 For all of Ibn Rushd’s involvement in esoteric questions of Aristotelianism, he was, at the same time, a practicing judge, deeply concerned with jurisprudential theory. Ibn Rushd’s principal work in this domain is the Distinguished Jurist’s Primer, a lengthy handbook on the causes of the jurists’ disputes and a comparison between the rationales for decision-making by different Sunni schools of jurisprudence. Its originality lies in the rational mechanisms that Ibn Rushd employs to establish general rules for understanding agreements and disagreements among jurists. He writes that “our intention in these matters is only the rules governing the law, not an enumeration of the branches, which would have no end” (Jurist’s Primer 26.241 {ii.202}). So rather than focus on counting the differences that exist between jurists and schools of jurisprudence, Ibn Rushd attempts to explain these differences by referring them to their principles, rules, and the causes that regulate them. By following the points of disagreement between the jurists and deducing the causes of this disagreement, and then bringing them back to the general principles and rules equivalent to a general maxim rooted in his soul (Jurist’s Primer 24.179, 220–1 {ii.148, 184-5}), the assiduous jurist (al-mujtahid) becomes capable of deciding about the unknown situations he will face.