“Bhikkhus, suppose a man were to throw a yoke with a single hole into the great ocean. And there was a blind turtle. This turtle would come to the surface once every hundred years.
What do you think, bhikkhus, would that blind turtle, coming to the surface once every hundred years, ever manage to insert its neck into that yoke with a single hole?”
“It would be very unlikely, venerable sir, that it would ever do so, only after a very long time, if at all.”
“Sooner, I say, would that blind turtle, coming to the surface once every hundred years, manage to insert its neck into that yoke with a single hole than an |undiscerning person::a person without a sense of shame or moral dread, an immature person [bāla]| who has fallen into |a lower realm::a state of suffering, underworld [vinipāta]| would regain human existence.
For what reason? Because, bhikkhus, there is no practice of the Dhamma, no wholesome conduct, no doing of wholesome actions, no performance of meritorious deeds in those lower realms. There, bhikkhus, beings devour one another, and the weaker are prey to the stronger. For what reason? Because, bhikkhus, they have not seen the Four Noble Truths. What four? The noble truth of |suffering::discomfort, unpleasantness, discontentment, dissatisfaction, stress, pain, disease, i.e. mild or intense suffering [dukkha]|, the noble truth of the |arising of suffering::source of stress, appearance of discomfort [dukkhasamudaya]|, the noble truth of the |ending of suffering::ending of discontentment, cessation of distress [dukkhanirodha]|, and the noble truth of the |way of practice leading to the ending of suffering::i.e. the noble eightfold path [dukkhanirodhagāmī]|.
Therefore, bhikkhus, effort should be made to |fully understand::understand in principle, then discern in each moment and then experientially penetrate|: ‘This is suffering’;
effort should be made to fully understand: ‘This is the arising of suffering’;
effort should be made to fully understand: ‘This is the ending of suffering’;
effort should be made to fully understand: ‘This is the way of practice leading to the ending of suffering.’”