Shi'ism in Syria and Jabal Amil

Shakib Arslan discusses with Ahmad Rida and with the scholars of Tabriz the question of the oldest Shi'ism: was it in Syria or among the non-Arabs? This is a presentation of his own argument, and not a ruling on a historical question that is disputed. ¹

Arslan relates a report that Abu Dhar al-Ghifari was loyal to Ali and that he rebuked Mu'awiya for amassing wealth. He holds that this is enough to prove an early Shi'ism in Syria, but it is not enough by itself, and in his view it cannot be made the basis for Jabal Amil. ¹

He mentions that the Shi'a of Jabal Amil were bound by dissimulation (taqiyya) in later ages, and that many historians did not attribute their scholars to Shi'ism except under compulsion. He describes the Islamic conference of Jerusalem, saying that its members prayed behind a Shi'i mujtahid. ¹

A further source is needed: there is only one source, and the claim of dissimulation and the conference need a second source.