Noting that Qiyas does not yield certainty and all that may yield is Zann it is now time to examine if this kind of Zann is Hujjah or not. If it could, in fact, be considered as Hujjah then it will fall under the category of the kinds of Zann that are exception to the verse of the holy Quran that forbid following Zann. It then will be like the case of the Hadith that is not reported unanimously.

 As far as the Shi’a school is concerned they do not entertain Qiyas as valid Hujjah because of the clear statements of the Imams (peace be up on them) against Qiyas. Such statements of the members of Ahlul Bayt (family of the holy Prophet peace be upon him) are up to the level of certainty. Such statements are up to the unanimously reported level and they all prohibit following Qiyas

 As a Shi’a Faqih one only has to examine the evidence that are advanced to prove Qiyas as Hujjah to see if such evidence could measure up and if they did not then it is back to subjecting Qiyas to the verses of the holy Quran that prohibit following Qiyas.

 The following are some presentations of evidence by supporters of Qiyas to validate it from the Holy Quran, the Sunnah, Consensus and Reason: