Multiple criteria necessitate multiple understandings, and multiple understandings cause discord, and discord is not good for Muslims[1]; as Allah has said: ﴿وَاعْتَصِمُوا بِحَبْلِ اللَّهِ جَمِيعًا وَلَا تَفَرَّقُوا﴾[2]; “Hold firmly to the rope of Allah all together and do not become divided.” This is also evidence that the rope of Allah is one; because if it were multiple, holding firmly to it would not lead to unity but rather would itself be a cause of division!

Moreover, it must be noted that the truth has a single, indivisible nature; because in its reality, it is nothing but existence, which has an uncompounded essence incapable of becoming multiple, and this necessitates the unity of its knowledge and, consequently, the unity of the criterion for knowing it. In other words, the truth is the creation or the legislation of Allah, which has originated from His inherent Oneness. Therefore, there is no variation within it, nor can it be found variously; as Allah has said regarding His creation: ﴿مَا تَرَى فِي خَلْقِ الرَّحْمَنِ مِنْ تَفَاوُتٍ﴾[3]; “You do not see any discrepancy in the creation of Allah,” and regarding His legislation: ﴿وَلَوْ كَانَ مِنْ عِنْدِ غَيْرِ اللَّهِ لَوَجَدُوا فِيهِ اخْتِلَافًا كَثِيرًا﴾[4]; “If it had been from other than Allah, they would surely have found within it much variation.” Based on this, the truth, whether it is the creation or the legislation of Allah, has a single existence that does not multiply, and anything other than it is considered falsehood; as Allah has said: ﴿فَمَاذَا بَعْدَ الْحَقِّ إِلَّا الضَّلَالُ﴾[5]; “Then what is after the truth except misguidance?!”

As a result, the truth is one; because it has one origin, and what is one requires one understanding, and one understanding needs one criterion.

Deniers of the Unity of the Truth and the Criterion for Knowing It

The unity of the truth, its knowledge, and the criterion that is necessary for knowing it is one of the essential matters, and doubting it is meaningless. Nevertheless, for a long time, there have been people who have doubted and even denied it.

[Sophists]

For example, it is said that in ancient Greece, there was a group who did not believe in a single existence for the truth and considered it to be subject to human opinion.

↑[1] . This is his refutation of what they narrate from the Prophet , in which he said: «اخْتِلَافُ أُمَّتِي رَحْمَةٌ»; “The difference among my nation is a mercy.” However, this is a weak hadith despite its fame, and even if it were authentic, its meaning would be different from what they have perceived; as it has been narrated from Abd al-Mu’min al-Ansari that he said: “I said to Ja‘far ibn Muhammad al-Sadiq: ‘There are people who narrate that the Messenger of Allah said: “The difference among my nation is a mercy.”’ So, he said: ‘They spoke the truth.’ I said: ‘If their difference is a mercy, then their consensus is a punishment!’ He said: ‘It is not as you and they have perceived it. He only meant what Allah, Exalted and Majestic, said: ﴿فَلَوْلَا نَفَرَ مِنْ كُلِّ فِرْقَةٍ مِنْهُمْ طَائِفَةٌ لِيَتَفَقَّهُوا فِي الدِّينِ وَلِيُنْذِرُوا قَوْمَهُمْ إِذَا رَجَعُوا إِلَيْهِمْ لَعَلَّهُمْ يَحْذَرُونَ﴾ [At-Tawbah/ 122]; “So why did not a group from each community of them migrate to obtain understanding in the religion and to warn their people when they returned to them, that perhaps they might beware?” So, He commanded them to migrate to the Messenger of Allah and visit him frequently (from different regions) in order to learn (the religion), then return to their people to teach them. He only meant their difference in localities, not a difference in the religion of Allah. The religion is but one. The religion is but one.’” Muhammad ibn Ali ibn Babawayh (d. 381 AH) has narrated this report in Ilal al-Shara’i‘ (vol. 1, p. 85).

↑[2] . Al Imran/ 103

↑[3] . Al-Mulk/ 3

↑[4] . An-Nisa/ 82

↑[5] . Yunus/ 32