Yes they did, in order to address problems that you recognised on the CT site the other day. Problems that I think we both know Theravāda, at least Classically, can’t answer. Anyway, regardless of their view on time the Sarvāstivādins claimed that arising, persiting and ceasing were real. They did so because according to them and Theravāda there are either real existents or concepts. Real existence have an intrinsic, mind-independent essence whilst concepts do not. If then arising, persisting and ceasing have no sabhāva then they aren’t real. Dependent arising then wouldn’t occur, and you would be left with a plurality of static dhammas. So, they made these things real. Of course this leads to its own absurdities. Theravāda on the other hand just side-lines the issue.
We are, of course, talking about a conventional existence, a processual one, which is opposed to absence, or the perception of the opposite. By saying that fire exists, we deny the presence of water in this very place or the presence of emptiness, an empty place in this very place. Which, however, does not endow fire with some absolute existence, a substantial existence, or existence in the three times. You are making a mistake similar to the Mahayana. They grew out of criticism of the extremes of substantialism of some schools. And in order not to lose the meaning of their existence as a philosophy built entirely on denial, they deny any hint of the existence of dhammas, even simply as temporary impersonal properties. That is, they assign to the opponent exaggerated hyperbolic statements about existence.
The issue the Prajñāpāramitā had was with the essence or substance based thinking of the Abhidharmas that were floating around. That applied as much to Theravāda as to Sarvāstivāda. What is denied is that there is any essence or substance in dhammas, so a mind-independent reality to them. The dhammas are still there, but they are illusion or dream like.
Buddha, however, did not hesitate to affirm that impermanent aggregates exist and that the wise consider them to exist (that is, present in nature, in contrast to the permanent ones, which do not exist at all and are not real). In the same way we can say about the presence of the cessation of defilements/formation. It is real, it is not nothing, since nothing would be the negation of the cessation itself and either an irrational and allological amorphous nothing, or the return of samsara, as I indicated above.
The Buddha was fine with saying the aggregates exists and then cease, sure. He was also fine with saying there is a self on occasions. Thinking though the aggregates are real, mind-independent things is not only contradictory (a dependent thing can’t also be independent) but is the basis for the theories of Eternalism and Annihilationism. To say there is something and it always is is the Former. To say there is something and it is eventually destroyed is the latter. In order to be an Annihilationist, for example, you have to think something is real and independent in order to be the basis for the self. The Buddha was responding to essence or substance base thinking, the very thing the Ābhidhammikas then adopted. Now when you say cessation is real you would have to say the cessation of cessation is also real, leading to an infinite regress. This was the problem Theravāda had with Sarvāstivāda, the “arising of arising”. You are also essentially saying that “stop” exists when you say “cease” exists. That behind the concept “cease” there is a real thing called cease. This make as much sense as saying “go” really exists. Yes we can say there is an absence of this or that, but only conceptually. There is no referent for the idea. Just like the word “go”, the word “cease” is just a concept we apply to a certain set of conditions.
For something to be real and existent, it does not need to be given some vague philosophical essence like sabhava. Incidentally, it is nowhere to be found in the suttas. More ordinary, human language is used there.
I was using language a Classical Theravādin like yourself would be familiar with. I agree that sabhāva isn’t found in the suttas. Essence and substance based thinking is though. That is after all what the atta the Buddha’s opponents were proposing was. In ordinary language we can just say independent existence. That is how ordinary people speak when they want to say something is real. It exists independently of mind.
This is similar to the Mahayana idea of emptiness, which, by denying dharmas, asserts that being has never left nirvana-shunya, there is no origin, therefore there is no change and cessation. No Suffering, No Cause, No Cessation, No Path. Whoever sees this way has already reached the goal and, as it were, escaped from samsara without leaving it. This is purely a mental construct.
I accept certain teachings from Mahāyāna, yes (I don’t accept the Bodhisattva idea). Nibbāna isn’t an eternal something, nor is it an eternal nothingness. Nibbāna is just a term for when we stop thinking in that way. When you see the dependent arising of sense experience you see the empty nature of all dhammas. Since dhammas are empty of substance or essence, the ontological categories of Existence (Eternalism), Non-Existence (Annihilationism), Both Existence and Non-Existence (Jainism) or Neither Existence nor Non-Existence (Vedic) no longer apply.
In reality, phenomena are neither absolutely existing nor absolutely non-existent. The truth is somewhere in the middle. Seeing them as absolutely existing is a construct of the mind, a formation of the mind. It is impermanent, and one cannot rely on it. Seeing them as absolutely non-existent, unarisen, nirvanic in nature, that is, equal to the great Shunya - is also a construct of the mind. It will also exist, and then fall apart. And one cannot rely on this either.
The dhammas exist conventionally. To put it another way we have sense experience, this can’t be denied, but we can’t establish if that experience is ultimately real or not-real. We can’t say its ultimately real because of its dependent nature. We can’t say its ultimately non-existent because we experience it.
But for one who sees the origin of the world as it really is with correct wisdom, there is no notion of nonexistence in regard to the world. And for one who sees the cessation of the world as it really is with correct wisdom, there is no notion of existence in regard to the world.
