—and they are many.

When the competing considerations are evenly matched, the maxim applies: darʾ al-mafāsid awlā min jalb al-maṣāliḥ (warding off harms takes precedence over procuring benefits).

Included here as well is the dictum: lā tatimmu al-aḥkām illā bi-wujūdi shurūṭihā wa-intifāʾ mawāniʿihā (a ruling is not complete unless its conditions are fulfilled and its impediments absent).

This, too, is a major principle upon which a vast number of legal rulings and other matters rest.

Accordingly, whenever a required condition for an act of worship, a transaction, or the establishment of rights is missing, the act is invalid.