Comparison, in the term of religious scholars, means derivation of the law of a matter from a similar matter because of the similarity between the two matters, which is considered valid by most Islamic sects especially the Hanafi, but according to the Shiite, the Zaheria and many of the Ahl al-Hadith is not valid; because religious laws do not have comparable nature, rather are totally auricular; meaning they are determined only by the lawmaker’s text. Although the people of Comparison cite the lawmaker’s text in order to prove its validity; like the words of God that has said: ﴿لَقَدْ كَانَ فِي قَصَصِهِمْ عِبْرَةٌ لِأُولِي الْأَلْبَابِ﴾[1]; “Indeed, there is certainly a lesson in their stories for those who possess intellect” and has said: ﴿فَاعْتَبِرُوا يَا أُولِي الْأَبْصَارِ﴾[2]; “So take lesson, O you who have insight”; regarding that taking lesson from the predecessors means comparing ourselves with them and deriving our destiny from their destiny because of the similarity of our acts, and this implies the validity of Comparison, but the opponents of Comparison, cite the lawmaker’s text in order to reject its validity; Like the words of God that has said about Satan: ﴿قَالَ أَنَا خَيْرٌ مِنْهُ ۖ خَلَقْتَنِي مِنْ نَارٍ وَخَلَقْتَهُ مِنْ طِينٍ﴾[3]; “He said I am superior to him, You created me from fire and You created him from clay” and as Pharaoh conveyed, He has said: ﴿أَمْ أَنَا خَيْرٌ مِنْ هَذَا الَّذِي هُوَ مَهِينٌ وَلَا يَكَادُ يُبِينُ﴾[4]; “Or am I better than this man who is nothing and he is not as near to speak clearly”; regarding that He has considered derivation of self-superiority by comparing the fire and clay and greater wealth with lower wealth as a satanic and Pharaoh-like act, and this implies the invalidity of Comparison.

It is hereby understood that in some verses, God obliges the Comparison and in some other verses, He forbids it, and it means that Comparison for Him, is neither absolutely valid nor absolutely rejected, rather it sometimes is valid and sometimes rejected; because sometimes the reason of the law is recognized from His text and it is definite in another matter; Like in a situation that He supposedly has said: “Wine is forbidden; because it is intoxicating” and it turns out that every intoxicating thing is forbidden, although it is not called wine, and accordingly, beer is also forbidden; because it is intoxicating like wine, and this is called “the Comparison in which its reason is investigated[5]” which is often considered valid, but some believe it is out of so called Comparison. Because including beer in the law of wine, is based on the lawmaker’s text and is nothing except conformity to a general on one of its instances and therefore, the above answer about invalidity of Comparison is not with regards to this type; just as sometimes the reason of law is more clear in another matter and therefore, the law is applicable per the former reasoning; like where He has forbidden to say Fie to the parents and has said: ﴿فَلَا تَقُلْ لَهُمَا أُفٍّ﴾[6]; “Do not say to them, ‘Fie” and it is hereby understood that accursing them, per same former reasoning, is forbidden and therefore, the above answer about invalidity of Comparison is not looking to this type of Comparison which is called “precedence Comparison[7]” either, but sometimes the reason of the law is given from lawmaker’s text or it is not definite in another matter, but there is an utmost conjecture to it; like where He has obliged Zakat for wheat and it is supposed that the reason is its commonality among most people and therefore, obligation of Zakat in rice is also acknowledged; because rice has become very common among people like wheat, and this is called the “the Comparison in which its reason is derived[8]”, which is undoubtedly rejected; because it is based on conjecture and estimation, whereas conjecture and estimation are not valid in Islam; as He has said: ﴿إِنْ يَتَّبِعُونَ إِلَّا الظَّنَّ وَإِنْ هُمْ إِلَّا يَخْرُصُونَ﴾[9]; “They do not follow anything but conjecture and do nothing but estimation”.

Therefore, deriving the law of a matter from another matter’s law, whenever it is based on knowledge of the standard or the reason of the law of the other matter and the knowledge of its existence or its dominance in a matter, is not considered to be an invalid Comparison, but it is Ijtihad in religion and it is investigating Quran and Sunnah, which there is no problem in it; because it is following the knowledge not conjecture, and Quran and Sunnah will be destroyed without that, but whenever it is based on conjecture to the standard or the reason of law of another matter or conjecture to its existence or its dominance in a matter, it is considered to be an invalid Comparison and is not permissible; because it is following conjecture not knowledge, and Quran and Sunnah will be destroyed with that; as God has said: ﴿وَلَا تَقْفُ مَا لَيْسَ لَكَ بِهِ عِلْمٌ﴾[10]; “Do not follow what you have no knowledge of” and has said: ﴿نَبِّئُونِي بِعِلْمٍ إِنْ كُنْتُمْ صَادِقِينَ﴾[11]; “Inform Me with knowledge, should you be truthful”.