Researchers in religious disciplines know that every subsidiary issue in jurisprudence involves a controversy among scholars and that difference in opinions is nothing strange in Islamic jurisprudence, but is rather an inescapable corollary.
They also know that Shariah has as its basis and foundation a group of conclusive constants unanimously agreed upon by scholars, past and present, and that beyond such constants, detailed juristic issues involve some sort of difference in opinion among scholars, whether about their supportive evidence or the denotations of statements, in a way that leads to multiplicity of opinions.
So, giving preponderance to the different opinions on juristic issues is among the frequent undertakings of those working in the field of Islamic jurisprudence.
Just like the process of comparing and choosing among given options reflects man’s priorities and preferences, the same is true when it comes to weighing different juristic opinions. Yet, one of Almighty Allah’s favors on the Muslims is that the ranks of deeds and situations are not left to be determined by personal whims and desires. Rather, they are ordered according to a well-structured system indicated in the texts of the Quran and the Sunnah and is technically known as Fiqh Al-Awlawiyyat (Jurisprudence of Priorities). This system should be a criterion and a guiding light for the jurist when choosing among the different opinions related to a certain issue.
Investigating the criteria of weighing and accrediting different scholars’ opinions should focus first on studying the methodological and Usuli reasons of juristic differences. Determining the underlying Usuli reason of difference in a certain juristic case helps in deciding the appropriate weighing methods and standards that should be applied.
Here, I recollect the words of Abu Al-Walid ibn Rushd (may Allah shower him with mercy) on the importance of “understanding the Usuli reasons that necessitated difference in opinion among jurists” to practice a sound Ijtihad or juristic reasoning. In his book, Bidayat Al-Mujtahid Wa Nihayat Al-Muqtasid [The Distinguished Jurist’s Primer], Ibn Rush said,
The purpose is the recording of the well-known issues over which dispute arose between the jurists of the regions together with the issues expressly stated by theshar`…, agreed upon or disputed…
Truly, the knowledge of these two categories of issues provides the mujtahid with general principles for those issues over which the texts are silent and in cases where disagreement among the jurists of the regions is not well known, irrespective of an opinion from any of the jurists having been related in it. It is likely that one who works through these issues and understands the principles of the causes that generated the disagreement of the jurists in them, will be able to derive what is required in each particular case,
Methodological reasons underlining juristic differences are multiple and diverse, yet I deem that they stem from the following three cases, which I think methodologically cover the areas of opinion difference in Islamic Fiqh.
First, differences due to emergent issues
In this case, an unprecedented issue emerges; it has never been handled by Muslims before nor has it been addressed by a religious text. That is why such issues are called by many scholars as non-tackled occurrences, that is, as far as scholars know, there are no detailed religious texts directly tackling the issue. However, that does not mean legal texts have nothing to do with emergent issues; rather it means that jurists need to refer to the universals, general rule and priorities inferred from texts.
Second, differences related to texts’ denotations
In this case, scholars agree to the authenticity of the legal text(s) related to respective issues, though they differ in determining the denotations of such texts in terms of rulings inferred from them.
Though such difference is due to the diverse rational approaches applied by Mujtahids (jurists practicing ijtihad), Fiqh of Priorities has to do with the criteria used to weigh scholars’ views, whether these views belong to the same school a jurist is affiliated with or to other schools.
Third, differences because of conflicting evidence
In this case, there will be more than a legal text on the issue, and juristic opinions differ due to what is called ta`arud or conflict among texts. Approaches to handle this issue are various and are discussed under the title of Hall at-ta`ard (conflict resolution).
Once again, Fiqh of priorities plays a role in reconciling textual conflict.
Shariah Objectives as bases of Fiqh of Priorities
As regards the Fiqh of Priorities mentioned in the above three cases, it has three basic collective Shar`i objectives, which I believe have a direct impact on the process of weighing different opinions and giving preponderance to certain opinions among them, namely, interest, leniency and ta`abbud (devotional obedience).
First objective: Interest
There is no difference in opinion regarding the importance of bringing about benefit and warding off harm in juristic Ijtihad (inference). Yet, the definition of interest itself and that of its opposite, i.e. harms, requires a well-founded methodology to leave no room for twisting the legal texts nor getting influenced by personal whims when inferring a juristic ruling in name of bringing about interest and warding off harm.
The question here is: how can we identify an interest?
Second objective: Leniency
Leniency [making things easy] is a fundamental concept in the process of weighing and giving preponderance to the different statements (opinions).
The urgent questions related to this concept are the following: What is the evidence for prioritizing leniency in Almighty Allah’s Shariah?
And what are the regulations controlling adoption of this concept?
Third objective: Ta`abbud
This is another important concept when weighing various opinions against each other, as scholars’ statements on numerous issues, especially in the field of women jurisprudence, are based on viewing them as Ta`abbud-related, meaning that they are intended per se and that their ruling does not vary according to the change in circumstances. So, what are theseTa`abbud-related issues and how can we differentiate between them and other issues?
 The Distinguished Jurist’s Primer,Ithaca Press, vol. 2, p. 467