Reductio ad Absurdum

Curious what reductio ad absurdum actually refers to? Essentially, it involves disproving someone’s argument by showing that it is absurd when it is followed through to its most logical conclusion. This indicates that the argument is ridiculous, but it only works as an argument type if the other person’s reasoning is faulty in some way to begin with.

LiteraryDevices.net defines the term as “a Latin term that means “to reduce something to absurdity.” It is a figure of speech that is defined as a manner of arguing something for one’s own position by showing the absurdity of the position of his opponent.”

When it comes to informal logic and argumentation, it is a method of refuting someone’s claim by extending the reasoning beyond the other person’s point and into a position of absurdity. You can also hear this term referred to as argumentum ad absurdum or reductio argument.

What is Reductio Ad Absurdum?

Reductio ad absurdum can also refer to an argument in which something is proved correct by showing the opposite is not valid. This is also known as classical reductio ad absurdum, indirect proof, or proof by contradiction.

Arguments related to reductio ad absurdum are often used to prove math theorems and call the arguments proofs by contraction. The reason this name is used is because math reductio arguments can lead to contradictions. Since a contradiction cannot be true, this makes for a strong reductio argument.

As with any argument strategy, this once can also be abused or misused. However, that doesn’t mean it is fallacious or faulty reasoning. The slippery slope is a similar type of argument that takes reductio ad absurdum to a new extreme and is much more likely to be fallacious.

A slippery slope argument assumes that for something to be accurate, it has to be true in each and every situation. Examples of this include things like:

• If you don’t finish your homework, you will fail the class, which will lead to not graduating, which means not getting into college, never getting a good job, and ending up destitute and homeless.
• If you eat a slice of pizza while on a diet, you will eat one the next day or even several slices. If this continues, you’ll be eating donuts and cookies every day, and the diet will fail and you will gain tons of weight.

These arguments move away from the actual issue to an outcome that may or may not actually occur. It is typically used to appeal to people's fears and emotions.

Examples of Reductio Ad Absurdum

As we established, the reductio ad absurdum argument looks to show something is true, so something else is not. This can be useful in some situations, but not all of them. In math, it makes sense as contradictions cannot exist, but it can also be pushed to a point where the argument does not make a lot of sense.

Some examples of this type of argument include the following:

• Society has to have laws, or else there would be nothing but chaos.
• Trees have weight, but if they did not, they would float around in the sky.
• Football players can sustain injuries and should not play, so other athletes should give up their sports since they are not immune to danger.

Essentially, when someone says that denying a claim leads to an absurd situation, it’s a reductio ad absurdum argument. It puts forth an assumption and then shows how a contradiction to the assumption would lead to absurdity. This is a standard tool used when making an argument, but it can also be misused.

The idea if that is someone can show that a belief leads to something absurd, the belief is not true.

For example, if someone believes being outside with wet hair causes a cold, the belief could be attacked by showing that if being outdoors with damp hair caused colds, it would also be caused by swimming outdoors. It’s clear that this is an absurd idea, so it is also considered ridiculous that getting a cold from being outdoors is believable.

How to Evaluate a Reductio Ad Absurdum Argument

This argument looks to show that an individual claim is false because another claim related to it is absurd. But how do you evaluate the argument itself? It all boils down to answering a few questions.

• Is the second claim actually absurd?
• Does the first claim imply that the second claim would be valid?
• Can the first claim be changed in some way that no longer implies the second claim is true?

If the answer to question one or two is no, the reductio fails. If the answer to one and two are yes, but two is no, then the reductio is likely to be a shallow argument. If the answer to each of the above questions is no, then it is a solid and successful argument.

When this kind of argument is misused, it’s often when used by politicians who are looking to misrepresent what an opponent is saying in order to make another point entirely.

This often turns into a straw man argument, which means an opponent tries to look as if they are refuting an opponent’s argument, when instead, they are refuting an entirely different argument entirely. Misrepresenting an argument can make it easier to attack and make some other type of statement.

Reductio ad absurdum is a valid type of argument, but only if used in the proper manner. Have you ever experienced an argument using this type of logic? Let us know more about it below!