(21) How Jhana is achieved
When this upacara-sarnadhi becomes strong and keen, the mind will dwell fixedly on the recipient of metta if it is drifting and floating along the stream of sensations in a dream. However, the mind may stay on only for a moment in the first instance. When continuous development of mindfulness on metta is further carried on, it may stay put on the sense-object for a duration of one minute or more, up to even one hour or so.
When thus, absorbed in mindfulness of metta despite the environmental effects of sensational objects, the mind does not make short flights to these sensations but will remain firm, stable and gets implanted on the person who receives the metta wishing him happiness. Rapturous feeling will also become conspicuous. Vitakka and vicara, reflection on the mind and investigation of what is going on with a bent towards the recipient of metta will become strengthened and obvious. The whole body will become evidently buoyant, light and comfortable. The stabilised mind becomes tranquil without going astray. This tranquillity of the mind (ekaggata) with particularly obvious manifestations of vitakka, vicara, piti and sukha is part and parcel of the noble attributes of the first jhana. All these noble qualities are called the first jhana. If such an achievement is derived, it is the attainment of first jhana. This is the reason why the Visuddhimagga has said that such a person can attain appanajhana even while developing metta using the expression - "Evarupe ca puggale kamam appana sampajjati."
This first jhana having imbibed or included the attributes of vitakka which reflects on the sensation, and of vicara which investigates into the nature of sensation, is not as strong and vigorous as it should be. Even in the course of absorption in jhana, if harsh sounds and shrill voices strike the ear-base of the sensation of hearing, the mind-consciousness may rise from jhana -and then reaches the sound which is the sense-object. That is why metta should be repeatedly developed towards the person on whom the mind is usually made to dwell, to create the tranquil "Jhanic-mind" without inclusion of vitakka and vicara. When samadhi gets strengthened extreme joy or rapture together with the calmness of the mind which are far more increasingly better, will occur without making effort to let the mind inclined and reflected towards the sensation, and also without making investigation into that sensation. This is the achievement of second jhana. At the moment of absorption in a trance of that jhana, intense delight or ecstasy is of the highest degree. If this extremely rapturous feeling - piti is not desirable, continuous development and transmission of metta should be made towards the usual recipient of metta, When concentration gets fully developed and strengthened, excellent mental happiness and tranquillity of mind without rapture (piti) will become obvious. That is the third jhana. This jhana is the most. exalted or the highest jhana among metta-jhana.
Either after achieving the jhana just mentioned, or, before achievement of that jhana, if it is desirable to develop metta equally balanced towards all beings, it may be developed and radiated on the most affectionate person as "may such one be happy, etc." It would be much better to develop and transmit metta after the attainment of jhana rather than before the attainment. Purified form of metta can occur easily. Hence, after metta-jhana has been achieved in respect of the most affectionate person, development of metta may be made directing towards, or in favour of a neutral person. After such an achievement of jhana for the sake of a neutral person, metta may be developed and bestowed upon a person who is an enemy, if there is any. In radiating metta towards different recipients one after another, different kinds of feeling or mental consciousness of metta should be developed only after firm and gentle mind has been brought about and cherished. This is what the Visuddhimagga has stated.
The statement that the mind or mental consciousness has been brought about to become or and gentle, in fact, refers to the acquirement of upacara-samadhi in the least. The best method is to change the course of developing metta only after achieving the jhana. Of all the various expressions, the statement: "Metta should be developed towards any enemy" is intended for the Yogi who has an enemy. Therefore, from the very outset, I have stated as: "... a person who is an enemy, if there is any." A Yogi, if he has no enemy, should not bother about the enemy in developing metta after he has developed loving-kindness towards a neutral person.
Anger is likely to occur, remembering the wrong done by a person who is an enemy, while a Yogi is developing metta towards him. When such an incident happens, metta-jhana which has been previously achieved in respect of any other person beforehand may be recalled and repeatedly plunged in; and then, by developing metta towards this particular enemy after rousing up, off and on, from the mental state of absorption in jhana, he should dispel or extinguish the fiery anger. In regard to those expressions, since the Visuddhimagga has stated as: "Mettam samapajjitva vutthahitva", it is clear. enough that metta-jhana has been attained in respect of other person except the enemy. Hence, I have stated that developing metta by shifting on to another after attainment of jhana in respect of the former person, is the best.