The Buddha talked about that there are only 12 āyatana and no more.
The 4 arūpa states (base of infinite space, consciousness, nothingness,neither perception nor non perception) are āyatanas:
- ākāsānañcāyatana
viññāṇañcāyatana
ākiñcaññāyatana
nevasaññānāsaññāyatana
2) Why aren't 4 jhāna considered to be āyatana? What is the significance of that? It seems like there is some form of qualitative or fundamental difference between them.
Thanks