And what is inquiry that’s too lax? It’s when inquiry is coupled with laziness. This is called lax inquiry.

And what is inquiry that’s too tense? It’s when inquiry is coupled with restlessness. This is called tense inquiry.

And what is inquiry that’s constricted internally? It’s when inquiry is coupled with dullness and drowsiness. This is called inquiry constricted internally.

And what is inquiry that’s scattered externally? It’s when inquiry is frequently scattered and diffused externally on account of the five kinds of sensual stimulation. This is called inquiry scattered externally. … That’s how, with an open and unenveloped heart, a mendicant develops a mind that’s full of radiance. When the four bases of psychic power have been developed and cultivated in this way they’re very fruitful and beneficial.