Argument of Antagonism
The Argument of Antagonism (Arabic: برهان التمانع), is one of the important theological arguments for oneness of God. According to this proof, the governing of two God, say administrators, can never applied coherently in a coordinated system; since the supposition of ruling two administrators over the world results in destruction of it,so leastwise, one of these Gods must be deemed as unable; therefore, there is just one God who is the governor and administrator of the world.
This proof, which is also called the Argument of Taghalub (برهان التغالب), is among the arguments adopted from Qur'an.
The simple and common version of the argument is as follows,
Suppose one of the two creators wants to create something and the other does not, there would be three states of the case:
- The will of both creators would be obtained; but, this entails to contradiction.
- No one would be obtained; it means they are both unable and they could not be creator.
- The will of one of these creators would be obtained, and the other's one would not; so the former will be omnipotent and just it is the case that could be assumed as God and creator. but, it is in contradiction with our pre-supposition.
So the pre-supposition of having two creators is false.
Some of the s introduce following verses as the Qur'anic grounds of the argument:
- Allah has not taken any offspring, neither is there any god besides Him, for then each god would take away what he created, and some of them would surely rise up against others. 
- Allah draws an example: a man jointly owned by several contending masters, and a man belonging entirely to one man: are the two equal in comparison?1 All praise belongs to Allah! But most of them do not know. </ref>Qur'an 39:29.</ref>
Some of the Islamic theologians believe that the argument of Antagonism is the strongest and clearest argument against the idea of polytheism. Twelver theologian, al-Sayyid al-Murtada mentioned this argument in its common version. Also, al-Shaykh al-Tusi adduses it in his Tamhid al-usul.
Some Twelver theologians of 7th/13th century and afterwards have had critical approach towards the argument of Antagonism. In addition of Nasir al-Din al-Tusi who criticizes this proof in one of his book and does not mention it in others, his contemporaneous scholar, Maytham al-Bahrani and also 'Abd al-Razzaq Lahiji, did not mention this argument when they were to prove the oneness of God.
Hadith Scholars' View
Commentating some narrations, Muhammad Baqir al-Majlisi mentions the possibility that those narrations may relate to the argument of Antagonism. He gives some examples for his claim such as the hadith of Hisham b. al-Hakam from Imam Ja'far al-Sadiq (a) in which Imam refers to the Qur'an 21:22 and take "the harmonious administration and perfect creation" as the reason for oneness of God.
Mystical view of Ibn 'Arabi
Basded on the Qur'an 21:22, Ibn 'Arabi says that since the world exists and it is not fallen apart, multiplicity of gods is refused. Then, he explains the argument of Antagonism in the common theological method and proves this idea that the supposition of existence of two gods entails to contradiction.
He take this argument as the same argument that Prophet Abraham (a) argued against those who believed in godhead of stars or the moon or sun. Also criticizing those who objected this argument, Ibn 'Arabi emphasizes that since this proof is mentioned in the Qur'an this is the strongest intellectual proof for the oneness of God; and if there is any other stronger proof for the oneness of God, it would be mentioned in Qur'an.
Early Islamic Philosophers
The early Islamic says it is a convincing and rhetoric argument. Most of early Islamic philosophers believed premises of the argument have been taken from the general belief and they are incompatible with philosophical bases.
if there are multiple necessary beings, then their effects will be the same, because they are the same in the necessity of existence which is the reality of their essence. Since their effects could be the same, ascribing the effect to one of whom is giving preponderance without a preponderant which is impossible. Also, ascribing the effect to the both causes entails to the issue of single and special effect from multiple causes which is impossible too. Therefore, multiplicity of the Necessary beings is impossible.
Contemporary Islamic Philosophers
Some contemporary thinkers refuse all criticisms towards the argument of antagonism, and they reply them. Some others say some criticisms are sound. Another group of thinkers believe that these criticisms are rejected only in theological bases of Mu'tazilites and Ash'arites and They have tried to present a new sound version of the argument.
In Nihayat al-hikma, 'Allama Tabataba'i considers the argument of antagonism related to the Unity of God with regard to His lordship. He argues that multiple administrator for the world entails to destruction of the world's system. In other word, he proves having multiple gods end up to impossible.
Interpreting Qur'an 21:22 and emphasizing on the fact that the main disagreement between Unitarians and pagans is, often, the issue of sovereignty (or lordship) of God, 'Allama Tabataba'i criticizes those who consider this argument as a convincing argument; and he says the reason of their wrong imagination is that they consider Qur'an 21:22 related to the prove of oneness of the Creator, while it is to state the impossibility of multiplicity of administration and it includes a proof with some certain premises.
- Qur'an 21:22.
- Qur'an 23:91.
- The material for this article is mainly taken from برهان تمانع in Farsi WikiShia.