Great many of the research scholars have not made any mention of the evidence from reason in support of the validity of Qiyas as Hujjah. Shaykh Al-tusi in Al- ‘uddah vol. 2 p 84 has said, "Those who belief in Qiyas have disagreed among themselves. Some of them present evidence from reason but they are very few."

 In the following although very weak are some of their best supporting arguments.

 (a) It is known that cases are so many and unlimited and texts of Shari’a are few and limited. It is not possible for the limited to cover what is unlimited. Therefore, in order to cover all cases there must be some way other than the limited texts of Shari’a and nothing else besides Qiyas is there to compensate for the limitations of the Texts.

 The answer to this argument is the existence of the texts of Shari’s which are of universal nature. The legislator does not have to establish a law for every single case. The universal laws solve this problem.