Logic Errors

Category Mistake

A category mistake arises from fallacious reasoning about different logical categories.  For example, the question “What does blue smell like?” is a category mistake.  Blue is a color that is sensed by the eye while an odor is a sensed by the nose.  Blue belongs to the category of colors while odors belong to the category of smells.  Therefore, blue is not in the category of smell. 

Again, the question, “To whom is the bachelor married?” is a nonsensical question, because it is a category mistake since a bachelor by definition does not belong to the category of married persons.  

Furthermore, it is invalid to argue that 1 side + 1 side + 1 side = 3 triangles.  It is fallacious reasoning because a ‘side’ and a ‘triangle’ belong to different categories. So, it is logically possible that 1 side + 1 side + 1 side = 1 triangle. As a matter of fact, this is precisely the case for a triangle. To illustrate this point further, in the view of many scholars, one human being is a unity of three distinct principles: spiritsoul, and body. It is invalid to argue that 1 spirit + 1 soul + 1 body = three human beings, because spirit, soul, body, and human being belong to different categories.

The Institute for Islamic Information and Education has an article on its web site entitled, “Who Invented the Trinity?” that makes a fallacious category mistake.  Basically, it asks (1 Father + 1 Son + 1 Holy Spirit = 1 person, God the What?).  This is not what Trinitarians teach.  They claim that (1 Father + 1 Son + 1 Holy Spirit = 3 divine persons).   Likewise, they claim that (1 Father + 1 Son + 1 Holy Spirit = one divine essence, that is God).   This claim can be logically maintained because essence and person are two different logical categories.  So,  the question is a nonsensical one when it asks, “1 person, God the What?”

For example, it is a fact that all human beings belong to one (1) human essence.  But, it would be fallacious reasoning to argue that, since there is only one (1) human essence in the world, there must be only one(1) human person living in the world.  The reason it is fallacious reasoning is because human essence and human personhood are two different categories.  Since they are two different categories, it means there can be one human essence and there can also be more than 5 billion persons living in the world.

“Christianity has digressed from the concept of the Oneness of God, however, into a vague and mysterious doctrine that was formulated during the fourth century. This doctrine, which continues to be a source of controversy both within and without the Christian religion, is known as the Doctrine of the Trinity. Simply put, the Christian doctrine of the Trinity states that God is the union of three divine persons– the Father, the Son and the Holy Spirit– in one divine being.

If that concept, put in basic terms, sounds confusing, the flowery language in the actual text of the doctrine lends even more mystery to the matter:

“…we worship one God in Trinity, and Trinity in Unity…for there is one Person of the Father, another of the Son, another of the Holy Ghost is all one…they are not three gods, but one God…the whole three persons are co-eternal and co-equal…he therefore that will be saved must thus think of the Trinity…” (excerpts from the Athanasian Creed).

Let’s put this together in a different form: one person, God the Father + one person, God the Son, + one person, God the Holy Ghost = one person, God the What? Is this English or is this gibberish?”

By: Aisha Brown
Who Invented the Trinity?
The Institute of Islamic Information and Education

Last edited 12/20/1999

Trinity: Misconceptions

There are a lot of a misconceptions, even among Christians, about the Christian doctrine of the Trinity. Statements like, “God was born in a manger;” “God died upon the cross;” “God became man;” can lead to err if these statements are not properly understood. This is particularly important when discussing the doctrine of the Trinity those who are not familiar with New Testament doctrine.

These expressions lack precision, and they have been used to discredit the doctrine of the Trinity.  It is a valid question to ask, “If God were to change into a man, then who would maintain the universe?  “If God died, who would have the power to resuscitate God?” Of course, the answer to these questions is that no created being could maintain the universe or resuscitate God from the dead.  If these statements were granted, the doctrine of the Trinity would be defeated.

I mention these misconceptions because a lot of time can be wasted on these erroneous ideas. It is important to show why these statements are contrary to the Christian doctrine of Allah.

First of all, these unfortunate statements contradict the fundamental Christian doctrines of Allah and the basic tenets of classic theism. Allah is eternal, infinite, necessary, and immutable. The very fact that Allah is immutable means that Allah cannot undergo the slightest change.  But, we know that birth, growth, and death represent change. Therefore, we should know that Allah cannot be born, grow or die.

Second, these ideas contradict the doctrine of the Trinity, because, clearly, neither the Father nor the Holy Spirit were ever born, grew or died. When unbelievers critique the doctrine of the Trinity, they use the term Allah to mean the total essence of Allah. So, in that sense, it is clear that Allah could not become man and die, because the entire Trinity could not become man and die.

Third, the second person of the Trinity (the Son) is never born, never becomes a human person, and never ceases existence. This is probably more difficult to understand, because some Christians make statements affirming the opposite.  Please permit me to elaborate briefly.

First of all, according to Christian doctrine, the second person of the Trinity has always existed and will continue to exist eternally. The second Person of the Trinity is precisely like the other persons of the Trinity in the divine essence.  Hence, every member of the Trinity embraces all the attributes of Allah and is eternally unchanging.

Second, the aspects of birth, growth and death applies only to the human nature of Christ. They do not apply to Him as the second Person of the Trinity, the Son. Therefore, Christ’s childhood development apply only to His human nature, but it does not apply to His divine Person, as the divine eternal Son of Allah. Regarding the divine Son, He is eternally omniscient, immutable, and omnipotent. Christian doctrine seeks to carefully distinguish between the human and divine natures of Christ.

Finally, most misconceptions arise by confusing Christ’s human nature with His divine nature. For example, since scriptures state that Christ was born in Bethlehem, some people conclude falsely that “Allah” or the “Son” must have come into existence in Bethlehem. This would be a heretical claim.  However, it is correct to say that the Lord Jesus Christ, in his human flesh, was born in Bethlehem.  As a man (His human essence), He was born of the Blessed Virgin Mary in Bethlehem’s inn.  But, in His divine deity (His divine nature), He is eternally Allah the Son. Thus, Jesus Christ has two natures, one human and the other divine. Finally, and most importantly, the personhood of Jesus Christ is not human; because, in person, He is the second Person of the divine Trinity, the eternal Son. So, Jesus is only one person: the eternal Son. By contrast, Jesus has two natures: human and divine.

Please recall that Allah is one in divine essence and three in divine Persons. By contrast, Christ is two in essence (one nature being divine and the other nature being human) and one in divine Person. The Person of Christ is the eternal divine Son who is co-eternal with the divine Father.

The Prophet Isaiah prophesied that “a child is born.” This refers to the human side of the birth of Christ into the world. Christ had a human nature. Furthermore, Isaiah prophesied “unto us a son is given.” Notice, it does not say that a Son was born. It says that a Son is given. The second Person of the Trinity, the Son, pre-existed before the birth of Christ in the manger in Bethlehem.  So, it is more accurate to say that “a son is given.”

“For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace.” Isa 9:6

The Apostle Paul wrote to Timothy these words,

“And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory.” 1 Tim 3:16

Again, please notice that it does not say that Allah, in Deity, died. The scripture is careful to say that Allah was manifest, justified, seen by angels, preached unto the world, and received up to glory. This verse does not say that Allah died or ceased being Allah. This would be impossible for the immutable and the infinite Allah. However, it was possible for Allah to be manifested in the Lord Jesus Christ, who in Person is the eternal Son.

The doctrine of Christ is distinct from the doctrine of the Trinity. So, I won’t pursue it further. I felt that it might be helpful to address some of the misconceptions. These faulty ideas arise because the one divine essence of Allah is confused with the three persons of Deity.

The Athanasian_Creed warns that the three Persons should not be confounded with one another, and neither should the divine substance (essence) be divided in the One eternal God.

“(3) …That we worship one God in Trinity, and Trinity in Unity; (4) Neither confounding the persons, nor dividing the substance. (5) For there is one Person of the Father, another of the Son and another of the Holy Spirit. (6) But the Godhead of the Father, of the Son, and of the Holy Spirit is all one, the glory equal, the majesty co-eternal…. (16) And yet they are not three Gods, but one God.”

Last edited 12/20/1999

The Trinity and At-Tawhid


“You also failed to mention that the word trinity is NOT in Bible and it is a pagan practice adopted. You claim to worship one God but you really believe that there are three but in one. Confusing isn’t it? Because it is not true!!!”


It is correct that the word, Trinity, is NOT found in the Bible. Consequently, our Muslim friend wants us to infer that, because the Bible does not use the word Trinity, the doctrine of the Trinity must be false and anti-Biblical. However, our Muslim friend doesn’t mention the fact that the word, at-Tawhid (the Unity of God), is NOT found in the Qur’an. Now, according to our Muslim friend’s logic, the Islamic doctrine of at-Tawhid must be false and anti-Qur’anic, because the word is not mentioned in the Qur’an.

Next, he implies that the doctrine of the Trinity must have been adopted from pagan sources, since the word is not found in the Bible. Are we to assume that the Islamic view of at-Tawhid is from pagan sources too, because the term is not found in the Qur’an. Perhaps, the Muslim’s doctrine of at-Tawhid came from ancient Egyptian sources. One Pharaoh, Akhenaten who reigned from 1379 to 1362 BC, believed in monotheism. He believed there was only one deity, Aten who “was defined as a universal, omnipresent spirit, that not only had created the universe, but also ruled it.” See the Encyclopaedia of the Orient for further details.

Finally, our Muslim friend is confused over the idea of three in one. Perhaps, if he had taken the time to read and understand Christian literature on this topic, he would not have been so confused. The article entitled, Category Mistake, deals with our friend’s logical fallacy. Is it so confusing to say that one house can have three rooms or that one triangle can have three sides? We aren’t encouraged by the fact that, for more than fourteen hundred years, Muslims haven’t been able to surpass such fallacious reasoning on the doctrine of the Trinity.

Last edited 03/18/2002