Hi Venerable,
I’ve also been interested in the sources of the various interpretations of DO, especially the moment to moment interpretation. I’ve been puzzled by the claim that this interpretation can be traced to the Vibhaṅga of the Theravada Abhidhamma. Here is the passage that is sometimes referred to:
Tattha katamā bhavapaccayā jāti? Yā tesaṃ tesaṃ dhammānaṃ jāti sañjāti nibbatti abhinibbatti pātubhāvo – ayaṃ vuccati “bhavapaccayā jāti”.
In this case, what is “existence is the condition for birth”? That which is the birth, being born, coming forth, coming into being, manifestation of those various things: this is said to be “existence is the condition for birth”.
“Those various things”, tesaṁ tesaṁ dhammānaṁ, presumably refers back to the four mental aggreagtes (khandhas) mentioned in the immediately preceding definition of existence (bhava). Here is that definition:
Tattha katamo upādānapaccayā bhavo? Ṭhapetvā upādānaṃ, vedanākkhandho saññākkhandho saṅkhārakkhandho viññāṇakkhandho – ayaṃ vuccati “upādānapaccayā bhavo”.
In this case, what is “taking up is the condition for existence”? Apart for the taking up, it is the feeling aggregate, the perception aggregate, the will aggregate, the consciousness aggregate: this is said to be “taking up is the condition for existence”.
The moment to moment proponents then argued that because bhava is defined as the four mental khandhas this must refer to the moment by moment arising of mental phenomena.
It is interesting, of course, that the Abhidhamma leaves out rūpakkhandha, and this certainly needs to be explained. Yet the broader context suggests that this, too, is about rebirth. The words used in the Abhidhamma are essentially the same as those used for rebirth in the standard sutta explanation of DO. Here is a comparison of the two definitions of jāti, starting with the sutta definition:
Jāti sañjāti okkanti abhinibbatti, khandhānaṃ pātubhāvo, āyatanānaṃ paṭilābho.
Jāti sañjāti nibbatti abhinibbatti pātubhāvo.
The two are obviously closely related. If the sutta definition relates to rebirth, it is hard to see why the Abhidhamma definition would be seen differently. But again, the differences need to be explained.
So why might rūpakkhandha, “the form aggregate”, be missing from the Abhidhamma definition of bhava? We know that the Abhidhamma is essentially about classifying and relating the constituents of reality to each other. To make DO universally applicable is makes sense to take out rūpa (perhaps it should be regarded as subsumed under one of the other factors, such as saññā), thereby including all the realms of existence, also the arūpa realms, into its formulation. I think this is at least a plausible reason for the unusual formulation. There may also be others.
It’s important to note here that also the other factors of DO, as defined in the Abhidhamma, have had the rūpa element removed. So we find nāma instead of nāmarūpa and chaṭṭhāyatana (“the sixth sense base”, that is, the mind) instead of saḷāyatana (“the six sense bases”). And I think this is also the explanation for the difference in the definition of jāti. The Abhidhamma definition leaves out precisely those terms that involve rūpa, that is, okkanti, khandhānaṁ (pātubhāvo), āyatanānaṁ paṭilābho (In the suttas okkanti or avakkanti is often related to nāmarūpa.) And I think the same argument can be made for old age and death, for which, again, the rūpa aspect seems to be left out. (Indeed, this how the commentary explains it.)
In sum, without having delved into all the details, it seems to me that there is no particularly good reason to think that the Abhidhamma teaches some kind of moment to moment DO. If this is correct, it seems likely that this is entirely a modern phenomenon. This may not have been the question your were asking, @Vaddha, yet it may still be illuminating in its own way. It looks likely to me that the moment to moment interpretation is a modern projection onto the suttas. In other words, it is the result of a cultural bias coming from societies where the idea of rebirth is often questioned, if not outrightly dismissed. This gives a good foundation for understanding why such ideas have arisen. Moreover, it is a good reminder of how easy it is to backread our own biases into the suttas.