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:
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.