Is an agent authorized to act alone when the principal appoints two agents for a transaction?

Primary text

If a principal appoints two agents for a transaction and grants each the authority to act independently, this is permissible because the principal has explicitly authorized it. If independent action is not specified, neither agent may act alone, as authorization was not granted for solitary action; the agent is only permitted what the principal authorized. This view is held by Al-Shafi'i and the People of Opinion (Ahl al-Ra'y).