Analysis of St. John of Damascus's Apologetic Arguments
St. John of Damascus did not engage with Islam as a completely separate religion but as a Christian heresy. His apologetic approach was built on a three-step method:
St. John of Damascus did not engage with Islam as a completely separate religion but as a Christian heresy. His apologetic approach was built on a three-step method:
- State the Islamic belief as he understood it
- Defend the Christian position using logic and scripture
- Refute the Islamic position by highlighting what he saw as its internal contradictions, lack of verification, and irrationality.
He built these arguments by drawing from his deep theological formulations, especially those articulated in his masterwork, Orthodox Faith.
Islam as a Man-Made Heresy
John’s foundational argument was that Islam was not a divine revelation but a human invention derived from a corrupted understanding of Christianity.
He directly labels Islam a „coercive religion‟ and the „forerunner of the Anti-Christ‟ (Heresy of the Ishmaelites [HER] 1-2). He constructs a specific historical narrative for its origin, claiming Muhammad did not receive revelation but was instead influenced by a heretical Arian monk.
…a false prophet, called Mamed, sprung up among them; who, after conversing with an Arian monk concerning the Old and New Testament, fabricated his own heresy.
By framing Islam as an offshoot of Arianism, John immediately places it within a category familiar to any educated Christian of his time: a well-known and condemned heresy. Arianism’s central error was the denial of Christ’s full divinity, which was precisely the main point of contention with Islam. This move cleverly reframes the debate on John’s terms, suggesting Islam is not a new truth but an old error.
This argument stands in direct opposition to the Qur’an’s self-proclamation as the final, perfect revelation correcting the errors of Jews and Christians („People of the Book‟).
for you Islam as religion.‟
The Unverified Prophet
John consistently attacked the legitimacy of Muhammad’s prophethood by contrasting it with the established standards for prophets in the Judeo-Christian tradition.
He argues that Muhammad’s mission lacks two crucial proofs: prior prophecy and public witness. The Christian prophets were foretold, and their most significant revelations (like the Law given to Moses) occurred publicly. Muhammad, he claims, had neither.
„For the one who has handed down this scripture to you has no verification from any source, nor is there any prior witness to him known. Furthermore, he received this while asleep!‟
John establishes a biblical standard and then demonstrates how Muhammad fails to meet it. He uses a logical challenge that he repeats in his dialogues: if witnesses are required for mundane transactions like marriage or buying property, how much more so for receiving the very faith one lives by? The Saracen’s only recourse in the dialogue is the appeal to raw divine power: „God does as he pleases‟ (Heresy of the Ishmaelites [HER] 46), which John presents as an admission of a lack of rational defense.
The Qur’an presents Muhammad as the „Seal of the Prophets,‟ the final messenger in a long line that includes Abraham, Moses, and Jesus. His authority rests on the message itself—the Qur’an—which is considered his standing miracle.
The "Mutilation" of God
John’s most sophisticated argument leverages a core Islamic affirmation about Christ—that He is the „Word‟ and „Spirit‟ of God—to defend the Trinity.
John turns the Muslim accusation of shirk (associating a partner with God) on its head. He argues that if Christ is the Word and Spirit of God, and that Word and Spirit are not eternally co-existent with God, then there was a time when God was without His Word and Spirit—a diminished, „mutilated‟ being.
„Consequently, by avoiding the association of a partner with God, you have mutilated him. It would be far better for you to say that he had a partner, rather than mutilate him… we will, in turn, call you “κόπτας” (Mutilators) of God.‟
(Heresy of the Ishmaelites [HER] 74-77)
This polemical point is directly built upon his formal theology articulated in Orthodox Faith. There, he explains that God’s Word (the Logos) is not like human speech that dissipates but is an eternal, subsistent reality within the Godhead.
„For there never was a time when God the Word was not.‟ (Orthodox Faith 1.6, p. 174)
„If, however, the Word is outside of God, then, according to you, God is without Word and Spirit.‟
(Heresy of the Ishmaelites [HER] 72-73)
He establishes the theological principle in Orthodox Faith and then weaponizes it as a sharp, memorable dilemma in Heresy of the Ishmaelites and the Disputation.
John is directly engaging with specific Qur’anic language about Jesus. His argument forces a choice: either accept the Christian understanding or render these Qur’anic verses incoherent.
Jesus, the son of Mary, was but a messenger of Allah and His word which He directed to Mary and a spirit [proceeding] from Him. So believe in Allah and His messengers. And do not say, ’Three’…‟
The Two Natures of Christ
John addresses the common Muslim objection that a being who eats, drinks, and sleeps cannot be divine by explaining the Chalcedonian doctrine of Christ’s two natures.
He distinguishes between the actions of Christ’s human nature and the being of his divine nature, which remain united in one person (hypostasis).
„The pre-eternal Word of God… became a perfect man… this is the one who ate and drank and slept. In contrast, the Word of God did not eat, nor did he drink, nor did he sleep, nor was he crucified…‟
(Disputation between a Christian and a Saracen [DIS] 8.1-8)
This is a simplified, apologetic presentation of the complex Christology he lays out in Orthodox Faith. In both the Disputation and Orthodox Faith, he uses the exact same unique argument to prevent misunderstanding: the Incarnation does not add a „fourth person‟ to the Trinity.
This parallel shows how he translated his high theology into a practical tool for dialogue, demonstrating consistency and a clear pedagogical strategy.
The Qur’an repeatedly emphasizes Jesus’s humanity, including his need for food, as proof that he is not divine.
eat their (daily) food. See how Allah doth make his Signs clear to them; yet see in what ways they are deluded away from the truth!‟
Morality and Common Sense
John frequently employed ridicule and reductio ad absurdum to portray Islamic scripture and practices as irrational and morally inferior.
He criticizes Islamic practices like the veneration of the Ka’ba stone by contrasting it with the Christian veneration of the cross. He also recounts narratives like the „Camel of God‟ and the story of Muhammad and Zayd’s wife to paint them as foolish or morally compromised.
with a woman upon it, or that he tied a camel to it? Yet you convict us of venerating the cross of Christ, through which the power of demons and the deception of the devil have been destroyed?”
(Heresy of the Ishmaelites [HER] 88-91)
(Heresy of the Ishmaelites [HER] 107-108)
This method is less about theological debate and more about polemical persuasion. He aims to make the opposing belief seem ridiculous to his Christian audience, thereby strengthening their resolve not to convert. He juxtaposes what he presents as a carnal, earthly practice (kissing the stone) with a spiritual, powerful one (venerating the cross), creating a sharp and memorable contrast designed to prove Christian superiority.
John’s version of the Zayd story is a hostile interpretation of the events described in the Qur’an, which presents the marriage as a divine command intended to abolish a pre-Islamic taboo regarding adopted sons.
that there would not be for the believers any difficulty concerning the wives of their adopted sons when they no longer have need for them.‟
From: „John of Damascus, First Apologist to the Muslims: The Trinity and Christian Apologetics in the Early Islamic Period“ by Daniel J. Janosik