In Islamic jurisprudence, Qiyas is the process of analogical reasoning from a known injunction (nass ) to a new injunction. It is one of the four undisputed sources of Islamic law, the others being Qur'anic interpretation, the Sunnah, and ijma (Consensus).

Example of qiyas

For example, qiyas is applied to the injunction against wine drinking to create an injunction against cocaine use.

1. Identification of a clear, known thing or action that might have bear a resemblance to the modern situation, such as the wine drinking.
2. Identification of the ruling on the known thing. Wine drinking is haraam, prohibited.
3. Identification of the reason behind the known ruling ('illah ). For example, wine drinking is haram because it intoxicates. Intoxication is bad because it removes muslims from mindfulness of God. This reason behind the reason is termed hikmah .
4. The reason behind the known ruling is applied to the unknown thing. For instance cocaine use intoxicates the user, removing the user from mindfulness of God. It is therefore prohibited.

The sometimes harsh results of qiyas can sometimes be mitigated by disputed practice of Istihsan (Equity).

see also: Zahirites and Siyasa

References

• Mohammad Hashim Kamali, Principles of Islamic Jurisprudence (2003)