How can we judge a narrator to be just and trustworthy, and ascertain the veracity of the narrations attributed to him in biographical literature, thereby escaping the cycle of doubt concerning the authenticity of those narrations?

The concept of an infinite regress in ascertaining the justice and disparagement of Hadith narrators would be unconvincing if approached theoretically. However, the reality of the science of al-Jarh wa al-Ta'dil (disparagement and authentication) contradicts this:

1. Antiquity and Tawatur of the Science: The science of al-Jarh wa al-Ta'dil did not begin recently; rather, it existed from the very start of narration during the era of the Companions, specifically after the Fitnah. At that time, inquiring about the chain of narration (isnad) and its narrators became essential to distinguish the Ahadith of the Ahl al-Sunnah from those of the people of innovation (ahl al-bid'ah). These narrations were documented and preserved early on.

2. Renowned Scholars of the Science: The science relies on scholars renowned in every era, whose justice and trustworthiness have reached the level of tawatur, such as Imam Malik and Ahmad. There is no need to investigate their justice or the authenticity of the chain leading to them, as their statements have been preserved in their own works or those of their students, like Ibn Ma'in and Al-Bukhari. Allah raised men who clarified the conditions of narrators, and their statements were accepted due to their intimate knowledge of them.

3. Inference and Verification: Scholars and researchers today can verify the rulings of al-Jarh wa al-Ta'dil by examining their evidence. Many of these rulings are based on scrutinizing a narrator's narrations and comparing them with others to distinguish the sound from the infirm. Al-Mu'allimi explains that the basis for authenticating a narrator is the uprightness of his narrations after scrutiny, which indicates his truthfulness and precision.

All the imams of al-Jarh wa al-Ta'dil are well-known, and their academic and religious stature is famous. There is no room for doubt concerning this science except due to a lack of knowledge and baseless conjectures.