Eight Levels of Concentration
With further practice the factors of concentration gain in strength and bring the mind to absorption (appana-samadhi). Like access concentration, absorption takes the counterpart sign as object. The two stages of concentration are differentiated neither by the absence of the hindrances nor by the counterpart sign as object; these are common to both. What differentiates them is the strength of the jhana factors. In access concentration the jhana factors are present, but they lack strength and steadiness. Thus the mind in this stage is compared to a child who has just learned to walk: he takes a few steps, falls down, gets up, walks some more, and again falls down. But the mind in absorption is like a man who wants to walk: he just gets up and walks straight ahead without hesitation.
Concentration in the stage of absorption is divided into eight levels, each marked by greater depth, purity, and subtlety than its predecessor.
The first four form a set called the four jhanas, a word best left untranslated for lack of a suitable equivalent, though it can be loosely rendered “meditative absorption.”
The second four also form a set, the four immaterial states (aruppa). The eight have to be attained in progressive order, the achievement of any later level being dependent on the mastery of the immediately preceding level.
The four jhanas make up the usual textual definition of right concentration. Thus the Buddha says:
And what, monks, is right concentration? Herein, secluded from sense pleasures, secluded from unwholesome states, a monk enters and dwells in the first jhana, which is accompanied by initial and sustained application of mind and filled with rapture and happiness born of seclusion.
Then, with the subsiding of initial and sustained application of mind, by gaining inner confidence and mental unification, he enters and dwells in the second jhana, which is free from initial and sustained application but is filled with rapture and happiness born of concentration.
With the fading out of rapture, he dwells in equanimity, mindful and clearly comprehending; and he experiences in his own person that bliss of which the noble ones say: “Happily lives he who is equanimous and mindful” — thus he enters and dwells in the third jhana.
With the abandoning of pleasure and pain and with the previous disappearance of joy and grief, he enters and dwells in the fourth jhana, which has neither-pleasure-nor-pain and purity of mindfulness due to equanimity.
This, monks, is right concentration.