firewns:
You state: ‘ Even if they(Sot. and Sot. Anug’s) attain a deva bhava, they may still go back to a human bhava at the end of the deva bhava, or attain nirvana in the deva realms.’ (Does it necessarily follow that since ‘they attain a deva bhava’ they automatically become Sakadagamis on getting there, or have they got to work towards that in theirSotapanna/Sotapanna Anugami stage?) This may sound confusing; if so, just pass it by.
First of all, if they are still attached to gross-material existence,and that overwhelms any deva bhava they may have developed to whatever (minor) degree, PS would work in that direction; i.e. towards a human bhava. I cannot, at least for now, see how it can be otherwise. And..if that were so,that is, that they can indeed attain a deva bhava, then that will not be consistent with either: ‘When one attains the Sakadāgami stage by REDUCING kāma rāga and patigha, one will be forever released from the human realm and one could be born only in dēva realms of the kāma lōka.'(Seeking-nibbana/dasa-samyojana-bonds-in-rebirth-process #17) or with reason. The Sakadagami stage SPECIFICALLY is mentioned as the one through which the human stage is transcended- though I leave myself open to more light that may be shed on the matter through further reading and contemplation.
Note that the above quote from the post does not specify whether that Sakadagami stage is attained in the human or a deva realm. I am apt to think that it is refering to the attainment of the Sakadagami stage when in the human realm. Further I have reflected for long on what could be the reason or reasons that a Sakadagami ‘descends’ to the human realm when he/she could strive to attain a higher bhava or Nibbana itself from there. Two that came to mind were:
1) He/she realizes that he/she cannot strive for a higher magga phala or Nibbana because for that he /she would have to learn a lesson or lessons he had neglected when in former human bhavas, and the deva realm to which he belongs no longer afford such ‘elementary’ lessons – like when, for instance, you intend to build a telescope and recall that you had neglected the light section in physics when you were in secondary school. Now you must dig into those lessons again, otherwise you are stuck.
2) The motivation to ‘clear debts’ with those still in a human body. These will be those you know you were connected with in the past and who you wish to ‘help on’. It may be likened to someone who leaves the comforts of home and undertakes a tiresome journey to find a friend and get him/her out of distress.
I could go on, but will be content for now with your remarks on this much.