B15 · باب وجوه الاعتراض على العلل · Objections to a cause whose effect is shown: which fail, which work, and how to answer a counter-case (v2/232–249)

In short

This chapter is a rulebook for debating a cause in qiyās [Overview]. Against a cause whose effect is shown in the texts, four objections fail, and a counter-case is answered by reconciling it with the cause [B15.01]. Four objections work, and the root of them all is denial, above all asking for the effect [B15.02].

The Ḥanafī answer to al-Shāfiʿī on the Ramaḍān intention turns his own reasoning against him, so the Ramaḍān fast is valid with an intention that does not name it [B15.02].

In plain words: Which attacks on an opponent's cause get nowhere? Against a cause whose effect is shown in the texts (muʾaththir, "effective"), Sarakhsī says four objections fail. A counter-case (the feature without the ruling) fails, since a feature was added or lost there. "It is wrongly built" fails, since the effect rests on text or consensus. "The ruling exists without it" fails, since a ruling may rest on another cause. Pointing to another feature of the root fails too. Still, the answerer must reconcile a counter-case with his cause, by the feature's wording, its effect, the ruling sought, or its aim. One who cannot is bound by it.
Example: The Ḥanafīs argue: "The head-wipe is a wiping, so tripling it is not sunna, like wiping on khuffs." The opponent offers cleaning with stones as a counter-case. It is none, since it removes impurity and is not a wiping. So tripling the head-wipe stays not sunna.
Who disagrees: Some thought pointing to another feature of the root is real fiqh. Sarakhsī answers that as an objection it is fruitless: qiyās reasons from some features, not all, and a root may have two causes.
Deeper: v1 B15.01; B15.06

In plain words: Which objections work? Denial is the root: the reasoner is the claimant; the questioner need only ask for proof. He may deny the cause, the feature or the condition, or ask for the effect, the real fiqh. Claimant and denier are judged by substance, not form. Reversal (qalb) turns the opponent's own feature into a witness against him. Inversion (ʿaks) draws a contrary ruling from the reversed cause; it is weak, since a questioner may not state new rulings. A counter-cause (muʿāraḍa) is sound in the branch, stating the opposite ruling in the same place; in the root's cause it is always unsound.
Example: al-Shāfiʿī says Ramaḍān is an obligatory fast, so it needs a designated intention, like the make-up. The Ḥanafīs reverse it: an obligatory fast, so once designated it needs no further designating, like the make-up. So the Ramaḍān fast is valid with an intention that does not name it.
Who disagrees: Some call opposition in the root's cause good, since only one of "measured" and "food" can be the ribā cause. Sarakhsī answers that both can be causes; a cause falls only by showing its flaw.
Deeper: v1 B15.02; B15.03; B15.04; B15.05