3 Final Logical Fallacies to Avoid (and How to Tell When Someone Else is Committing Them)

[This is the final post in the series on Logic and Apologetics]

  1. Begging the Question—assuming a conclusion to be true without proving it. If I am trying to prove that people have lost the ability to distinguish between right and wrong by citing increase numbers of adulterous affairs and abortions, I am assumingadultery and abortion to be wrong, when I should have to arguethat they are wrong. Even though adultery and abortion are wrong, rising incidents of each does not necessarily prove that people have lost the ability to distinguish right and wrong.

How Christians do this:

“I believe the Bible is the Word of God because I just know it to be so.”

“Evolution cannot explain the origin of life on earth, because it is not true.”

How unbelievers do this:

“Science has disproved the existence of God because there is no scientific evidence for God.”

“Jesus cannot be the only way to be reconciled to God, because that would mean all other religions are wrong and most of the world would be condemned.”

  1. Faulty Analogy—making a comparison between two things that are not similar. An analogy allows us to explain one thing by comparison to another. But every analogy breaks down at some point and some things bear no similarity with other things. If I compare the gentleness of a mother with her baby to a nuclear explosion, there is little chance that the analogy will be helpful in any way.

How Christians do this:

“The Trinity is like an apple (or an egg, or water, or a three-leaf clover).”

“If a person is spiritually dead then I won’t bother sharing the gospel with him because dead people don’t hear you when you talk.”

How unbelievers do this:

“Christians used the Bible to support slavery and they were clearly wrong, so when they use the Bible to condemn homosexuality, we can clearly see they are wrongly using the Bible again.”

“Our genetic code is ‘selfish’ and blindly strives to reproduce itself for survival.”

  1. Equivocation—when a word or phrase is used in more than one sense or its meaning changes in the middle of an argument, a dialogue descends into confusion. If I ask my teenager to clean his room and we have two different ideas of what “clean” means, the communication will fail.

How this confusion happens:

Skeptics love to define faith as “belief despite the lack of evidence,” but that is not what Christians mean when they use the word. By “faith” a Christian means trust in God’s revelation. If a skeptic says, “I have evidence and you have faith,” I must correct his erroneous understanding of faith or we will never get anywhere in the discussion.

Similarly, evolutionists often use the word “science” when in fact they believe in scientism(the only things that exist are physical objects and natural, not supernatural, forces guide everything apart from a divine intelligence). If we do not expose the difference, we will find ourselves arguing against science when we have no misgivings about real science.

Hopefully this explanation on logical fallacies has helped you notice some fallacies in your own thinking, as well as building discernment for identifying in the arguments of unbelievers. Skill in detecting logical fallacies takes time and much practice. If you are thinking carefully and critically, however, you will begin to spot fallacies and be able to dismantle them in order to help another person see the truth more clearly.

A Little Note on Logic

Logic is not the final arbiter of all things true, for several reasons. First, flawed and finite people use logic. That means that while logic may help to ensure we arrive at consistency, the premises upon which logical argumentation are built are sometimes disputed. Two rational people can disagree about a premise because even statements of fact are often values-laden. That is, we don’t have a God’s-eye-view of reality without having to interpret what we see. Our own biases, limitations, and errors can creep into our thinking.

Second, logic flows form the character of God. Logic does not stand over God, and therefore some things will not seem logical, even though they are true. 


Christians do not need to resort to logical fallacies, because the Christian faith is the summit of wisdom and rationality. To believe and argue logical fallacies demeans and diminishes the true logic of the gospel. Paul states this clearly in 2 Corinthians 4:3-6 where Jesus is presented as the wisdom of God:

And even if our gospel is veiled, it is veiled to those who are perishing. In their case the god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the image of God. For what we proclaim is not ourselves, but Jesus Christ as Lord, with ourselves as your servants for Jesus’ sake. For God, who said, “Let light shine out of darkness,” has shone in our hearts to give the light of the knowledge of the glory of Godin the face of Jesus Christ.

Everything pursued by the major cultures of the first century Western world was found in Christ. The Greeks sought the light of wisdom, Jews sought knowledge, and the Romans sought glory, and yet each of these is embodied in the message of Jesus. To seek these things apart from Christ is futile, and to claim to have obtained them apart from Christ requires irrationality and contradiction.

Paul also reminds us that the wisdom of God is wiser than the greatest of “human” wisdom that contradicts it (1 Cor. 1:20-25). This does not mean that unbelievers are not or cannot be brilliant in many areas of human achievement. Some of the brightest scientists, philosophers, engineers, writers, and so on have rejected Christ. It does mean, however, that they can never understand the whyof the knowledge they possess. They can never know the purpose for which they and their expertise exist. They can never understand the infinitely glorious spiritual realities of God’s world until they are transformed by Christ. To make sense of the world they must devise strategies and explanations fraught with logical fallacies. These strategies “work” for them, but they are not the truth. Our prayer is that the Spirit of God will give sight to their blind eyes, abandon their resistance to the gospel built on their fallacies, and see clearly the wisdom and rationality that is Christ.

3 More Logical Fallacies to Avoid (and How to Tell When Someone Else is Committing Them)

red herring[This post continues the series on Logic and Apologetics begun in previous posts]

Logical fallacies are flaws in reasoning that superficially seem to be sound, but upon examination are found to be false. The power of logical fallacies is that even after they have been shown to be flawed, they still retain their power to convince because they are often emotionally satisfying.

  1. Red Herring—an argument that seems to support a person’s position, but in reality, has nothing to do with the question at hand. The name of this fallacy is derived from the practice of dragging a bag of red herring across a scent trail, so dogs would be distracted and lose the scent. When the question at hand is ignored and a related idea is argued instead, a red herring has been committed. This is a difficult fallacy to spot. We must always fight mental confusion and drift to maintain clarity on what the real issue is.

How Christians do this:

“It doesn’t matter that there are so many religions in the world. Christianity is still the truth. You don’t have to eat all the different kinds of cereals at the grocery store to have a favorite.”

“If the Bible is not true, then you must be saying that my grandparents were wasting their time when they read a Bible verse each day of their lives.”

How unbelievers do this:

“How can Christianity be true when there are so many more ways that the church could be helping the homeless?”

“I know God is not real, because I asked him to show himself to me in some way and he didn’t.”

  1. False Dilemma—only two choices are offered when, in fact, there are more options available. Almost always one option is too distasteful to accept, so the listener is forced into a choice he does not want to make.

How Christians do this:

“Ask Jesus to be your Savior right here, right now, regardless of your questions and objections, or you can count on the fact that you will never get into heaven.”

“Either you believe in a literal 24-hour, six-day creation or you cannot become a Christian.”

How unbelievers do this:

“Either you believe in science and reject religion, or you must remain in blind superstition and reject modern science.”

“Either God is not all-powerful, or he is not all-loving. If God were all-loving, he would want to rid the world of evil. If he were all-powerful he would be able to get rid of evil in the world. But there is evil in the world, so either God is not all-powerful or not all-loving.”

  1. Hasty (or Unwarranted) Generalization—a conclusion about everything of a particular kind based on one or a few examples. For example, when we judge all car salesmen based on our experience with one or two of them, we commit hasty generalization. We tend to believe that every individual person, thing, or idea is just like the few we have encountered, heard about, or read about online.

How Christians do this:

 “Atheists are dangerous and immoral people. I know; my neighbor is an atheist, and he has skull tattoos and yells obscenities at his live-in girlfriend.”

“Muslims will never listen to the gospel. Look at how they persecute Christians around the world.”

“Nobody wants to hear the gospel anymore. I have tried witnessing to my coworkers, and they just shut me down and refuse to talk to me about God.”

How unbelievers do this:

“Christians are dangerous to society. That last shooting was carried out by someone who went to church.”

“Churches are all about guilting people into giving their money in exchange for heaven. I visited a church once that took two offerings in one day and the pastor was preaching on money.”

“Fundamentalists are intolerant of other religions.”

In the next post we will conclude this series on logic and apologetics.

3 Logical Fallacies to Avoid (and How to Tell When Someone Else is Committing Them)

Head in Hands[This post continues the short series on Logic and Apologetics posted previously.]

So far, we have looked at the basic structure of logic. Errors in the structure of logical arguments are called formal fallacies. For the sake of brevity, we don’t cover them in this book. Rather we move on to the most common mistakes in informal logic known as logical fallacies. These are flaws in reasoning that superficially seem to be sound, but upon examination are found to be false. The power of logical fallacies is that even after they have been shown to be flawed, they still retain their power to convince because they are often emotionally satisfying.

For example, many Christians believe the following statement to be true, even though it is a fallacy, because it gives them confidence: “Millions of people around the world and throughout history have found peace and hope in Jesus, therefore he must be the way to salvation.” While it is true that becoming a follower of Christ gives peace, that truth does not prove Christianity true. People feel a sense of peace through many means—other religions, no religion, meditation, addictive substances, catching a great wave, or a hike in the woods. This fallacy is called Appeal to Popularity, an argument based on what a large number of people think or believe. It reminds us that nothing is ever true just because it is popular or the majority position.

What follows is a short list of some popular logical fallacies that both believers and unbelievers tend to use in support of or opposition to the Christian faith. I will explain each one,[1]show examples of how both groups argue the fallacy, and then show what is wrong with both. This exercise should help us see that we need to present our reasons for what we believe in true and valid ways. Many of these fallacies have Latin names (post hoc, ad hominem, tu quoque), but for the sake of simplicity I have listed their common English names.

  1. Appeal to Authority—a claim is defended or advanced on the basis of those who believe it. While we may appeal to the arguments of experts in a particular field, just because recognized experts advocate or deny a position does not make it true or false. Nothing is ever true because of who said it, except God.

How Christians do this:

“Einstein believed in a higher being, and he was the smartest man in the 20thcentury, so you should too.”

“Billy Graham spoke to more people than any other evangelist in history, and everywhere he went people were converted, so that shows that the gospel is the truth for every person in the world.”

How unbelievers do this:

“93% of members of the National Academy of Science do not believe in God, so it is not reasonable to believe in God”—Richard Dawkins

“Bart Ehrman is a New York Times Bestselling author, a world-renowned professor at the University of North Carolina, and a graduate of Moody Bible Institute, and he says the manuscripts of the New Testament were corrupted, so it must be true.”

  1. Personal Attack—ignore the argument and criticize its author. Accusing the other person of being unreliable, ignorant, or lacking expertise says nothing about the validity of her argument, but it can have a strong emotional impact on listeners. This fallacy is a form of dishonesty because it distracts from the real issue at hand by focusing on something that has nothing to do with the argument, whether true or false.

How Christians do this:

 “Mormonism cannot be true. Look at the life and crimes of Joseph Smith!”

“How do you knowevolution is the way the world came about? Are youa scientist?

“Bill Nye only has an undergraduate degree in engineering, therefore he doesn’t know anything about biology or cosmology.”

How unbelievers do this:

“Ken Ham only has an undergraduate degree in applied science, so what could he know about advanced science?

“If Christianity was true then Christians would not be such hateful, bigoted, racist people.”

“The disciples were uneducated fisherman, so their ‘eyewitness testimony’ about Jesus’ resurrection was nothing more than hallucination and superstition.”

  1. False Cause—attributing a cause to an event or idea that is not the actual cause. Just because it rains every time you bring Sally with you on a picnic does not mean that Sally causes the rain. Just because your favorite baseball team wins whenever you are in your lucky chair wearing your lucky socks and eating pretzels does not mean that you are causing the wins with your actions.

How Christians do this:

“Attending public school makes teens more likely to walk away from their faith in college.”

“This nation started going downhill when prayer and Bible reading were taken out of schools.”

“The reason crime is on the rise is because people have stopped going to church.”

How unbelievers do this:

“As church attendance falls, violent crime declines; therefore, the faster we get rid of superstitious notions of God, the more peaceful our society will become.”

“Schools that teach children that they are good, and not sinners, have lower rates of failure.”

“Science flies you to the moon; religion flies you into buildings”—Physicist Victor Stenger

It is clear so far that believers and unbelievers alike can commit logical fallacies. In the next post we will look at 3 more logical fallacies that can arise in an apologetic discussion.

[1]Adapted from Stephen S Carey, The Uses and Abuses of Argument (Mayfield Publishing Company, 2000).

Using Logic in Apologetics

invisibleIn a previous post we introduced the basics of logic. Here we see how logic is used in apologetics encounters.

When we apply the science of arguments to apologetics, it is clear that the arguments used against Christianity are often stated informally. The informal statement “I don’t believe in God because I can’t see him” can be written into a formal syllogism such as:

P1: I must see something to believe in it.

P2: I don’t see God.

Conclusion: Therefore, I don’t believe in God.

Notice that Premise 1 (P1) is not stated explicitly in the informal statement, but it is implied. This is where questions are so important in conversations about the gospel. I would not know the reason for someone’s rejection of God unless I asked. Once someone tells me they don’t believe in God because they feel they must see something to believe it, I am able to construct the syllogism above. I can now see his argument clearly and can address it.

In this case the informal statement, “I don’t believe in God because I can’t see him” is an incomplete syllogism. When a syllogism is incomplete, it is called an enthymeme. The challenge of identifying logical problems in an argument is the difficulty of taking the enthymeme as it is stated and filling in the missing terms, so the complete syllogism is clear. This takes time and practice, but eventually you will begin to be able to identify the unstated assumptions of a conversation partner (or yourself!).

In fact, a number of additional premises could be inferred from such a statement, depending on the context of the conversation. For example:

P1: It is not rational to believe in something that cannot be scientifically proven.

P2: I am a rational person.

Conclusion 1: I will not believe in something that cannot be scientifically proven.

P4: There is no way to scientifically prove God.

Conclusion 2: I will not believe in God.

When you begin to see more detail in the unbeliever’s argument, you can break it down and deal with the component parts.

First, we can challenge the unbeliever regarding P1: “Why do you believe that it is not rational to believe in something that cannot be scientifically proven? What about things that all rational people believe in such as the laws of logic and human memory? Where do you get your definition of rationality? What about the limitations of science, such as arriving at wrong conclusions or its inability to explain some things that happen in the natural world?”

Second, we can applaud the unbeliever in her desire to be rational (P2). We can point out that Christianity is deeply concerned about being rational and basing its beliefs on historical events.

Third, as a result of the problems with P1, we can show her that Conclusion 1 she already believes things that cannot be scientifically proven.

Fourth, P4 is not a problem, since we have already established that we can know certain things without proving them scientifically.

Fifth, now that we have challenged the premises that make up this argument, we can challenge the unbeliever to reconsider her rejection of God.

You can perhaps already see how important and powerful logic is in apologetics. Logic is how we see through the objections and challenges to the Christian faith. It is also how we dismantle the arguments of unbelievers and show them the logic of rationality of the gospel of Jesus Christ (2 Cor. 10:3-5). Jesus is the ultimate logic in the universe as John tells us when he describes Jesus as “the Word” in John 1:1-4, 14. The Greek word for “Word” is logos, from which we get the word logic. The Greeks believed that the Logoswas the ultimate rationality in the universe that unified and upheld all that existed. John makes a radical statement when he says that the Logosis both God and became man. That is why it is important for Christians to think and argue logically, because when we do, we reflect the wisdom of Christ.

In the next post we will examine types of arguments in order to help us reason more clearly and with validity in our Christian apologetic.

Basic Logic for Apologetics

logic lightbulb

“Christianity is just not logical!”

A friend of mine who serves in Spain began to encounter this objection when he tried to talk about faith in Jesus Christ. He wrote to me and asked how he could respond. To commit your life to something that is illogical is a serious charge. If Christianity is truly illogical it calls into question how we can expect modern people to believe it. Even more, it raises the question of how we can believe it ourselves. Is the gospel truly against logic?

The answer lies in the nature of logic itself. Logic is one of the powerful tools of apologetics. Logic has the power to expose contradictions in both our thought and the belief systems of unbelievers. Christians are often viewed as illogical and irrational by unbelievers who put great emphasis on rationality, logic, and scientific precision. While it is true that Christians can be illogical and irrational, the Christian faith is neither of these things. The Christian faith is the only belief system that truly reflects the nature of the world and truth as it is. All other belief systems are denials or distortions of the truth.

One of the most powerful ways to defend the Christian faith is to identify and refute logical fallacies in the objections raised against the Christian faith. This requires, first of all, that our own reasoning is marked by true and sound thought. In this chapter we will learn the basics of logical thinking and how logic can help us see through the false beliefs of unbelievers we meet.

The Basics of Logic

Logic is the art and science of reasoning well. More formally, it is “the study of the methods by which the conclusion is proved beyond all doubt.”[1]In other words, logic is what distinguishes between what is not true, what may be true, and what is necessarily true, given the facts. Logic helps us avoid contradiction and irrationality. It also keeps us from allowing incidental or unimportant factors from interfering with our quest for the truth. For example, whether I like something or not, if it is true, I should believe it. Whether I like the person who is telling me a fact, if the fact logically follows from the evidence, I should believe it.

The Elements of Logical Argumentation

To ensure that our thinking is logical, we must understand the basics of logical argumentation. First, the most basic building block of logical thinking is a sentence. A sentence is a complete grammatical thought. Sentences can be short, such as, “Run!” or “Will you?” As long as a subject and verb are present in the proper relationship, you have a sentence.

proposition or statement, on the other hand, is a sentence that affirms or denies something, and can be true or false. “God exists” and “The universe is not eternal” are both propositions that can be used as part of an argument. A syllogismis a kind of logical argument in which one or more propositions are combined to result in a conclusion, or inference. When propositions are used in a syllogism, they are called premises.

An argument consists of at least one syllogism, and often several syllogisms strung together. An argument “is what results when someone advances a claim or series of claims as evidence for the truth of another claim.”[2]What we seek to present in apologetics are arguments that persuade unbelievers toward the truth.

So, to summarize, an argument is a claim for truth and consists of one or more syllogisms, in which the conclusion necessarily arises from the premises.

For example, here is an example of a famous syllogism:

Premise 1: All men are mortal.

Premise 2: Socrates is a man.

Conclusion: Socrates is mortal.

This syllogism consists of two premises that necessarily result in the conclusion (inference). In a syllogism, the truth of the premises is assumed to already be established. If it is true that all men are mortal, and that Socrates is a man, then it necessarily follows that Socrates is mortal.

Even though such words are not used in the example above, sometimes connecting words are used to show more clearly the necessary nature of the conclusion. For example, the conclusion could read, “Therefore, Socrates is mortal,” or “Because all men are mortal, and Socrates is a man, consequently, Socrates is mortal.” Connecting words such as “thus,” “because,” and “therefore” don’t always show up in formal syllogisms like the one above, but we do tend to use them when we speak.

In normal conversations people don’t speak in syllogisms.  They don’t say, “Premise 1: Ice cream costs $4.00. Premise 2: I have $4.00. Conclusion: I have enough money for ice cream.” Rather, we tend to think informally and arrive at such conclusions without working through the logic explicitly in our heads.

In the next post we will look at the value of logic for apologetics.

[1]Gordon Clark, Logic(Trinity, 1988), 1.

[2]Stephen Carey, The Uses and Abuses of Argument: Critical Thinking and Fallacious Reasoning(Mayfield, 2000), 3.

A Complexity is Not a Contradiction: Jonah and the Whale as an Example

“When dealing with skeptics’ claim of Bible contradictions it seems one can never be reminded enough of what exactly is a contradiction.  A contradiction occurs when two or more claims conflict with one another so that they cannot simultaneously be true in the same sense and at the same time.  To put it another way, a Bible contradiction exists when there are claims within the Bible that are mutually exclusive in the same sense and at the same time.”

Read the full article here: Bible Contradiction Resolved: Who Cast Jonah Into the Sea?.