5 Fallacies You Need to Know!

September 4, 2013 | 7 comments

The word fallacy comes from the Latin word fallacia, which could be translated as “deception.” A fallacy is a misleading or unsound argument that can be either accidental or intentional.

To demonstrate five common fallacies, I’d like to propose a deductive argument (if you don't know what a deductive argument is, click here):

Premise 1: Jesus Christ established a church.
Premise 2: The only church that can trace its roots back to the time of Jesus and the apostles is the Catholic Church.
Conclusion: Therefore, Jesus Christ established the Catholic Church.

Now I will offer five fallacious replies, explain why they are fallacious, and show how one ought to respond.

1. Red herring: The person making the argument raises an irrelevant issue to distract the attention of his opponent or audience.

Example: "How can you believe that the Catholic Church is the Church Jesus Christ established in light of the recent sex abuse scandal?"

Response: The sex abuse scandal is an important topic, which I’d be happy to discuss in a later discussion, but it has nothing to do with whether Jesus Christ established the Catholic Church. Let’s stick to the argument at hand.

2. Ad hominem (from the Latin: “to the man”): The person hearing the argument rejects the argument because of the one making the argument.

Example: "You argue that Jesus Christ established the Catholic Church, but the last time I checked you were neither a biblical scholar nor a historian."

Response: You are right, I am not a historian, nor am I a biblical scholar. So what? I may also be obnoxious, arrogant, and smelly. None of that means my argument is unsound. Let’s focus our energy on the argument I’ve offered.

3. Non sequitur (from the Latin, “it does not follow”): The person making the argument draws a conclusion that does not follow from his premises.

Example: "Jesus Christ was perfect, but some popes who have reigned over the Church have been corrupt; therefore, Jesus Christ did not establish the Catholic Church."

Response: The conclusion does not follow from the premise. While it’s true that all popes, because of original sin, are sinners—the first pope, St. Peter, denied our Lord three times—this does not disprove the Church’s divine origin.

4. Genetic fallacy: The person making the argument tries to invalidate a position based on how that position originated.

Example: "The only reason you are making this argument is because you were raised Catholic. If you had been raised in the Bible Belt, you would have been Protestant."

Response: Although it’s true that a person may come to hold a belief for inadequate reasons, this does not mean that the belief is false.

5. Straw man: The person making the argument misrepresents his opponent’s position in order to refute it.

Example: "Just because the Catholic Church is the largest denomination in Christendom, that does not mean Jesus Christ established it. Islam is the second-largest religion in the world and may one day have more followers that the Catholic Church. Wouldn’t that then make Islam the true religion?"

Response: I did not say that Catholicism is true because it has more adherents than all Protestant communities combined. Rather, I proposed that Jesus Christ established a church and the Catholic Church is the only church that dates back to the time of Christ; therefore, Jesus Christ established the Catholic Church.

Join the Conversation

In your experience what is the number one logical fallacy you encounter?

How have you responded to these fallacies in the past?


Matt Fradd is Australian by birth and Catholic by choice. After experiencing a profound conversion at World Youth Day in Rome in 2000, Matt committed himself to inviting others to know Jesus Christ and the Church He founded. As a missionary in Canada and Ireland, Matt proclaimed the Gospel to over ten...

How to Win an Argument Without Losing a Soul
Whether you’re arguing with family members or Facebook friends, skeptical co-workers in the office or pushy proselytizers at your front door, it helps to have not only the facts but the skills for presenting your points forcefully and well. And just as important is your demeanor. For it’s all too easy to beat someone over the head with flawless logic—and turn him off to the truths you’re trying to share. In How to Win an Argument Without Losing a Soul, Matt Fradd equips you with the powers of argumentation you need to be an effective debater and the right attitude for doing it with charity, humility, and patience.

Comments by Catholic.com Members

#1  Gabriela Peixoto - Haverhill, Massachusetts

Wonderful article.
Being a college student, I always encounter souls that are very outspoken in their disdain for the Church. Always good to be prepared with logical, accurate, efficient answers.

September 4, 2013 at 10:45 am PST
#2  theresa thmpson - edmonton, Alberta

when you look back thru history, you have to admit that the RC Church has to belong to Jesus Christ because no other government or institution has SURVIVED like it for 2000 years. :)

September 5, 2013 at 4:41 am PST
#3  Noel Christian Juta - Floridablanca, Pampanga

Oh truly! Fallacies of different denominations are so rampant here in the Philippines. They do it with no ethical values at all.

I have encountered many kinds of fallacies from all sorts of non-Catholic christians. Born-Again christians, Iglesia Ni Cristo, United Methodists, different Baptists, Feminist Church of God, and so on.

The number one fallacy is that Catholics worship saints, Mary, and the images and statues. I responded with my humble knowledge as a layman who studied in a catholic highschool, without a knowledge in apologetics.

September 6, 2013 at 4:50 am PST
#4  David Fritz - Northampton, Pennsylvania

Non Catholics I believe, love fallacies in a self subliminal way or..??? They won't admit it but I think they don't want to get very close to Jesus the same way as we Catholics do."""" If I would,OMG,what would my friends think of me? They will think I'm a homosexual bigot or a right wing racist conservative hell bent on impeaching Obama and a holy roller that's gotta go to churchy every Sunday. I just cant put my self through all that so I'll be happy being a quiet, discreet,by faith alone Christian until I'm raptured up to meet the Lord in the air. The best thing for those folks is "CONFESSION" and the Sacrament of Penance.Those alone with a basic christian belief would cause any man or woman to fall in love with Christ/Catholic Church and want them to convert and come very close to Jesus.Until they experience those beautiful words "I absolve you of your sins" let them know how filled with peace and joy of being renewed again "born again" you could say.Pray to God that they will come to know the fullness of our Catholic faith. I do believe they are worthy of salvation though if they are living out the true meaning of being Christian.

September 8, 2013 at 11:43 pm PST
#5  Sophia Stone - New York, New York

Noel Christian Juta,

"The number one fallacy is that Catholics worship saints, Mary, and the images and statues."

Actually, they are committing the informal fallacy, straw man. The Roman Catholics are claiming that Mary should be worshiped, but some born-again christians are misrepresenting the claim as, "Catholics believe that Mary should be worshiped."

Informal fallacies have particular names. You need to search the list of fallacies and see which fallacy your example falls into.

September 9, 2013 at 1:26 pm PST
#6  Michael Rogala - Chicago, Illinois

The Number 1 fallacy is that the "apologists" on this site don't have their head where it is dark and warm.

The only author I have hit so far who made a cogent and articulate case is the Director, Keating. It is not important whether one can agree or disagree with a given position, but whether or not the argument makes sense at some level whether you agree with it or not.

For the most part I have not found that here.

August 11, 2014 at 5:06 pm PST
#7  Harry Ehmann - Bedford, Texas

And thanks to Michael for a good example of the Ad Hominem argument. But "making sense" is subjective. Or doesn't that make sense?

September 24, 2014 at 9:38 am PST

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