Uşūl al-Fiqh, the methodology of jurisprudence is an Islamic science which is developed by Shiite scholars in two recent centuries into an unparalleled intellectual, logical system of thought.

The science of uşūl al-fiqh is a science in which such rules whose results are placed in ways of deduction of juristic precepts are discussed. For instance, performing the prayers (şalāt) is mandatory in Islam, and this Qur’ānic verse proves that obligation: “And that perform the prayers.” (6:72) However, denotation of the verse is dependent upon the imperative, like “perform” in that verse, being apparent in the obligation on the one hand and Qur’ānic apparent meanings being authoritative proofs on the other. Those two issues are dealt with in the science of uşūl al-fiqh. Now, when the jurist learns through this science that the imperative is apparent in the obligation and that the Qur’ānic apparent meanings are authoritative proofs, he can infer from the said verse that the prayers are mandatory. In the same way, the deduction of every juristic precept inferred from any juristic or intellectual proof must be dependent upon one or more issues of this science.

Uşūl al-Fiqh, the methodology of jurisprudence, which is usually – and inaccurately, if not incorrectly – translated “principles of jurisprudence,” is an Islamic science that is developed by Shiite scholars in two recent centuries into an unparalleled intellectual, logical system of thought and a comprehensive branch of knowledge which not only serves as the logic of jurisprudence but as an independent science dealing with some hermeneutical problems.