The Trilemma Argument - Part 1: Analysis of the Logical Structure

INTRODUCTION TO THE TRILEMMA

A central belief of the Christian faith is that Jesus is God incarnate. According to traditional Christianity, Jesus is both fully human and fully divine.[1] A widely known argument for Jesus’ divinity is called the Trilemma Argument.  

The Christian author C.S. Lewis popularized the Trilemma in his book The Case for Christianity, which was later republished in Mere Christianity.[2] The Christian apologist Josh McDowell has restated and developed the Trilemma in his Evidence that Demands a Verdict books and in the recently published book Evidence for Jesus, co-authored with his son Sean McDowell.[3] 

Josh McDowell and his son Sean McDowell present one of the clearest versions of the Trilemma Argument, so I am going to focus on their presentation of this argument in their book Evidence for Jesus.

Here is the reasoning at the heart of the Trilemma Argument:

ONCE I (JOSH) CONCLUDED THAT JESUS CLAIMED TO BE GOD, I realized I only had so many options left. I could reject this claim, which would mean that either Jesus was a liar who knew he wasn't God but said so anyway or a lunatic who believed he was God but wasn't. Or I could accept this claim, which, for me, would mean becoming a Christian. This has famously been called the "liar, lunatic, Lord" trilemma. (EFJ, page 64)

Here is the reasoning of the McDowells in support of the view that we are forced to choose between these three alternatives:

…Jesus’ claim to be God must be either true or false. If Jesus’ claims are true, then he is the Lord…. But if Jesus’ claims to be God were false, then we are left with just two options: he either knew his claims were false (he was a liar), or he did not know they were false (he was crazy). (EFJ, page 65)

THE CORE ARGUMENT

1. Either (a) Jesus lied about being God or (b) Jesus was seriously mentally ill, or (c) Jesus is God.

2. It is not the case that Jesus lied about being God.

3. It is not the case that Jesus was seriously mentally ill.

THEREFORE:

4. Jesus is God.

THE SUB-ARGUMENT FOR PREMISE (1)

8. Either Jesus’ claim to be God was false or Jesus is God.

12. If Jesus’ claim to be God was false, then either (a) Jesus lied about being God or (b) Jesus was seriously mentally ill.

THEREFORE:

1. Either (a) Jesus lied about being God or (b) Jesus was seriously mentally ill or (c) Jesus is God.

 

THE SUB-ARGUMENT FOR PREMISE (8)

5. Jesus claimed to be God.

THEREFORE:

6. Either Jesus’ claim to be God was false or Jesus’ claim to be God was true.

7. If Jesus’ claim to be God was true, then Jesus is God.

THEREFORE:

8. Either Jesus’ claim to be God was false or Jesus is God.

 

THE SUB-ARGUMENT FOR PREMISE (12)

5. Jesus claimed to be God.

THEREFORE:

9. If Jesus’ claim to be God was false, then either Jesus knew his claim to be God was false, or Jesus did not know his claim to be God was false.

10. If Jesus’ claim to be God was false and Jesus knew his claim to be God was false, then Jesus lied about being God.

11. If Jesus’ claim to be God was false and Jesus did not know his claim to be God was false, then Jesus was seriously mentally ill.

THEREFORE:

12. If Jesus’ claim to be God was false, then either (a) Jesus lied about being God or (b) Jesus was seriously mentally ill.

END NOTES

1. Robert Bowman Jr. “Is it Wrong to Say that Christ is Fully God and Fully Man?” (Posted on July 20, 2024, viewed 9/14/26): https://robertbowman.net/2024/07/20/is-it-wrong-to-say-that-christ-is-fully-god-and-fully-man/

2. C.S. Lewis, The Case for Christianity (New York, NY: The Macmillan Company, 1944), pages 44 to 45. This material was later re-published in Mere Christianity (New York, NY: The Macmillan Company, 1952).

3. Josh McDowell has presented the Trilemma in various books. Here are a few examples: Evidence that Demands a Verdict (San Bernardino, CA: Here’s Life Publishers, Inc., 1972), Chapter 7 (pages 107-113); Evidence that Demands a Verdict, Volume 1, Revised edition (San Bernardino, CA: Here’s Life Publishers, 1979), Chapter 7 (pages 103 to 109); The New Evidence that Demands a Verdict (Nashville, TN: Thomas Nelson, 1999), Chapter 7 (pages 155 to 163); Evidence that Demands a Verdict, co-authored with his son Sean McDowell (Nashville, TN: Thomas Nelson, 2017), Chapter 8 (pages 195-204); Evidence for Jesus, co-authored with Sean McDowell (Nashville, TN: Thomas Nelson, 2023), Chapter 8 (pages 64 to 71).