anyone else, necessarily, since neither the Shi'a nor others dispute that he was the one who (1) assumed authority after him and became his successor: leading the Muslims in prayer, enforcing the prescribed penalties among them, distributing the public revenues among them (2), leading them in battle against the enemy (3), appointing officials and commanders over them, and performing the other duties carried out by those vested with authority.

By universal agreement (4), Abū Bakr alone undertook these duties after the Messenger’s death. Thus, he was (5) unquestionably the successor to the Messenger—peace and blessings be upon him—in these matters.

The adherents of the Sunnah, however, say:

“He succeeded him (6) and was the one most entitled (7) to succeed him.”

The Shi'a say:

“Ali was the one most entitled (8), although Abū Bakr’s caliphate was valid.”

And they say: (9)

“It was not lawful for him to become caliph (10).”

Nevertheless, they do not dispute [the fact] (11) that he actually became caliph and is entitled to this designation, since (12), in any event, a successor is someone who succeeds another.

As for the claim that a successor is someone whom another person appoints as his successor, as held by some adherents of the Sunnah