Intrinsic goodness belongs to acts such as faith, truthfulness, justice and prayer. Whether a particular obligation is fulfilled, remains, or is legally removed is then examined according to the rules governing that duty.
Instrumental goodness belongs to means related to another objective, such as reaching Friday prayer and obtaining purity for prayer. Repeating a means is not independently necessary when its objective is already secured or the relevant need has ceased.
Comparison: prayer is worship in itself, while ablution secures a condition for its validity. Ablution alone does not fulfill the prayer obligation, yet already valid purity does not need to be recreated merely because prayer time begins.
The classification clarifies whether the duty itself needs performance, the law has removed it, or only the need for a particular means has ended.