The first: When this is the only possible way, the act no longer counts as a sin, for whatever is indispensable to fulfilling an obligation or performing a recommended act is itself obligatory or recommended. If its harm is less than that benefit, it is not prohibited. Examples include eating carrion out of dire necessity and other prohibited acts that become permissible because of need, such as wearing silk in cold weather and similar cases.

This is a matter of great importance. Many people sense the wrongness of an act but overlook the countervailing need, addressing which earns a reward for good that outweighs that harm. Thus, the prohibited act becomes included among acts beloved to Allah, or becomes permissible when need alone is what weighs against its prohibition. Conversely, some permissible acts—indeed, even acts commanded as obligatory or recommended—may involve an outweighing harm that renders them forbidden or less preferable. Examples include fasting for a sick person and purification with water for someone whose life would thereby be endangered. As the Prophet, may Allah bless him and grant him peace, said:

“They killed him—may Allah kill them! Why did they not ask when they did not know? The cure for ignorance is to ask.”

This principle underlies the permissibility of sometimes departing from certain practices of the caliphs, just as necessity permits leaving some obligations of the Sharia unfulfilled and committing some of its prohibitions. This applies when one is unable to follow certain practices of theirs, or when necessity requires doing something they prohibited: namely, when the duties that governance is intended to fulfil cannot be discharged except through something whose harm is lesser.