1. Consideration of General Welfare (Istislâh): This is establishing injunctions on the basis of broad aspects of human welfare (maslahah mursalah in Arabic) neither expressly considered nor rejected by the sacred texts. This consideration must remain within the confines of the general consideration for human welfare evident in the Sharî`ah with its concern for attaining that which is beneficial and avoiding that which is harmful. The sacred texts and the principles of the Sharî`ah clearly indicate the necessity of taking these factors into consideration when regulating all aspects of human life, though they do not pinpoint the specific ways in which these issues might be made manifest. That is why the consideration is of “broad aspects” of human welfare, since they have not been strictly defined. If, on the other hand, the specific means of realizing an issue of welfare is enjoined by the texts themselves – like the recording and preservation of the Qur’ân or the importance of reading and writing – then it is an injunction established by the texts and is not considered as an issue falling under the principle of considering the general welfare. Likewise, if the texts indicate that the consideration of a certain aspect of general welfare is rejected – like the preservation of life that might be achieved by surrendering to the enemy, for example – then it is outside the scope of the Sharî`ah, for it has been rejected on account of a greater manifestation of human welfare that takes precedence over it – in this case, protecting the honor and might of the Islamic nation.
In general, we can say that the factors that encourage a jurist to consider the general welfare are the following:
a. Attaining that which is beneficial: This means attaining that which society needs so that human life can be maintained in the best, most dignified manner.
b. Avoiding that which is harmful: This entails avoiding those things that can cause detriment either to the individual or to society, regardless of whether this harm is of a material nature or a moral one.
c. Preventing wrongdoing: This entails preventing the means by which the commands of the Sharî`ah are neglected or its prohibitions are violated, even if only unintentionally.
d. Changing times: This refers to the changing circumstances people find themselves in. Each of these four factors requires the jurist to resort to considering the general welfare in order to produce new injunctions that can effectively carry out the general objective of the Sharî`ah to establish society in the best manner possible. A good example of the application of this principle is an act initiated by the second Caliph, `Umar b. al-Khattâb. He established the general registry for the armed forces to set their salaries and their terms of service. He then established registries for other purposes.
In the same vein are the traffic laws of today that came in response to the demands of the automobile and were set down in order to preserve life and prevent collisions and accidents.
2. Customary Practice (`Urf): The Arabic word `urf refers to that which is well known, widely accepted, and regarded as correct among those of sound mind. We find it used in the Qur’an in the following verse:
Show forgiveness, enjoin what is good (al-`urf), and turn away from the ignorant ones.
According to our definition, it should be clear that something should not be considered customary practice if it is not consistently applicable to all or most of the members of a given population. This means that the majority of the people must take it into consideration and act on it basis, like the custom today in