Hi Shaun
I have tried to explain how I see this in other posts on this forum.
Firstly I disagree with the translation of anattā as ‘not/non/no self’. For me, attā is the Pāli equivalent of Sanskrit atmā, which certainly means ‘soul’ and I think the Buddha would have used ‘anaham’ to mean ‘not self’, but I have not found it in the Pāli texts.
There is a place in the suttas, https://suttacentral.net/en/mn2#7, where doubt about one’s existence is said to be an obstacle of progress. There doubting the existence of self – ahaṃ (‘Am I/Do I exist?’ - ‘ahaṃ nu khosmi?’ and ‘Am I not/Do I not exist’ - ‘No nu khosmi?’) is said to be unwise reflection and leads to various wrong views about soul – attā (‘Atthi me attā’ti’, or ‘Natthi me attā’ti’). Some may think that means one has to have faith that one does not really exist. I think it simply means, one has gone off track in the question ‘to be or not to be’.
I think the Buddha accepts the existence of the Five Aggregates, but they are conditioned and impermanent. I equate them with an impermanent self that everyone has. The goal, for me, is ending the Five Clinging Aggregates, (which I translate to one word as ‘ego’, not ‘self’), that is, suffering, and once they are eradicated one just has an impermanent self that one knows as such (as it really is).
It is not the Five Aggregates (an impermanent self) that one has to end, imo. But I understand that is assumed from the first part of the definition of suffering, that is, the First Noble Truth, because it speaks of birth, aging and death. These are taken to be physical, but there is evidence in the Pāli texts that the Buddha used them spiritually.
I follow the summary sentence of the First Noble Truth, ‘that is, in brief the five CLINGING aggregates are suffering’. For me that summarises what had been said before and points to not assuming what he had just been spoken of was the Five Aggregates (without clinging).
Secondly I disagree with the translations of the first of the three knowledges the Buddha said he developed on the night of his enlightenment. It is there that the ideas of ‘past lives’ comes in. That would be ‘pubbe-jīvam’ in Pāli, but that is also not found in the Pāli texts. In that paragraph the Buddha talks of many past births, not lives. For me each birth is the arising of ego (the five clinging aggregates) in this very life.
For me there is no RE-birth as that suggests there is something personal going from one birth to another. Since I understand each birth is the birth of (an) ego (identity) in this very life, each one is different. For example, at one time I identified with certain beliefs and called myself ‘Christian’ after some time, I (ego) stopped doing that (died as a Christian) and was born ‘a Buddhist’. Both involve clinging and are suffering, imo. Instead I could just recognise my belief as belief and not cling to it as the truth and try to label myself by it.
This is the only way I have found to understand the Buddha’s teaching so that it is relevant to ‘this very life’ that he is recorded to have said often.
best wishes