Hello Stephen and any others interested in such obscurities,
A while ago you said that it has been convincingly argues that the
Mula Sarv are the same as the Sautrantika. I still haven't seen any
convincing evidence that this is so, and in the meantime have
thought of a few objections to this idea.
First is that the sautrantikas were characterized as 'anityavadins'.
They strongly stressed impermanence, rejected the main Sarvastivada
theory of the existence of dhammas in the three times, and developed
a new 'two anukkhana' version of the khanavada. That is, each mind-
moment can be divided into arising and ceasing, whereas for the
Sarvastivada it is arising, persisting, decaying, ceasing.
(Incidentally, The origins of this theory can be traced back to the
Sarvastivada Nidana Samyukta. Where the Ther says that the
conditioned things are characterized by arising, change while
persisting, and ceasing, the cognate sarv passage has arising,
persisting, decay, cease.)
How can the Sautrantikas be part of the Sarvastivada if they
strongly rejected the central theory of the school?
The second point is that the Mula Sarv vinaya has Maha Kassapa
reciting the matika at the first council. How could a school such as
the Sautrantika, whose chief tenet was to insist on the sole
validity of the suttas as Buddhavacana, authorize the Abhidhamma in
such a way?