If someone says:
“Alī and al-Husayn abandoned fighting [in the end] (1) only because they were unable to continue, since they had no supporters (2). Fighting would therefore have entailed the loss of life without securing the desired benefit.”
He is answered:
“This is precisely the wisdom taken into account by the Lawgiver—may Allah bless him and grant him peace—when he forbade rebellion against rulers and encouraged people to refrain from fighting during civil strife, even though those who engage in such fighting believe that their aim is to enjoin what is right and forbid what is wrong—like those who rebelled at al-Harrah and Dayr al-Jamājim against Yazīd, al-Hajjāj, and others.
“But when a wrong cannot be eliminated except through something still worse, eliminating it in that manner becomes (3) a wrong. And when what is right cannot be achieved except through a wrong whose harm outweighs the benefit of that right, achieving it in that manner is itself a wrong.
“It was on this basis that the Kharijites came to deem it lawful to take up the sword (4) against the people of the qiblah, until they fought Alī and other Muslims. The same applies to those among the Mu'tazilites, Zaydis, jurists, and others who agreed with them regarding armed rebellion against rulers [in general] (5), such as those who rebelled alongside Muhammad ibn Abd Allah ibn Hasan ibn Husayn and his brother, Ibrāhīm ibn Abd Allah [ibn Hasan ibn Husayn] (6), as well as others. The religiously committed among these groups seek to establish what they regard as religion.”