Ali—may Allah be pleased with him—also concurred with this principle, for it is reliably established that he said:

“My opinion and Umar’s concerning slave women who had borne their masters children was that they should not be sold. I have since come to believe that they should be sold.”

His judge, Ubayda al-Salmānī, said to him:

“Your opinion when you agreed with Umar is dearer to us than your opinion alone when you differed from him.”

Thus, Ali held two views on the issue. It is well known that he did not overturn what he and Umar had previously ruled concerning their emancipation and the prohibition of their sale. Rather, he held that henceforth he would rule anew that they could be sold.

There are many issues on which Ali held two or more views. Even regarding the grandfather’s inheritance alongside siblings, numerous differing positions have been reported from him.

It is also reported that whenever one of his deputies wrote to ask him about a case of this kind, Ali would instruct him according to his own independent legal reasoning and say, “Tear up the letter.” This was because he—may Allah be pleased with him—believed that he spoke on the matter through independent legal reasoning only because necessity required it, and he was compelled to exercise such reasoning in that particular case. He disliked that others should follow him without exercising independent legal reasoning themselves, so he ordered the deputy to tear up the letter.

By contrast, if he possessed an explicit text concerning the matter, he would convey it to the deputy, instruct him to transmit it, and would not order him to tear up the letter.

The scholars differ over the sale of books containing knowledge based on reasoned opinion: as to whether [its sale and the other rulings concerning it] (1) are permissible, there are two views.