The Taqrib al-Wusul ila 'Ilm al-Usul of Ibn Juzayy al-Kalbi al-Gharnati (d. 741 AH/1340 CE) is a concise manual of Islamic legal theory (usul al-fiqh) composed with an explicit commitment to brevity, clarity, and sound organisation. The work comprises a preface and five chapters, each divided into ten sections, for a total of fifty sections. These treat, in sequence: rational knowledge, linguistic knowledge, legal rulings, the evidences on which those rulings rest, and the topics of independent legal reasoning (ijtihad), uncritical adherence to authority (taqlid), legal responsa (fatwa), and the reconciliation and preferential weighting of conflicting proofs. Ibn Juzayy explains that legal rulings are placed before their evidences because they are the ultimate object of the discipline, while the rational and linguistic preliminaries come first because no subsequent discussion is intelligible without them.
Ibn Juzayy drew primarily on al-Qarafi's Sharh Tanqih al-Fusul, from which he borrowed extensively and at times verbatim. He also made significant use of al-Ghazali's Mustasfa - particularly for the section on rational knowledge, where he follows the approach of the mutakallimun and logicians - and of al-Juwayni's Burhan, especially in his treatment of transmitted reports and analogical reasoning. Among works he is thought to have consulted are those of al-Baji, al-Baqillani, Ibn Hazm, and Fakhr al-Din al-Razi.
Several features distinguish the work. Ibn Juzayy consistently presents the Maliki position before noting Shafi'i and Hanafi views, then adjudicates between them on the basis of rational and textual evidence. He avoids repetition through frequent cross-references and formulates many definitions independently rather than reproducing those of earlier authorities. Extended polemical engagement is deliberately eschewed in keeping with his goal of simplification. Most distinctively, he closes the work with a chapter on the causes of disagreement among the mujtahids - a subject he considered essential for grounding confidence in the results of ijtihad, but one that earlier usulis had generally left to works of comparative jurisprudence.
