"At such times, monks, as the mind is sluggish, that is the wrong time to cultivate the enlightenment-factor [1] of tranquillity, the enlightenment-factor of concentration, the enlightenment-factor of equanimity. What is the reason? A sluggish mind is hard to arouse by these factors.

"Suppose a man wants to make a small fire blaze. If he heaps wet grass, wet cow-dung and wet sticks on it, if he exposes it to wind and rain and sprinkles it with dust, can he make that small fire blaze?"

"No indeed, Lord."

"Just so, when the mind is sluggish it is the wrong time to cultivate the enlightenment-factors of tranquillity, concentration and equanimity, because a sluggish mind is hard to arouse through these factors.

"But, monks, when the mind is sluggish, that is the right time to cultivate the enlightenment-factor of investigation-of-states, the enlightenment-factor of energy, the enlightenment-factor of rapture. [2] What is the reason? A sluggish mind is easy to arouse by these factors.

"Suppose a man wants to make a small fire blaze. If he heaps dry grass, dry cow-dung and dry sticks on it, blows on it with his mouth, and does not sprinkle it with dust, can he make that fire blaze?"

"Yes indeed, Lord."

"... a sluggish mind is easy to arouse through these factors.

"Monks, when the mind is agitated, [3] that is the wrong time to cultivate the enlightenment-factors of investigation-of-states, of energy, of rapture. Why? An agitated mind is hard to calm through these factors.

"Suppose a man wants to put a big fire out. If he heaps dry cow-dung and dry sticks on it, blow on it with his mouth, and does not sprinkle it with dust, can he put that fire out?"

"No indeed, Lord."

"... an agitated mind is not easy to calm through these factors.

"When the mind is agitated, that is the right time to cultivate the enlightenment-factors of tranquillity, concentration, equanimity. Why? Because an agitated mind is easy to calm [4] through these factors.

"Suppose a man wants to put out a big fire. If he heaps wet grass, wet cow-dung, wet sticks on it and if he exposes it to wind and rain, if he sprinkles it with dust, can he put that big fire out?"

"Yes indeed, Lord."

"Just so, monks, when the mind is agitated, that is the right time to cultivate the enlightenment-factors of tranquillity, concentration, equanimity. An agitated mind is easy to calm through these factors.

"But as for mindfulness, monks, I declare that it is always useful."

Notes

1.: Bojjhanga (= bodhi-anga , lit. "limb of enlightenment") or sambojjhanga . The seven bojjhangas are so called (SN 46.5) "because they lead to enlightenment" ( bodhi ). They are: 1. Mindfulness ( sati-sambojjangha ), 2. Investigation of (Mental and Physical) States ( dhamma-vicaya-s. ), 3. Energy ( viriya-s. ), 4. Rapture ( piiti-s. ), 5. Tranquillity ( passaddhi-s. ), 6. Concentration ( samaadhi-s. ), 7. Equanimity ( upekkhaa-s. ). The text makes it clear that of these the first, mindfulness, is the most important, since it is valuable in all circumstances, whereas the others are not always appropriate.
2.: Piiti : see SN 12.23, n. 4 .
3.: Uddhata.m : not "elated" as translated by Woodward.
4.: Woodward has here, by an oversight, "is easily raised up." Below, he has correctly "is easily calmed."