I’d like to make a highly and crucially important point about this thread, since there seems to be posts made about it, with the implicit meaning that: “jhāna isn’t that important, even for the path of stream-entry/once-returner…” (or even “for the path as a whole”).
I’d like to make clear that my intention with this thread was, first, to clarify a common belief that “sammā-samādhi is simply the four jhānas,” as it is often described in the Suttas (there are multiple definitions of sammā-samādhi), and by some people. The issue with this (if it were true), is that, developing all aspects of the Eightfold Path is important, but if jhāna hasn’t been developed, then it would mean that such a person would in a way not be practicing all the eight parts of the Eightfold Path.
It is not true that sammā-samādhi is only the four jhānas. Even concentration developed from simply attempting to develop jhāna, is the development of higher levels of concentration, and of sammā-samādhi.
The second point, being the most important, has to do with that, although it is possible for one to reach sotāpattimagga/sakadāgāmimagga without jhāna, it is much more the case that it is unlikely. It in no way means that “jhāna isn’t needed,” it means that it’s simply not impossible for one to reach sotāpattimagga/sakadāgāmimagga without jhāna. In the same way that it’s not impossible to jump 2.4 meters (the highest jump in the world was done in 1993, and was of 2.45 meters). One could become a once-returner without jhāna, but it is unlikely.
Now, discouragement is the crux of the issue. In the same way that jumping 1m isn’t that difficult after some training, jhāna also isn’t as difficult as most make it out to be. And even if you don’t reach jhāna in one week, one month, or one year—you are still developing higher levels of concentration. Concentration/sammā-samādhi and jhāna is a spectrum, and jhāna is simply a form of concentration where there are certain aspects of the mind that are absent (five hindrances), and aspects of the mind (thought-conception/vitakka, discursive thinking/vicāra, rapture/pīti, pleasure/sukha) that are present—that’s all.
Again, jhāna is essential for the path. Even if you can’t attain yet, don’t give up, persist, and in a few weeks, months, or even a year if that is what is needed (of consistent meditation practice), you will be able to reach jhāna.
As with AN 4.162, there are four modes of progress:
Bhikkhus, there are these four modes of practice. What four?
(1) Practice that is painful with sluggish direct knowledge;
(2) Practice that is painful with quick direct knowledge;
(3) Practice that is pleasant with sluggish direct knowledge; and
(4) Practice that is pleasant with quick direct knowledge.
These are the four modes of practice.
Although the above sutta describes knowledge, concentration is a direct requirement and condition for the arising of wisdom/paññā. If there is no concentration, then there can be no wisdom/paññā. Therefore, the path without at least some higher levels concentration is a path that will be painful, or the worst of the four modes above (“(1) Practice that is painful with sluggish direct knowledge”).
To illustrate my point, as with the Suttas, a simile is helpful: the path without jhāna or higher levels of concentration, is like travelling the oceans on a small and broken-down raft; the path with higher and more developed levels of concentration is like navigating the oceans on a small motorboat; and the path with jhāna is like travelling any of the great oceans with a 30-foot well-built sailboat.
Develop jhāna, even if it takes months, or even one or multiple years (again, of consistent meditation practice). The path without jhāna is a painful one—and higher levels of concentration are needed to progress with one’s practice, and on the path.