Not every school accepted that istihsan was law rather than a jurist's own taste dressed up as law. Al-Shafii, writing in his foundational Risala around the turn of the ninth century, attacked the doctrine directly, arguing that a jurist who rules by istihsan has in effect made himself a lawgiver, coining the line whoever practices istihsan has legislated, man istahsana faqad sharaa. His objection was structural: if judges and jurists could set aside an established analogy whenever it struck them as producing an unwelcome result, nothing would restrain that judgment from becoming simple personal preference, and the law would lose the fixed, textually anchored character that made it law rather than opinion. He wrote a separate refutation, later collected as Ibtal al Istihsan, developing the charge in detail. Hanafi and Maliki jurists answered that istihsan was not unmoored preference but a return to a stronger textual or rational consideration when a narrower analogy conflicted with it, a defense that persuaded neither Shafii's own later school nor, more emphatically, the Zahiris, who rejected both qiyas and istihsan together as equally unauthorized departures from the plain text. The disagreement was never fully resolved within Sunni law itself, and istihsan remains one of the clearest fault lines separating how the schools understand where a jurist's own judgment is allowed to end and the text's own authority must begin.