Imamate is located at the heart of the ideological system of Imami Shi’is. In this school, the way in which Imam is determined and appointed is other than other schools. Since they considered the station of Imamate as a continuation of the station of prophethood, Imamis were, since the beginning, of the opinion that the Commander of the Faithful, Ali (a.s.), was Imam not because of his countless virtues or since he had been elected by Muslims, but since he had been introduced and appointed by the Holy Prophet (S). In the scientific terminology of Imami thinkers, this approach was explained on the basis of the theory of “Nass” (mention). Concerning “universal Imamate” (i.e. the station of existence), they came to the conclusion that Nass (mention) is the only way to introduce the Imam. Thus, they went to reject other ways. Concerning particular Imamate (the station of affirmation), they proved Imamate of the Commander of the Faithful, Ali (a.s.), on the basis of apparent and hidden Nass as well as actual Nass (miracles). The author of the present article has studied Imamis’ theory of Nass through a descriptive-analytic approach
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