Logic is a study of the laws of reasoning, and Christ is the lawgiver. We will see this by considering how Christ is Lord over terms, statements, and arguments.

Terms are the verbal expression of ideas, or more concretely, names of things. Col. 1:16 says that “All things were created by Him and for Him.” By His word things are what they are. When we are defining terms and relating terms to each other, we are defining things that Jesus Christ has made, things that He cares about. Jesus created marriage. Does He care how we define marriage? Jesus created people. Does He care if we define a fetus as a person?

It follows that Jesus cares whether or not our definitions are good. If they are not, then we are not speaking of things as Christ made them. Logic teaches laws for defining terms, such as “the definition must state the essential attributes” and “the definition must not use words that are unclear.” Where do these laws come from? They are basically applications of the law of God: be honest, be helpful, love your neighbor as yourself.

Statements are claims to truth. Jesus is “the Way, the Truth, and the Life” (John 14:6), who is “full of grace and truth” (John 1:14). Truth is what God knows, that which corresponds to who He is and what He has made. God wants us to distinguish between truth and falsehood. Is it true that God has commanded all men everywhere to repent? Is it true that a husband should love his wife? Popular culture makes a lot of claims about how to know truth. Is it true that you are sitting in that chair? Really true? Do you think that’s air that you are breathing? Or is truth “simply electrical signals interpreted by your brain?”

When we are teaching students how to know the truth of statements, we are helping them to know more of who Christ is, what He really has done and is doing in the world, and what He wants us to believe.

Christ is Lord over arguments. Arguments are one means by which we come to know truth as truth. There are other means by which we know truth, including statements made by true authorities, such as the Bible. But God has given us the ability to reason in order that he may use our reason to lead us to truth. God has given us minds that reason so that we can receive His word, understand it, and apply it.

Much of the year in a logic class is spent learning rules for determining if an argument is valid or invalid. Consider this argument: “If you are a Christian, then you should read the Bible. You are a Christian. Therefore, you should read the Bible.” This is a valid argument. If the premises are true, then you must accept the conclusion as true. But where does the strength of that word “must” come from? Where do I get the authority to say that you must do something here? I would again argue that this is an ethical “must.” God has made words, and the logical reasoning carried across by those words reflects His rational character. “You must accept this as a valid conclusion” means that, if the premises are true, a denial of this conclusion is dishonesty, a rejection of how God has made the world and of who He is. In his book The Doctrine of the Knowledge of God, John Frame says, “The logical ‘must’ indicates a moral necessity. To say that someone ‘must’ accept a conclusion is to say that he ought to accept it, that he has an obligation to accept it.”

Consider this argument: “If you are a Christian then you must read the Bible. My Mormon friend reads the Bible. Therefore my Mormon friend is a Christian.” This is an invalid argument. Even if the premises are true, I am under no obligation, ethical or otherwise, to accept the conclusion as true. It would in fact be wrong for someone to require that I accept that conclusion based on that argument alone.

This question of right or wrong, true or false, correct or incorrect, comes down to a question of recognizing how Christ has made the world, and who He is. These examples should suffice to show how the laws of Logic reflect something about Christ’s laws of love, honesty, and truth.