Doctrine of necessity
The doctrine of necessity is the basis on which extraordinary actions by administrative authority, which are designed to restore order or uphold fundamental constitutional principles, are considered to be lawful even if such an action contravenes established constitution, laws, norms, or conventions. The maxim on which the doctrine is based originated in the writings of the medieval jurist Henry de Bracton, and similar justifications for this kind of extra-legal action have been advanced by more recent legal authorities, including William Blackstone.