Calm is not the same as concentration
We read in the suttas about monks who developed both calm and insight, but we should not conclude that we all must develop jhana. Many people who came to see the Buddha were used to developing samatha already and the Buddha exhorted them to develop vipassana as well so that defilements could be eradicated. If monks in the Buddha’s time had accumulated conditions for jhana, jhanacittas could arise. If they did not cling to jhana there could be right understanding of jhana as only a conditioned reality, not self.
Is it necessary to develop mindfulness of breathing so that there can be later on mindfulness of any nama or rupa which appears? This is a question which is often asked.
Mindfulness of breathing is a subject of samatha and it is also included in “Mindfulness of the Body” which is one of the “four Applications of Mindfulness”. If one wants to develop mindfulness of breathing as an object of calm one should know that this is one of the most difficult subjects of samatha. It can easily be an object of clinging instead of an object of calm.
Calm is not the same as concentration. We should remember that concentration is a cetasika that accompanies each citta and that can, therefore, arise with kusala citta as well as with akusala citta. When akusala citta with clinging arises there is wrong concentration, there cannot be right concentration. When the feeling is indifferent one may think that there is calm, but, as we have seen, there can be clinging accompanied by indifferent feeling. People who apply themselves to yoga may concentrate on breath for reasons of health or relaxation. One may benefit from yoga in different ways, but one should know that the aim of samatha is temporary freedom from defilements. In samatha right understanding of the way how to develop calm is indispensable, it is not sufficient to know in theory that we have a great deal of clinging. We have to find out whether there is at this moment clinging, even if it is subtle. We should be honest with ourselves. If we do not know whether the citta at this moment is kusala citta or akusala citta there cannot be development of calm. The test is always at this moment.