Function of Javana - Dwelling heedless

There are countless javana-cittas in a day with lobha, dosa and moha, and therefore we should not be heedless, but we should be as mindful as we are able to. We read in the 'Kindred Sayings' (IV, Salāyatana-vagga, Kindred Sayings on Sense, Second Fifty, par. 97, Dwelling heedless) :

At Savatthi was the occasion (of this discourse)...

'I will teach you, monks, of the one who dwells heedless,

and of the one who dwells earnest. Do you listen to it.

And  how, monks, does one dwell heedless?

 

In him, monks, who dwells with the faculty of sight uncontrolled, the heart is

corrupted by objects cognizable by the eye. In him whose heart is corrupted

there is no delight. Without delight there is no joy. Where joy is not, there is

no calm. Without calm one dwells in sorrow. The sorrowful man's heart is not

composed. When the heart is not composed, one has not clear ideas.

Through not having clear ideas he is reckoned as one who dwells heedless.

(And it is the same with regard to the faculties of taste, touch and mind).

 

And how, monks, does one dwell in earnest?

 

In him, monks, who dwells with the faculty of sight controlled the heart is not

corrupted by objects cognizable by the eye. In him whose heart is not

corrupted delight is born. In one delighted joy is born. When one is joyful the

body is calmed. He whose body is calmed feels at ease. Composed is the

heart of him who is at ease. When the heart is composed one's ideas are

clear. Through having clear ideas one is reckoned as one who dwells earnest.

(And it is the same with regard to the faculty of taste, touch and mind.)

Thus, monks, is one a dweller in earnestness.'