How many parts is a human being composed of?
This is a question that has puzzled philosophers, theologians, and anthropologists for as long as anyone can remember. Because of the many references in Scripture to a part of a person that lives on after their body dies, viz. Jesus telling the thief on the cross that he would be with Him in paradise that day (Luke 23:43), and descriptions of the martyred saints’ activities in heaven (Rev. 6:9-11), to name a few, Christians agree that there is more to a person than just their physical body. Each person has a material side (body) and an immaterial side (soul/spirit) that will live on after their body dies. That is where the agreement ends however.
Among Christians there are two main positions on this subject:
Trichotomy is the belief that a person is composed of three parts: a body, a soul, and a spirit. The soul and spirit are said by the trichotomist to be completely different things. The soul is composed of the intellect, emotions, and will of a person. The spirit is the part of a person that communicates directly with God. The spirit is as different from the soul as the soul is from the body, making the man a three part being.
Dichotomy is the belief that a person is composed of only two parts: a body and a soul/spirit. According to the dichotomist the words “soul” and “spirit” are synonyms and refer to the same thing: the immaterial part of a person.
In this article I will endeavor to (1) explain the origin and history of the two views, (2) examine what Scripture says on the subject, and (3) look at some of the specific arguments that are used.
Before I get into the history of the two views, I would like to make it very clear that I am by no means implying that a belief is automatically false just because of where it comes from. An idea can have a tenebrous history and still be perfectly true. However, by examining the history of a belief we can better understand how it was formed and why people believe it.
Though the origin of trichotomy is hotly debated, it is most probable that it traces its roots back to ancient Greek philosophy. As Kim Riddlbarger notes, “When viewed from the perspective of Christian reflection across the ages, there is no doubt that trichotomy has a very dubious pedigree. With its roots in Plato’s distinction between body and soul, and Aristotle’s further division of soul into ‘animal’ and ‘rational’ elements, the trichotomist notion of human nature as tripartite is unmistakably Greek and pagan, rather than Biblical.” While the seeds of trichotomy were planted by the Greek philosophers, the Neo-Platonists and Gnostics had far more of an influence on the formation of what we now know as trichotomy. According to the Gnostics, the material world was evil, whereas the spiritual world was good. Since God was spirit, he was good, and could not create matter, which was evil. The Gnostics held that there had to be a series of emanations or aeons between God and the material creation. Eventually one of these emanations created matter, making the emanation responsible for bringing matter and evil into the world, not God. In Gnosticism there always has to be an intermediate substance or being between God and the material world. But what does this have to do with trichotomy? Louis Berkhof explains in his Systematic Theology:
“The tripartite conception of man originated in Greek philosophy, which conceived of the relation of the body and the spirit of man to each other after the analogy of the mutual relation between the material universe and God. It was thought that, just as the latter could enter into communion with each other only by means of a third substance or an intermediate being, so the former could enter into mutual vital relationships only by means of a third or intermediate element, namely, the soul.”
Since the body was evil and the spirit was good, there had to be some sort of a third substance or mediator between the two so that the spirit would not be tainted by the body’s evil. Trichotomy was born. Considering that the origins of trichotomy are found in Greek philosophy and Gnosticism, it should be no surprise that the main venue by which trichotomy found its way into the early church was the school of Alexandria, the center of Gnostic and Neo-platonic influence in the church. Clement of Alexandria and Origen were some of the more prominent trichotomists there. The influence of trichotomy was felt elsewhere besides Alexandria however, and many of the Church Fathers such as Justin Martyr, Tatian, and Basil of Caesarea could be considered trichotomists.
Trichotomy fell out of favor however, when Apollinaris used it to argue against the complete humanity of Christ, and when the Pelagians used it to argue against original sin. In the course of battling against these heresies, the church as a whole generally accepted the view of dichotomy. Both Athanasius and Augustine held to a dichotomist view, and because of the latter’s great influence on western Christian thought, dichotomy remained the predominate view throughout the rest of the Middle Ages. The Reformation did not really change things, and although a few lesser known Reformers and Puritans advocated trichotomy, Reformed thought has generally been dichotomous. Calvin said, “Moreover, there can be no question that man consists of a body and a soul; meaning by soul, an immortal though created essence, which is his nobler part.” There is no room for trichotomy within Reformed Confessions either. The Belgic Confession says this:
“For all the dead shall be raised out of the earth, and their souls joined and united with their proper bodies, in which they formerly lived.” (Chapter 37) 
No distinction between soul and spirit here. The Westminster Confession also assumes dichotomy:
“The bodies of men, after death, return to dust, and see corruption: but their souls, which neither die nor sleep, having an immortal subsistence, immediately return to God who gave them” (Chapter 32.1) 
The Savoy declaration repeats this part of the Westminster Confession word for word, as does the London Baptist Confession of 1689.
Dichotomy remains the dominant view to this day and is held by the majority of evangelicals. Although trichotomy still has a sizable following among the masses, there are few evangelical scholars who defend it today.
So if trichotomy appears to come from Greek philosophy and Gnosticism, where did dichotomy come from?
(2) WHAT THE SCRIPTURES SAY:
Although understanding the history behind the two views is helpful, and hearing what the confessions say is important, ultimately we must look to the Scripture to determine what is true and what is false. So how are the words “soul” (Heb. nephesh and Gk. psyche) and “spirit” (Heb. ruach and Gk. pneuma) used in the Bible? The fact is that the Scriptures often use the words “soul” and “spirit” interchangeably. In John 12:27, Christ says, “Now My soul has become troubled.” However, under very similar circumstances in John 13:21, Jesus “became troubled in spirit.” Both terms are used of saints in heaven. In Hebrews 12:23 we read of the, “spirits of the righteous made perfect.” But in Revelation 6:9 we see the, “souls of those who had been slain because of the word of God.”
The trichotomists believe that a person’s soul is composed of their intellect, emotion, and will. The spirit is what they claim communicates most directly with God in prayer and worship. However, these distinctions are entirely foreign to the Biblical text. Everything that the trichotomists say the soul does the Bible says the spirit also does, and everything the trichotomists say the spirit does the Bible says the soul does as well!
The trichotomists teach that our intellect is part of our soul, but in Mark 2:8 we read about Jesus, “perceiving [Gk. epiginosko, literally ‘knowing’] in his spirit” [ESV] and Paul declares in I Corinthians 2:11, “For who among men knows the thoughts of a man except the spirit of the man which is in him?” The Bible says that the spirit can experience emotion just like the soul can. One can have a “downcast spirit”, which is the opposite of a “cheerful heart” (Proverbs 17:22). In Acts 17:16 Paul’s, “spirit was being provoked within him” and in John 13:21 Jesus,”became troubled in spirit.” A person’s will does not exclusively belong to the soul either. Deuteronomy 2:30 says, “But Sihon king of Heshbon was not willing for us to pass through his land; for the Lord your God hardened his spirit and made his heart obstinate.” In Daniel 5:20 Nebuchadnezzar’s, “spirit was hardened so that he dealt proudly.” [ESV]
Furthermore, the trichotomists believe that the spirit is the part of us that relates to God most directly in worship and prayer. In the Bible however, we see that our souls can pray and worship God as well: “To You, O Lord, I lift up my soul.” (Psalm 25:1) “My soul is crushed with longing after Your ordinances at all times.” (Psalm 119:20). Our souls can also pray directly to God, as when Hannah says, “I have poured out my soul before the Lord.”
We can conclude that not only is there no Scripture that teaches trichotomy, but the testimony of God’s word seems to affirm dichotomy. The terms “soul” and “spirit” are used interchangeably, and there is no verse that warrants splitting them into two different elements.
Even though man is composed of two parts, a material element and an immaterial element we must, however, emphasize the overall unity of man. As Wayne Grudem remarks, “In fact, we should not slip into the mistake of thinking that certain activities (such as thinking, feeling, or deciding things) are done by only one part of us. Rather, these activities are done by the whole person. When we think or feel things, certainly our physical bodies are involved at every point as well. Whenever we think we use the physical brain that God has given us. Similarly, our brain and our entire nervous system are involved when we feel emotions, and sometimes those emotions are involved in physical sensations in other parts of our bodies. This is just to reemphasize what was said at the beginning of our discussion, that the overall focus of Scripture is primarily on man as a unity, with our physical bodies and the nonphysical part of our persons functioning together as a unity.”
This is why death is such a tragic and disturbing reminder of the fact that we live in a fallen world. A person’s body and soul/spirit were never meant to be separated, and one day God will join them back together.
(3) THE ARGUMENTS FOR TRICHOTOMY EXAMINED:
Even though the testimony of Scripture is in favor of dichotomy, there are a couple of texts that the trichotomists use to try and prove their theory. We will now examine a few:
I Thessalonians 5:23
“Now may the God of peace himself sanctify you completely, and may your whole spirit and soul and body be kept blameless at the coming of our Lord Jesus Christ.”
Trichotomists insist that since body, soul, and spirit are all mentioned in this verse, this indicates that a man is composed of these three parts. However, if we apply the same hermeneutic to Matthew 22:37, “You shall love the Lord your God with all your heart and with all your soul and with all your mind.” [ESV] then we must believe that our heart and mind are different elements entirely from our soul. This is directly opposed to the trichotomist belief that a person’s emotions and mind are part of their soul! The problem is further complicated by Mark 12:30, “And you shall love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.” [ESV] Should we now add strength to the list of man’s parts? If we interpret these two verses in the same way that the trichotomists interpret I Thessalonians 5:23, then we end up with five or six parts to a man: mind, heart, strength, soul, spirit, and body! Where do we draw the line? It is best to conclude then that in I Thessalonians 5:23 Paul is not dividing a man into three parts, but is rather piling up different synonyms for emphasis, the same way that Jesus did when he listed out heart, mind, strength, etc.
“For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart.”
This verse is not teaching that the Word of God can divide a person’s soul from their spirit, it is simply saying that God’s word can pierce the deepest part of our being. Whether we call it our soul or our spirit, God’s word can penetrate and divide it discovering our deepest thoughts and intentions. Furthermore, it is impossible to divide joints from marrow, because the two are not connected. This further reinforces the idea that the writer of Hebrews is not speaking of dividing soul from spirit anymore than he is about dividing joints from marrow.
Neither of these passages teach trichotomy, and in order for them to speak about trichotomy, a person has to take them way out of context, as well as make a lot of assumptions that simply cannot be found in Scripture.
So why does all of this matter? Is it important whether or not a person believes in trichotomy or dichotomy? While I do not believe that this is a salvation issue, and a person can be a trichotomist and still be a Christian, I believe that this is an important issue that has important implications for our daily lives. Trichotomy can have a dangerous anti-intellectual tendency. If, as the trichotomists say, our spirit is what communicates with God and is separate entirely from our intellect, then there is a tendency to put less emphasis on studying God’s word with our minds and instead rely on messages our spirit has received from God. J.I. Packer warns, “Moreover, [trichotomy] leads to a crippling anti-intellectualism, whereby spiritual insight and theological thought are separated to the impoverishing of both, theology being seen as ‘soulish’ and unspiritual while spiritual perception is thought of as unrelated to the teaching and learning of God’s revealed truth.”
Wayne Grudem also notes, “If we think of our spirits as a distinct part of us that relates most directly to God, we can easily begin to neglect the role of Bible study and mature wisdom in making decisions, and place too much reliance on ‘spiritual’ discernment in the realm of guidance, an emphasis that has, through the history of the church, led many zealous Christians astray into false teaching and unwise practices.”
(1)Trichotomy traces its roots back to Greek philosophy and Gnosticism, and its origins are primarily pagan rather than Christian. Reformed thought has historically affirmed dichotomy, as evidenced in the many Reformed Confessions.
(2)There is no clear evidence in Scripture for the theory of trichotomy, neither is a distinction between soul and spirit such as the trichotomists teach taught anywhere in the Bible, the terms “soul” and “spirit” being used interchangeably.
(3)Trichotomy has a dangerous anti-intellectual leaning, and can sometimes undermine the importance of sound doctrine and careful exegesis of God’s Word.
Contrary to what some people might insist, the debate between trichotomy and dichotomy is not theological hairsplitting. As demonstrated above, this doctrine has important implications for our lives, and a vigorous study of the Scriptures on this subject would be good for all of us.
There is some variation among the sundry trichotomists. In this article I am merely arguing against the more general principles of trichotomy.
Kim Riddlebarger: Trichotomy- A Beachhead for Gnostic Influences, you can read the full article here: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=1&ved=0CCkQFjAA&url=http%3A%2F%2Fkimriddlebarger.squarespace.com%2Ftheological-essays%2Ftrichotomy.pdf&ei=JdCOUuWANeeY2wWN0oHgCQ&usg=AFQjCNFH6SmorjRfIg_MWMYRcyb1aEg0kg&bvm=bv.56988011,d.b2I
 Louis Berkhof: Systematic Theology
John Calvin: Institutes of the Christian Religion 1.15.2
Belgic Confession, Chapter 37
Westminster Confession, Chapter 32.1
All Scripture quotations are from the New American Standard Bible unless otherwise indicated
Wayne Grudem: Systematic Theology, I would strongly recommend reading Grudem’s arguments against trichotomy, found in chapter 23
J. I. Packer: Concise Theology
Wayne Grudem: Systematic Theology