(salam) (bismillah) To prove this fact that there is hell of difference between Qiyas and Aql. I welcome my Usooli as well as Akhhbari brothers to come forward and prove their view point. Qiyas is totally haram in both schools of thoughts while Aql is source of law for Usoolis while Akhbaris consider it interference in the Shariah. The purpose of this thread is two fold. 1. What is difference between Qiyas and Aql? Are they the same? 2. If they are different then Is Aql source of law as Usoolis claim or it amounts to interference in Shariah? DEFINITION OF "QIYAS" (ANALOGY): In its literal meaning, the word "Qiyas" means measuring or estimating one thing in terms of another. It also applies to making two things equal, that is, comparing. This comparison may be physical or rational. In the technical sense, as defined by the jurists, it applies to "the assignment of the "hukm" of an existing case found in the texts of the Quran, the Sunnah, or ijma to a new case whose hukm is not found in these sources on the basis of a common underlying attibute called "illah" of the hukm ELEMENTS OF QIYAS: The definition of Qiyas shows that it has five ingredients or elements. 1. "Maqis alayh" (asl): This is the root case or even the base or the case upon which the analogy has been constructed. 2. "Hukm al-asl" The "Hukm" of the "Maqis alayh" is called "Hukm al-asl" 3. "illah" It means the underlying cause which is determined by the jurist that has led to the "hukm" 4. "Maqis" it means the case for which analogy (Qiyas) is constructed. 5. "Hukm al-far" The "hukm" that has been established for the new case is called "Hukm al-far"