The Difference between the Rules of Usul and Fiqh

One of the highly important issues within jurisprudence and its principles is the difference between the rules (Qawa’ed) of Usul and those of Fiqh (jurisprudence) and how they are distinguished and applied for derivation of legal rulings. Our understanding of this subject is that the rules of Usul (legal theories) are instruments for derivation and deduction of legal rulings. Thus, they facilitate the inference of legal commandments where the rules of Fiqh do not possess such a characteristic as they are not used to deduce legal rulings but they are guidelines towards subsidiary laws. In other words, the rules of Usul have just an intermediary rule and the rules of Fiqh are simply applied by the duty-bound. For example, the authority of a single report (khabar wahid) and the authority of the outward meaning (zawahir) are means of attaining legal rules but the rule of itlaf (wasting something) or the principle of purity (taharat) are applied to the subsidiary rules. Thus, the rule of Fiqh is a general legal ruling whereas the rule of Fiqh is simply an instrument in deducing and inferring Islamic laws. It does seem that the different definitions of the rules of Fiqh and Usul make reference to a particular aspect of a theoretical and jurisprudential issue and there is no inconsistency between them .