Is it farther or further?
(Arabic: "to approve," or "to sanction"), among Muslim theologians, the use of one's own judgment to determine the best solution to a religious problem that cannot be solved by citing sacred texts. This approach to religious problems found special application as Islam spread to new lands and encountered new environments. Proponents of istihsan believe Muhammad sanctioned this procedure when he said: "Whatever true Muslims prefer, is preferable in the eyes of God." Most religious authorities restrict the use of istihsan to cases that cannot be satisfactorily solved by applying such other well-established norms as, for example, analogy (qiyas) and consensus of opinion (ijma'). Certain prominent theologians, however, among them ash-Shafi'i (d. 820), forbade the use of istihsan altogether, fearful that true knowledge and correct interpretation of religious obligations would suffer from arbitrary judgments infused with error. The followers of Abu Hanifah (d. 767) held the modified view that istihsan is in fact a form of analogy because any judgment about what is best necessarily follows careful consideration of all alternative solutions