The recognition of Ignorance and its sociological attachments regarding its close proximity to Early Islamic Community is very important. Moreover the essence and the features of Ignorance indicate not only be considered to the pre-Islamic period but also on the contrary to Islam and any fundamental transition, one of the initial steps studying the ratio of a society to the Ignorance is, the perception of its meanings, concepts and subjects. Among the existing in this arena, beside the Holy Qur’an and The Hadiths of Prophet (PBUH), the sermons of Ali (PBUH) is of considerable importance. Applying descriptive approach by using the grounded theory method, through the constancy between the inductive reasoning (creating concepts, subjects and the relations in between) and deductive reasoning (examining the concepts, subjects and the relations in between). This research intends to find the dominant criteria in evaluating the ratio of society to Ignorance in Nahdj al-Balagha and renders the term “irrational-faith” as the major concept in this arena.