The arguments against Qiyas have been articulated mainly by the Zahiri (literalist) school, and some amongst the Mu'tazilah, including, Ibrahim al-Nazzam. Also in principle, the Shi‟a Imamiyyah do not recognise the validity of Qiyas, as they maintain that Qiyas is pure conjecture which must be avoided. In addition, the Quran, the Sunnah and the rulings of the Imams, according to the Shi'i Ulema, provide sufficient guidance for conduct, and any reference to Qiyas is unnecessary and unwarranted.14

This is definitely the view of the Akhbari branch of the Twelve Shi‟a, whose refutation of Qiyas closely resembles that of the Zahiris. But the Usuli branch of the Shi‟a validate action upon certain varieties of Qiyas, namely Qiyas whose „Illah is explicitly stated in the text (Qiyas mansus al-`‟Illah), analogy of the superior (Qiyas al-awla) and obvious analogy (Qiyas jali). These varieties of Qiyas, in their view, are not mere speculations; they either fall within the meaning of the text or else constitute a strong probability (Al-zann al-qawi) which may be adopted as a guide for conduct. But they validate this through recourse to Ijtihad and „Aql rather than Qiyas per se.15

However, those who rejected Qiyas like the Zahiris did not actually reject the principle of Qiyas because they accepted it when it came from the mantuq (uttered meaning). Being Zahiris i.e. literalists they did not take the „Illal (reasons) that were derived from the mafhum (implied meaning) for this would be following speculation and not certainty. And as for the „Illah taken from the Mantuq they did not call this Qiyas because they considered it as simply following the literal (Zaahir) meaning of the text whilst Qiyas for them was a term used to mean a speculative (Dhanni) process in legislation which they found unacceptable. That is why they rejected the term Qiyas and some of its forms though in reality they accepted it in principle.