Samatha - One must understand factors and conditions
From the foregoing examples we see that samatha cannot be cultivated without a basic understanding of the realities taught in the Abhidhamma which are in fact the realities of daily life, and without careful consideration of them. One should know precisely when the citta is kusala citta and when it is akusala citta. One should know which realities the jhāna-factors are and one should realize as regards oneself whether the jhāna-factors are developed or not. One should know whether the cetasikas which are the five indriyas (faculties) are developed or not, whether they are balanced or not. If there is not the right understanding of all these different factors and conditions necessary for the attainment of 'access concentration' and of jhāna, one is in danger of taking for 'access concentration' what is not 'access concentration' and taking for jhana what is not jhāna. Neither 'access concentration' nor jhana can be attained without having cultivated the right conditions.
Not all meditation subjects lead to jhāna, some have only 'access
concentration' as their result, such as the recollections of the Buddha, the
Dhamma and the Sangha. Some meditation subjects lead only to the first
stage of rūpa-jhāna, some to all stages of rūpa-jhāna. The meditation subject
which is 'mindfulness of breathing' can lead to all stages of rūpa-jhāna.
This meditation subject which is considered by many to be relatively easy, is
one of the most difficult. One has to be mindful of one's in-breath and out-
breath where they touch the tip of the nose or the upper-lip. This meditation
subject is not learnt by sight, but by touch : the in-breath and the out-breath
are the 'sign' (nimitta) one has to continue one's attention to. We read in the
'Visuddhimagga' (VIII, 208):
'For while other meditation subjects become clearer at each higher stage, this
one does not: in fact, as he goes on developing it, it becomes more subtle
for him at each higher stage, and it even comes to the point at which it is no
longer manifest.'
Further on (Vlll, 210, 211) we read:
'... This was why the Blessed One said: 'Bhikkhus, I do not say of one who is
forgetful, who is not fully aware, (that he practises) development of
mindfulness of breathing.' (Middle Length Sayings III, No. 118, 84)
'Although any meditation subject, no matter what, is successful only in
one who is mindful and fully aware, yet any meditation subject other than this
one gets more evident as he goes on giving it his attention.
But this mindfulness of breathing is difficult, difficult to develop, a field in
which only the minds of Buddhas, Pacceka Buddhas, and Buddhas' sons are
at home. It is no trivial matter, nor can it be cultivated by trivial persons. In
proportion as continued attention is given to it becomes more peaceful and
more subtle. So strong mindfulness and understanding are necessary here.'