If they claim that one Imam’s explicit designation of his successor, [and that successor’s designation of his own successor] (1), was transmitted by mass transmission, this would be countered by their opponents’ claim of an equivalent mass transmission. For if all the other proponents of explicit designation made the same claim, there would be no difference between the two claims (2).

These and other considerations show that, even if Alī’s infallibility were established (3), their doctrine (4) was not taken from him. Their very claim that Alī was infallible is like the Christians’ claim that Christ is divine, even though what they believe was not taken from Christ.

The fourth response:

Their doctrine depends upon two premises. The first is the infallibility of whichever of the Imams they attribute the doctrine to (5). The second is the authenticity of that transmission [from the Imam] (6). Both premises are false. Christ is not God; rather, he is a noble messenger. On the supposition that he were either God or a noble messenger, his words would be true; yet what the Christians assert is not something he said (7).

In this respect, Alī’s case—may Allah be pleased with him—(8) resembled Christ’s: one group exalted him beyond his proper station, while another diminished him below his proper station and thus resembled the Jews (9).

The former say of Christ:
“He is God.”

The latter say:
“He is an unbeliever