First the categorical answer,
then the qualified,
third, the type to be counter-questioned,
& fourth, the one to be set aside.
Any monk who knows which is which,
in line with the Dhamma,
is said to be skilled
in the four types of questions:
hard to overcome, hard to beat,
profound, hard to defeat.
He knows what's worthwhile
& what's not,
proficient in (recognizing) both,
he rejects the worthless,
grasps the worthwhile.
He's called one who has broken through
to what's worthwhile,
Aims of Buddhist Education by Bhikkhu Bodhi