In the initial stage, the main part is played by the 1st jhanic factor – initial application of mind (vitakka), the mental factor that lifts the mind and mental states to its object. In metta bhavana, it is the continuous bringing up of Metta consciousness to its object – the person selected.

So when metta keeps flowing up we always make sure that we have the same person in mind. This part is concentration. Very often the mind will flit to other persons and if so, we can just let the metta flow on for a few seconds and return to the original one. Sometimes the new person seems to arouse stronger feelings than the original one intended and so we may be tempted to switch objects. It is best to return to the original one as there will always seem to be a better one when the original becomes somewhat stale. The test is the ability to go on with the same one for a long time.

Another problem involved at this stage is visualisation. Some practitioners may visualise the object, i.e. the person. This may be a help in some ways or it may also cause complications. The problem may arise with unmindful visualisations which can cause tension and stress over a period of time. Presently there are already two processes to take care of:

(1) Metta
(2) Concentration

Visualisation may come as a third process although connected with the second. One has to be careful not to visualise without metta or even mindfulness.

As the arousing by initial application predominates the first part of the concentration exercises, the next step is the sustained application (vicara) which is sustaining the metta consciousness continuously onto its object. This can be seen as dragging or lengthening the flow of Metta which would otherwise stop. In fact it is a product of continuous arousing. As a result, the momentum of the flow is built up. It continues even after one does not intend to radiate Metta, and if one does, a minimal effort is needed. Therefore one has to try to drag on each aspiration as long as possible so that the metta is continuously flowing onto the person for a long time.

When this can be done, usually joy (píti) follows. The progress thus acquired removes sceptical doubts and brings calmness. Joy is a thrilled, joyful state of mind that comes with increasing concentration. Sometimes it comes with goose pimples or pleasantness (minor joy). It may come in flashes or sudden rushes of coolness (momentary joy), or it may make one feel lighter or hop or jump (uplifting joy), or one may feel overwhelmed in wave-like, joyful feelings and sway (overwhelming joy), or one feels the entire body and mind system suffused to every single particle with joy and comfort (suffusing joy).

It is certainly very pleasant and attractive when one first comes across these. In metta bhavana they can be abundant. The usual tendency is to become attached to them. As a result mindfulness is lost. Then complications arise. So when they become very strong one would have to keep them under control. One will have to keep up the mindfulness and note. If one's body starts swaying or tears start to fall uncontrollably, one would know that it has gone too far and one should wilfully stop it or get up. Then we should bear in mind that when the strong joy and emotions tend to be overwhelming, to ensure that the metta is truly unselfish, the mind can be kept detached as we radiate very softly and gently with mindfulness rather than in an intense manner. If we keep on radiating in this way the joy will become very subtle and tranquil. The mind will experience deep bliss (sukha) within or as if a very high and rapturous state. Again one must be guarded against attachment so that one can continue one's practice.

The final stage will be the sinking in, absorption or unification with the object. This is one-pointedness. Again there must be some mindfulness at the very quiet and still stage before absorption. Otherwise one may lapse into deep sleep or is pulled away by subtle thoughts. At this last phase, the Visuddimagga quotes joy as overcoming restlessness, bliss as overcoming ill-will, and one-pointedness as overcoming sensual desires because it stops the mind from flitting to sense objects and fixes onto the meditation object.

Hence the five jhanic factors are:

1. Initial application (vitakka)
2. Sustained application (vicara)
3. Joy (píti)
4. Happiness (sukha)
5. One-pointedness (ekaggata)

In practice, these factors can be defined as follows:

1. Bringing the mind to the object (arousing, applying)
2. Keeping the mind with the object (sustaining, stretching)
3. Finding, having interest in the object (joy)
4. Being happy and content with the object (happiness)
5. Unifying the mind with the object (fixing).