For me, Jhana has a very wide meaning. I consider Sutta eight or nine Jhana’s are higher attainments. Even if we are not at such a higher level we still can have a taste of true Jhana. Right effort and right mindfulness is the gate way to higher Jhanas. So a person with the right effort and right mindfulness start to experience a some what lower level of Jhanas.
Sila is the foundation of Jhanas. So the person practice Sila also experience a certain level of Jhana.
This is my personal opinion, please share your experience.
I’m convinced by arguments suggesting that the four Buddhist jhanas - which use a “letting go” approach - are an innovation based on the basic samana jhanas being practiced around that time, all of which differ from the prevailing Brahmin practices. So, the formless attainments do not follow samatha (jhana) in a progression but are in fact a separate system of contemplative effort. Trying to splice the two together is a confuscation.
Another way of saying this is that basic samana samatha is basic samana jhana. Doctrinal specifications then get applied to this baseline. So, the application of Buddhist doctrine (as ‘vipassana’) to a basic samatha practice results in the Four Jhanas we’re used to seeing. The Buddha taught anapanasati as the preeminent method for accomplishing this combination of Buddhist innovations with existing contemplative techniques.
So, basic samatha results in basic jhana experience. Buddhist jhana shows up when generic samatha becomes informed by the Dhamma, which of course happens in varying degrees over time.
My concept of jhana is less broad when compared to the above.
As a baseline I think jhana is a specific attainment (samapatti) into a different state (‘of consciousness’), as a result of developing samadhi. Perhaps controversially, I believe both samatha and vipassana can lead to jhana, as Right concentration is a result of Right mindfulness, and the latter develops both. A couple of dry vipassana meditation teachers told me they developed jhana in their practice. It is very likely being ordained helped a lot with this.
Now most Pali terms have broad meanings, and there a few suttas referring to walking while in jhana etc. In this I believe (with no EBT proof) that this refers to a post jhanic blissful state, which can feel a lot like being in a jhana, but has exited the jhana.
Another subset, if you like, is retaining the ability to go into a jhana. I don’t think this is being in a ‘jhana’ per se, but is ‘valid’ as far as a constituent requirement for enlightenment.
Yes, you could say when observing the five precepts (reciting the formal pali stanza) there is something different from the ordinary day-to-day state of consciousness. However imagine climbing a small hill and feeling a difference up there and then comparing that to climbing mount Everest and the difference there. The small hill would be reciting the pali stanzas and mount Everest would be the first jhana. The effort and also the rewards are far greater.