Glossary
Qiyas
قياسDefinition
Analogical reasoning — extending an established ruling to a new case sharing the same underlying cause ('illah).
Qiyas is one of the four primary sources of Sunni Islamic law (after Quran, Sunnah, and ijma). It lets scholars rule on novel questions like cryptocurrency by analogy to classical contracts on currency, property, or commodities.
The reasoning chain matters: a strong qiyas identifies the underlying cause of the original ruling and shows the new case shares it.