vast number of early Buddhist scriptures and commentaries. Since the first essay did not appear until 1999, data construction required seven years. In fact, data input has not yet been completed even now, and corrections are added on a daily basis. When this research is finished, we plan to upload this data, but there is no indication when this will finally happen.