The "doctrine of necessity" is a legal principle that allows individuals or authorities to take actions that would normally be considered unlawful in order to prevent a greater harm. This doctrine is often invoked in emergency situations where immediate action is required, and there are no reasonable alternatives available. It serves to justify actions taken in the interest of public safety or welfare. In many legal systems, the doctrine of necessity can apply to various scenarios, such as public officials making decisions during a crisis or medical professionals providing care in life-threatening situations. The key aspect is that the actions taken must be proportionate to the threat faced and aimed at averting significant harm.