Ten Fallacies Everyone Should Know
Logic is the art of thinking with discipline. Logic teaches us to apply principles of consistency to our thinking so that our argumentation is sound and, therefore, trustworthy. Part of logic is learning to recognize and avoid logical fallacies. A logical fallacy is the use of invalid or otherwise faulty reasoning in constructing an argument that may appear well-reasoned if unnoticed.
Today we are going to take a look at ten logical fallacies that everyone should know. They are regrettably common in society; as you go through this list, think about where you may have seen examples of these in your own experience. Or go through the list with your children and get them talking about places they may have seen these fallacies.
Ad Hominem
The words ad hominem are Latin for “against the man.” An ad hominem fallacy occurs when someone attacks the person making an argument rather than the argument itself. This happens a lot in politics, where a politician will attack his or her opponent personally instead of addressing their policy proposals. It is fallacious because someone’s personal character has no bearing on whether their argumentation is sound.
Straw Man
The straw man fallacy happens when someone attacks a distorted version of an argument that they created themselves rather than engaging in the actual argument. Attacking the fabricated argument gives the illusion of victory when, in reality, the substance of the argument has not been addressed. See our article “Sound Argumentation: The Straw Man vs. The Steel Man” for more on this fallacy.
Appeal to Authority
In this fallacy, someone asserts that something is true merely because it is backed up by someone who is (supposedly) an authority on the subject. It is fallacious because an appeal to authority avoids addressing the argument itself by outsourcing the argument’s soundness to a third party. Remember that authority is not irrelevant in argumentation—when the argument is about what an authority says or thinks. For example, if the argument is “The Church Fathers believed in the Real Presence of Christ in the Eucharist,” then obviously a discussion of the Church Fathers’ views is relevant. However, arguing that the Church Fathers believed something and arguing why we should believe something are two different arguments. While authority can be invoked when it is relevant, it’s no substitute for sound argumentation.
Slippery Slope
A slippery slope fallacy occurs when we take an argument from its first, sensible premise and extrapolate it to an undesirable, extreme conclusion via a series of hastily connected steps. This is also called a reductio ad absurdam, a “reduction to the absurd.” For example, suppose someone argues, “The voting age should be lowered to 17,” to which someone replies, “If we lower it to 17, then 16-year-olds will want to vote, and so on and so on until, before you know it, we’ll be letting 10-year-olds have the vote!” The slippery slope takes a limited premise and extrapolates it universally to draw out a wild conclusion nobody would support. The undesirability of the conclusion is then attached retroactively to the premise.
Bandwagon
The bandwagon fallacy relates to the tendency of people to affirm something as good or true just because it is popular. Humans are social creatures, and the power of group think can exert tremendous pressure on our minds. This is why parents often ask their teens, “If all your friends jumped off a bridge, would you jump too?”
Appeal to Ignorance
This fallacy occurs when someone says an argument must be proven true because it cannot be falsified. Or, conversely, that it must be false if it cannot be proven true. Not all arguments have mutually exclusive conclusions. Just because we know something is not X, it does not follow that it is Y. For example, I cannot prove that I am not trapped in a sophisticated hallucination at the moment, like in The Matrix. But the fact that I cannot prove I’m not hallucinating does not establish that I am.
False Dilemma
This happens when two choices are presented as the only possible options when, in fact, there are others. This line of thinking is fallacious because it fails to see that different premises could account for a greater variety of conclusions. It restricts which premises are allowed to be considered in order to force an artificial dilemma. During the Cuban Missile Crisis, military advisors insisted to President John F. Kennedy that he either had to launch a preemptive military strike against a Soviet missile installation in Cuba or else he was exposing the United States to nuclear attack. The actual solution—using a naval blockade to deter the Soviets from continuing further missile shipments—was not presented.
Hasty Generalization
The hasty generalization happens a lot in social sciences and political polling, where an extremely broad generalization is drawn from a sample size that is far too small. This happens when you see polls arguing that “most Americans” prefer this or that based on a poll of thirty people. In logical terms, the hasty generalization draws distributed conclusions from entirely undistributed premises.
Red Herring
One of the most famous logical fallacies, the red herring, occurs when someone deliberately attempts to move the issue under discussion to a new, irrelevant topic. This distracts from the main argument. For example, suppose a driver gets pulled over for speeding and angrily tells the officer that his time would be better spent chasing dangerous criminals. In this example, the driver is trying to shift the issue from his speeding to how the officer manages his time. The real issue is that the driver was speeding.
Appeal to Tradition
Appeal to tradition is when one argues that something must be good or true because it has been practiced for a long time. The duration of which something has been held or practiced has no bearing on whether it is a sound practice or argument. This is common in large institutions where practices and assumptions have been hallowed by time, and there is tremendous reluctance to change.
Recognizing these fallacies is essential to build up your child’s reasoning powers. Another way to foster sound methods of argumentation in your child is to sign them up for logic classes through Homeschool Connections. We offer a wide variety of logic courses every year, both LIVE and recorded. To learn more, check out this article on HSC’s logic offerings.
What are your thoughts on this topic? Join me and other homeschooling parents at our Homeschool Connections Community or our Facebook group to continue the discussion!