Different methods of formulating new laws

The four Jurists (Imāms) who are accepted by the entire Sunnī world of Islām, are thus agreed in giving an important place in legislation to Ijtihād, and the Shī‘as attached to it an even greater importance.3 In fact, the sphere of Ijtihād is a very wide one, since it seeks to fulfil all the requirements of the Muslim community which are not met with expressly in the Holy Qur’ān and the Ḥadīth. The great jurists of Islām have endeavoured to meet these demands by various methods, technically known as qiyās (analogical reasoning), istiḥsān (equity), istiṣlāh (public good), and istidlāl (inference). Before proceeding further, a brief description of these methods may be given to show how new laws are evolved by adopting them.4

Qiyās or reasoning based on analogy

The most important of these methods, and the one which has almost a universal sanction, is qiyās5 which may be described as ‘reasoning based on analogy’. A case comes up for decision, which is not expressly provided for either in the Holy Qur’ān or in the Ḥadīth. The jurist looks for a case resembling it in the Holy Qur’ān or in Ḥadīth, and, by reasoning on the basis of analogy, arrives at a decision. Thus it is an extension of the law as met with in the Holy Qur’ān and Ḥadīth, but it is not of equal authority with them, for no jurist has ever claimed infallibility for analogical deductions, or for decisions and laws which are based on qiyās; and it is a reorganized principle of Ijtihād that the jurist may err in his judgment. Hence it is that so many differences of juristic deductions exist even among the highest authorities. From its very nature the qiyās of one generation may be rejected by a following generation.

Istiḥsān or Exercise of Private Judgment and Istiṣlāh or Deduction based on Public Good

Istiḥṣān,6 in the terminology of the jurists, means the exercise of private judgment, not on the basis of analogy but on that of public good or the interest of justice. According to the Ḥanafī school, when a deduction based on analogy is not acceptable either because it is against the