Abd ul-Nabi ibn Saad al-Jazaairi (died circa 1610 AD, 1021 AH) was a Shiite biographer, cleric, and jurist. Hawi al-Aqwal fi maarifat al-rijal (The authority on discriminating scholarly men) is his four-volume anthology of biographies of Shiite scholars and other figures, who communicated the hadith, sayings attributed to the Prophet Muhammad that were transmitted by word of mouth. In order to verify the credibility of any hadith, the trustworthiness of each link (person) in the chain of narration had to be checked. Consequently, this work divides the narrators discussed into four categories: “trusted,” “studious,” “fair,” and “weak.” The volume is the first of its kind by a Shiite biographer to use such a method; earlier biographical anthologies were largely either unclassified or divided into two categories only. The categories also comprise the chapters of the work, which are organized alphabetically. The entry lengths vary, with some as short as a single sentence. Some Shiite scholars accused al-Jazaairi of having stringent views and of being quick to criticize, comparing him to Ibn al-Ghadhaairi (died circa 1050 AD), an earlier Shiite biographer, who was seen as too critical of names regarded as trusted. Al-Jazaairi, for instance, classified as “weak” Di’abil al-Khuza’ai, who is considered by many to be the unofficial poet of Aal al-Bayt, the Prophet Muhammad’s extended family. Among the other names al-Jazaairi was critical of were Saleem ibn Qais and Jabir al-Jaafi.