The Perfection of Energy - The four supreme efforts

“And from what point of view, monks,

should the controlling faculty of viriya, energy, be regarded?

From that of the four supreme efforts.”
There are four supreme efforts (samma-ppadhana):
the effort to avoid the akusala dhammas which have not yet arisen the effort to overcome the akusala dhammas which have arisen the effort to develop kusala dhammas which have not yet arisen the effort to maintain kusala dhammas which have arisen, not to let them decline, to further develop them, to cause them to increase and to reach completion.
Viriya which is a faculty, indriya, and has become a “leader”, must have been accumulated very gradually so that it could become a faculty. The controlling faculty of viriya should be regarded from the point of view of the four supreme efforts.
We can notice ourselves whether we have viriya which only begins to develop and is still weak, or whether it is already right effort: the effort which avoids akusala not yet arisen, overcomes akusala already arisen, the effort to cause the arising of kusala which has not yet arisen. The kusala dhamma which has not yet arisen refers to samatha and vipassana and to the path, magga, the fruition, phala, the lokuttara cittas which experience nibbana. As to the words samatha and vipassana in this context, these refer to satipatthana. Samatha and vipassana are developed together and reach completion together by the four Applications of Mindfulness, they should not be separated from each other. Effort is necessary to maintain the kusala dhammas which have arisen, not to let them decline, further to develop them, to cause them to increase and reach completion.