Qiyas, according to jurists, is the process of deducing the ruling on a matter for which there is no divine text, from the ruling on a similar matter for which there is a divine text, due to the similarity between the two matters. It is valid in most Islamic sects, especially in hanafi. However, it is not valid in Shia, Zahiri, and many of the Ahl al-Hadith; because the rulings of Sharia are not based on comparison but only on hearing, meaning that they are known only through the text of the Legislator, as we have presented in the answer above. Yes, the proponents of qiyas quote the text of the Legislator as evidence for its validity, such as His words that has said: ﴿لَقَدْ كَانَ فِي قَصَصِهِمْ عِبْرَةٌ لِأُولِي الْأَلْبَابِ﴾[1]; “Indeed, there is a lesson in their stories for people of understanding,” and said: ﴿فَاعْتَبِرُوا يَا أُولِي الْأَبْصَارِ﴾[2]; “So learn your lesson, O people of insight”; considering that the human being’s learning a lesson from the past people means comparing himself with them and deducing his end from their end, due to his similarity to them in beliefs and deeds, and this indicates the validity of qiyas in Sharia. However, those who oppose qiyas also quote the text of the Legislator as evidence for its invalidity, such as His words about Satan: ﴿قَالَ أَنَا خَيْرٌ مِنْهُ ۖ خَلَقْتَنِي مِنْ نَارٍ وَخَلَقْتَهُ مِنْ طِينٍ﴾[3]; “He said: ‘I am better than him. You created me from fire and created him from clay,’” and His words about Pharaoh: ﴿أَمْ أَنَا خَيْرٌ مِنْ هَذَا الَّذِي هُوَ مَهِينٌ وَلَا يَكَادُ يُبِينُ﴾[4]; “Or am I not better than this nobody who can hardly express himself?”; since He has considered the comparison between fire and clay and the comparison between richness and poverty to deduce superiority to be invalid, and this indicates that qiyas is invalid with Him, but rather it is a satanic and pharaonic act. It is possible to combine these two views in two ways:

Firstly, qiyas only leads to conjecture, but conjecture is sufficient for precaution and avoiding danger in matters related to the outcome; because the intellect necessitates avoiding an assumed danger. Therefore, when one sees that a severe punishment befell a people who disbelieved in Allah or disobeyed His Messenger, he knows that if he too disbelieves in Allah or disobeys His Messenger, a severe punishment may befall him, just as it befell them, even if it is not a predetermined matter, and this is sufficient to be wary and take precautions and to avoid disbelief and disobedience. Perhaps this is the meaning behind the words of Allah Almighty, where He has said: ﴿الَّذِينَ يَظُنُّونَ أَنَّهُمْ مُلَاقُو رَبِّهِمْ وَأَنَّهُمْ إِلَيْهِ رَاجِعُونَ﴾[5]; “Those who assume they will meet their Lord, and that they will return to Him”; because when an intellectual assumes that he will meet his Lord and return to Him, he will be wary and take precautions by avoiding disbelief and disobedience; how would it be when he is certain?! However, conjecture is not sufficient for knowing the rulings of Allah; because Allah has forbidden speaking about Him without knowledge. Therefore, the permissibility of qiyas in matters related to the outcome does not mean its permissibility in matters related to the rulings of Allah, and comparing one with the other is a false comparison.

Secondly, Allah has commanded practicing qiyas in some verses and forbidden it in some others. This means that qiyas is not absolutely valid or absolutely rejected with Him, but rather it is valid in some cases and rejected in some others; because in some cases, the reason for a ruling is known from his text and is certain to exist in another matter. For example, when He says: “Wine is forbidden because it is intoxicating,” it is understood from it that every intoxicant is forbidden, even if it is not called wine. Therefore, beer is also forbidden; because it is intoxicating like wine. This is called «قياسًا منصوص العلّة», which means qiyas with explicitly mentioned reason, and the majority of scholars believe that it is valid. The objection that arises here is that the reason for the ruling may be incomplete. For example, if the reason for the prohibition of wine is that it is intoxicating and that it is what polytheists do, then the first reason is deemed sufficient to be mentioned; because it is more important, even though it is not a complete reason, and based on this, it is not permissible to decree that beer is also forbidden; because there is no knowledge that the complete reason exists in it. This objection is accepted, but it does not require the invalidity of qiyas completely and only requires its invalidity before searching for other possible reasons; because if there is another reason for a ruling, then Allah is required to declare it so that it is not considered as leading into ignorance. If there is no declaration from Him, then it is known that the stated reason is the complete reason. For example, if Allah has declared the basis of a ruling as a universal major premise, then that ruling can be applied to every matter in which that basis certainly exists until a specifier is found; because the mere possibility of the existence of a specifier does not require the annulment of the general ruling and only requires searching for the specifier, and if the specifier is not found after searching for it as much as possible, then it is permissible to act upon the general ruling. This is based on the authenticity of what is general, the abhorrence of punishment without explanation, the abhorrence of a delay in explaining at the time when it is needed, and the abhorrence of imposing what is not possible. Similarly, if the reason for a ruling is more apparent in another matter, then a fortiori the ruling applies to it. For example, from the words of Allah Almighty about parents: ﴿فَلَا تَقُلْ لَهُمَا أُفٍّ﴾[6]; “So do not say to them: ‘Fie,’” it is understood that a fortiori reviling them is forbidden, and no one can say: “Allah has only forbidden saying ‘fie’ to them and has not forbidden reviling them.” This is called «قياس الأولويّة» which means qiyas based on a stronger reason, and it is also considered valid with the majority of scholars.

However, the first view is the correct one; because what is called qiyas based on a stronger reason and qiyas whose complete reason is a divine text are not actually qiyas; considering that qiyas, as we said, is “the process of deducing the ruling on a matter for which there is no divine text,” and the ruling on the matter in these two is stated. In other words, qiyas is used in the absence of a divine text, but these two are used when there is a divine text as an inference from it; because the inclusion of the ruling on one matter in the other in these two is evident from the divine text, either verbally or intellectually, like the manifestation of the general ruling in its individuals, and the manifestation is definitely proof and is not part of qiyas in any way. However, if qiyas is the complete reason for the ruling, it is not known from the divine text or is not certain to exist in another matter. For example, if Allah has made the payment of Zakat on wheat obligatory and there is conjecture that the complete reason is its being in general use, then it is decreed that the payment of Zakat on rice is obligatory as well; because it is in general use like wheat. This is called «قياس مستنبط العلّة» which means qiyas with inferred reason, and it is undoubtedly invalid; because it is based on conjecture and guess, while conjecture and guess are not valid in Islam; as Allah Almighty has said: ﴿إِنْ يَتَّبِعُونَ إِلَّا الظَّنَّ وَإِنْ هُمْ إِلَّا يَخْرُصُونَ﴾[7]; “They follow nothing but conjecture and do nothing but guess.”

Based on this, deducing the ruling on a matter from the ruling on another matter, if it is based on knowledge about the complete reason for the ruling and its existence in the matter equally or more, is not considered qiyas, but rather it is understanding and reflecting on the Quran and the Sunnah, with which there is nothing wrong; because it is following knowledge, not conjecture, and religion will be obliterated without it. However, if it is based on conjecture about the complete reason for the ruling and its existence in the matter equally or more, it is considered qiyas, which is absolutely not permissible; because it is following conjecture, not knowledge, and religion will be obliterated with it.