Shakyamuni then said, “Sona, just now were you not thinking these thoughts?” And Shakyamuni enumerated the distractions that had been running through Sona’s mind. Sona admitted that all this was true.

Shakyamuni then asked Sona if he had played the lute when he lived at home. Sona said he had played it, and Shakyamuni asked, “If the strings are stretched too taut, will the lute produce a pleasing sound?”

“If the strings of the lute are too slack, will the instrument produce a pleasing sound?”

“No.”

“But if the strings are neither too taut nor too slack, but just right, the lute will produce a pleasant sound?”

“Yes, it will.”

“Well, Sona, in Buddhist discipline, if one is too eager, the mind will be shallow and unsettled. If one is too lax, the mind will become lazy. The proper way is to be neither too eager nor too lax but to make spiritual efforts and progress at a suitable pace.”

When he had heard this highly appropriate metaphor of the lute, Sona acquired the ability to go on with disciplines at a suitable pace and thus to abandon illusions and hindrances and finally to attain the ultimate enlightenment of the arhat.

No matter how eager and assiduous a person is in religious training, achieving enlightenment depends on primary and secondary causes from previous existences. For people with the right causes, the opportunity for enlightenment will come readily; for people without them, the opportunity will probably not develop. Although it is true that the buddha-nature is inherent in all sentient beings, the speed with which enlightenment is reached depends on the causes from previous existences and the causes in the present life. (Page 166-117)