i wrote this letter sbout 10 years ago to someone who believes that later monks added in the theory of momentariness to the Dhamma.
In the 'Greater Discourse on the Destruction of Craving' (Mahatankhasankhaya-sutta, majjhima Nikaya I, Mahayamaka-vagga):
It is because, monks, an appropriate condition arises that consciousness is known by this or that name: if consciousness is know by this or that name: if consciousness arises because of eye and material shapes, it is known as seeing-consciousness; if consciousness arises because of ear and sounds it is known as hearing-consciousness; if consciousness arises because of nose and smells, it is known as smelling-consciousness; if consciousness arises because of tongue and tastes, it is known as tasting- consciousness; if consciousness arises because of body and touches, it is known as tactile-consciousness; if consciousness arises because of mind and mental objects, it is known as mental consciousness.
Ya~n~nadeva1 bhikkhave paccaya.m pa.ticca uppajjati vi~n~naa.na.m tena teneva sa"nkha.m gacchati: cakkhu~nca pa.ticca ruupe ca uppajjati vi~n~naa.na.m, cakkhuvi~n~naa.nanteva sa"nkha.m gacchati. Sota~nca pa.ticca sadde ca uppajjati vi~n~naa.na.m, sotavi~n~naa.nanteva sa"nkha.m gacchati. Ghaana~nca pa.ticca gandhe ca uppajjati vi~n~naa.na.m, ghaanavi~n~naa.nanteva sa"nkha.m gacchati, jivha~nca pa.ticca rase ca uppajjati vi~n~naa.na.m, jivhaavi~n~naa.nanteva sa"nkha.m gacchati. Kaaya~nca pa.ticca pho.t.thabbe ca uppajjati vi~n~naa.na.m, kaayavi~n~naa.nantevasa"nkha.m gacchati. Mana~nca pa.ticca dhamme ca uppajjati vi~n~naa.na.m, manovi~n~naa.nanteva sa"nkha.m gacchati
in the suttas the Buddha was very careful to help people to see that each moment is different from the last. The eye-consciousness has different conditions than the ear consciousness. Someone, before they heard the teaching, might imagine that the same consciousness lasts and could take two or three objects at about the same time. But it can be seen that this is not so.
The sutta continues:
Monks, as a fire burns because of this or that appropriate condition, by that it is known: if a fire burns because of sticks, it is known as a stick-fire; and if a fire burns because of chips, it is known as a chip-fire; and if a fire burns because of grass, it is known as a grass-fire; and if a fire burns because of cowdung, it is known as a cowdung-fire ... Even so, monks, when because of a condition appropriate to it consciousness arises, it is known by this or that name
The commentaries stress this so much more. They explain that in the time it takes to snap a finger ..kotis of mindmoments have arisen and passed, each one not the same but conditioned by different conditions, and none of these conditions is exactly the same either.
Take a moment of seeing: For seeing to arise there must be cakkhu pasada (seeing base). This is the extremely refined rupa that arises in the center of the eye. This special rupa is the result of kamma. reason we can keep seeing is that at this moment the force of the kamma is still working to continue replacing the cakkhu pasada. The visible eye, the eyeball, and the surrounding matter, the rest of the body, are also conditioned by different conditions - not only kamma- and these rupas also only last for a moment before vanishing forever. Every conditioning factor is simarly evanescent as is every conditioned moment.
Your book by Mr. Sarachchandra, says " the Theory of moments was introduced into Abhidhamma around the twelfth century - Early Buddists texts reflect a doctrine of momentariness rather than a theory of moments - By the time of the third council, the doctrine of momentariness was common between all schools with minor technical variations; for example, the "Points of Controversy" discusses if a "moment" of consciousness lasts a whole day. Rupa was described as having two phases (nascent and cessant); the theory of moments later added the static phase."""
This 'static' phase is far from static according to the Theravada commentaries, and also the later tikas. For example The Dispeller (page 37)
ndeed feeling also arises and falls and has no length of duration. In the moment of one snapping of the fingers it arises and ceases to the number of one hundred thousand kotis
Note that vedana (feeling) arises and passes together with consciousness and all other mental elements.Any wordswe use to describe the nature of realities - impermanent, momentary, temporary, instant by instant- cannot convey the actual rapidity of the arising and passing away. But to explain the dhamma it is useful to use such words as 'moments' when ,say, explaining the difference between a moment of seeing and a moment of hearing.
In the Patthana - the last book of the Abhidhamma , the importance of which is greatly stressed in the commentaries and Abhidhammathasangaha is all about conditions. Here we learn that "moments" are extraordinarily complex instants in time with influences from past and present factors. The dhammas themselves are not different from the quality they posses. In fact the Atthasalini says that "there is no other thing than the quality born by it". And no moment is identical with another. It is true that such dhammas as sa~n~na (perception) or vedana (feeling) or vi~n~nana (consciouness) are classified under the same heading but the actual quality is influenced by so many diverse factiors that not even one moment of feeling is exactly the same. Also because similar conditions arise repeatedly nor are succeeding moments totally different. The same feeling can appear [and I stress appear] to last for seconds because of this. The Abhidhamma allows us to understad that this is illusion and to learn to study directly the present moment so that eventually this idea of permenance is broken.
You wrote that "Anuruddha [author of the Abhidhammasangaha which SarathW quoted earlier in this thread] added material reflecting ideas that were current at his time." I don't think so. He put, in a simple way, what was already well rehearsed by generations of great monks from the time of the Buddha. Although sometimes the commentaries added extra useful material a great deal of them came from the time of the Buddha. The Atthakattha to the Dhammasangani (first book of the Abhidhamma) the Atthasalini: from the introductory discourse "The ancient commentary therof was sang By the First council, Mahakassapa Their leader, and later again by seers,
13. Yaa Mahaakassapaadiihi vaasiih'a.t.thakathaa puraa sa"ngiitaa anusa"ngiitaa pacchaa pi ca isiihi yaa
It then says:
Mahinda bought it to the peerless isle, Ceylon,..