“So We gave Solomon understanding of the case, and to each We gave judgment and knowledge.”

Such is the case with those who exercise independent judgment, inquiry, and reasoning from evidence in fundamental and subsidiary matters. None of the early Muslims or the imams distinguished between fundamental and subsidiary matters. Indeed, dividing religion into “two categories”—fundamentals and subsidiary matters—was unknown among the Companions and their successors. None of the early Muslims, the Companions, or their successors said that a scholar who exhausts his efforts in seeking the truth incurs sin, whether in fundamental or subsidiary matters. Rather, this distinction originated with the Muʿtazilah and was introduced into the principles of jurisprudence by those who transmitted it from them.

They reported that ʿUbayd Allāh ibn al-Hasan al-ʿAnbarī said, “Everyone who exercises independent judgment is correct,” meaning that he incurs no sin. This is the position of the majority of the imams, such as Abū Hanīfah, al-Shāfiʿī, and others. Hence, they accept the testimony of adherents of deviant doctrines and pray behind them. As for those who reject their testimony—such as Mālik and Ahmad—this does not necessarily imply their sinfulness. Rather, the purpose is to denounce wrongdoing and shun those who openly display religious innovation. When such a person is shunned, people refrain from praying behind him, and his testimony is not accepted, this serves to prevent him from openly displaying religious innovation.

For this reason, Ahmad and others distinguished between someone who advocates religious innovation and openly displays it, and someone who does not. Likewise, al-Khiraqī said:

“Whoever prays behind someone who openly displays religious innovation or wrongdoing must repeat the prayer.”

A fuller discussion of this belongs elsewhere.