By Ivy Altman
Deductive forms are the building blocks of valid arguments. There are many deductive forms; however, one of the most interesting is Reductio ad absurdum, often reduced to simply “reductio.” The reductio is common and often used in everyday life, but despite this, it is one of the most misunderstood forms, especially in media. In this article I will outline both instances where reductio is used incorrectly, and places that use reductio in an accurate and effective way.
What is the Reductio Ad Absurdum?
While doing my research for this article, I found that reductio ad absurdum is often misunderstood and misrepresented in media. People tend to think that anything absurd is reductio, which is not the case. In many cases, even people who are writing about this form do not understand what it is! Reductio is a variation on the deductive form modus tollens:
If p then q.
Not-q.
Therefore, not-p. (Weston 23)
Reductio is a “reduction to absurdity”. Many people misunderstand this to mean anything and everything absurd is reductio; however, the key to this structure that many miss is assuming the opposite. With reductio, to prove your argument, you must assume the opposite and show it to be absurd, demonstrating that your argument is the only possible conclusion:
To prove: p.
Assume the opposite: Not-p.
Argue that from the assumption we’d have to conclude: q.
Show that q is false (absurd, impossible, etc.)
Conclude: p must be true after all. (Weston 46)
The misuse of Reductio Ad Absurdum in media
Reductio is one of the most common forms found in everyday life; however, many misunderstand it. I came across so many examples in my research in which sources claiming to write about reductio described completely different forms. One example in which reductio is misrepresented occurs in The Dumpling Paradox episode of the Big Bang Theory. In this episode, an argument occurs between the two leads Sheldon Cooper and Leonard Hofstadter over whether they will let their neighbor Penny stay on their couch for the night. When Sheldon argues that they only have enough earthquake kits for two people, Leonard says to Penny that she can stay as long as she doesn’t resort to cannibalism. When Penny is confused by this, Sheldon explains that Leonard “used reductio ad absurdum: the logical fallacy of extending someone’s argument to ridiculous proportions and then criticizing the results.” Unfortunately for Sheldon, he just defined the Strawman Fallacy. Reductio ad absurdum is not a fallacy at all, but rather a valid logical form.
In an article critiquing this very scene I found another error. This article fromSlipups .com states that what Sheldon meant to say was argumentum ad absurdum—which, the entry states, is a logical fallacy, rather than reductio ad absurdum. However, argumentum ad absurdum and reductio ad absurdum are synonymous, referring to exactly the same thing.
Another example of the misuse of reductio is in a Jester Bear article titled Reductio Ad Absurdum and Humor. This article does define the argument type correctly as a form that “demonstrates that a counter argument is fallacious or silly by reducing it to an ‘absurd’ conclusion”—however, the Monty Python and the Holy Grail dialogue that this article goes on to cite as an example follows this form:
If the woman is a witch, she will weigh the same as a duck.
The woman weighs the same as a duck.
Therefore, the woman is a witch.
To be clear, this is not the reductio as the above article claims, but rather the deductive fallacy affirming the consequent:
If p then q.
q.
Therefore, p. (Weston 88-89)
This is an inherently invalid argument. Factual in any way or not, this is not reductio ad absurdum, just an absurd argument.
My favorite instance of the mischaracterization of reductio ad absurdum is a Medium article Reductio Ad Absurdum—The Comedy of Dave Chappelle. This article is so erroneous that it claims five examples of reductio that it explicitly states follow the structure of reductio ad absurdum, and in each case, this claim is completely inaccurate. I will illustrate one. The argument structure is as follows:
If a woman can choose to abort a fetus, then a man should be able to choose to financially abandon his child.
A woman can choose to abort a fetus.
Therefore, a man should have right to financially abandon his child.
This is not even remotely close to the reductio ad absurdum structure. This article confuses someone implying a statement is absurd for the actual structure of reductio ad absurdum. The real form used in this argument is modus ponens:
If p then q.
p.
Therefore, q. (Weston 40)
The Correct Use of Reductio Ad Absurdum in Media
Reductio ad absurdum is a tool used regularly in film, both in character dialogue and as a tool to move plots forward outside of dialogue. By this I mean that reductio can be used by screenwriters to convince the audience of the storyline. An example of reductio being used correctly in film is in The Princess Bride, when Fezzik, Inigo, Vizzini and Buttercup are traveling by sea to the Cliffs of Insanity when an argument breaks out between Inigo and Vizzini. In this argument, Inigo asks whether they are being followed, to which Vizzini responds that it is inconceivable. The argument in question follows this form:
There is a ship on the horizon that is following us.
They are not following us; it is just a fisherman enjoying a leisurely night sail through eel-infested waters.
It would be absurd to assume that a fisherman would travel through eel-infested waters at night.
Therefore, the ship must be following us.
This follows the logical structure of reductio ad absurdum. Not only is this an example of the correct use of reductio, but it is also an example of an effective use of reductio. Despite the relativity of absurdity, this argument makes it difficult to believe anything other than the original premise that the ship in question is following them!
The comedy Elf has two examples of reductio ad absurdum, both in character dialogue and within the plot. The first instance of the form is a scene in which Buddy the Elf and Papa Elf are doing maintenance work on Santa’s sleigh. In this scene, Papa Elf reveals that the sleigh can’t fly on its own because many people no longer believe in Santa Claus. Buddy responds by using reductio:
Santa Claus is real.
Santa isn’t real, the parents give all the presents and eat the cookies.
This is absurd because the parents would not be able to do it all in one night.
Therefore, Santa Claus must be real! To assume otherwise is absurd.
This is another example where reductio is used correctly. The main question now is whether it is effective or not. The interesting thing about this example is that while it is extremely effective in the world of the movie, in real life the argument is the exact opposite! This is a great example of absurdity being relative to the background of the individuals engaged in the argument.
This last example is a scene from Elf in which reductio is used within the plot of the movie to convince the audience, rather than another character. This is the scene where Buddy learns that he is a human. In this scene, we see a flashback of all the signs that he was different from the other elves. If we were to write this in reductio form, it would look like this:
Buddy the Elf is a human.
UNLESS....Buddy is an elf!
But this would be absurd because he is too big for the elf lifestyle.
Therefore, Buddy is, indeed, a human.
Once again, this is a valid use of reductio ad absurdum although in this instance, the argument can be found within a montage series of flashbacks, rather than dialogue.
The Relativity of Absurdity
As illustrated above, Reductio ad absurdum is a difficult structure to get right. Reductio ad absurdum can be a very powerful deductive form when used correctly, however often it is used incorrectly or ineffectively. It is not surprising that many people fail to use reductio correctly because of how often it is misrepresented. It is difficult to understand what the form is with so many terrible examples of it online, however, reductio is a tricky structure to use even when you understand it! This is because of the relativity of absurdity.
One could argue that the form is most effective when both parties already have similar beliefs, as people with differing viewpoints or backgrounds may have varying opinions on what qualifies as “absurd”. Some people even have a higher tolerance for absurdity than others. Because of the relativity of absurdity, this deductive form is prone to corruption by the fallacy of overlooking alternatives, even when used correctly. The most effective use of reductio is when you prove the opposite to be impossible, rather than just absurd.
Works Cited
The Big Bang Theory TV Show Blooper, slipups.com/items/34389.html#google_vignette.
Accessed 6 May 2024.
Elf. Directed by Jon Favreau, Warner Bros., New Line Cinema, 7 Nov. 2003.
Graham, Nick. “Reductio Ad Absurdum - the Comedy of Dave Chappelle.” Medium,
Medium, 19 Oct. 2019, <medium.com/@nick.g.52/reductio-ad-absurdum-the-
The Princess Bride. Directed by Rob Reiner, 20th Century Studios, Metro-Goldwyn-Mayer,
Lionsgate, Vestron Pictures, 9 Oct. 1987.
Reductio Ad Absurdum and Humor, <www.jesterbear.com/Wicca/AbsurdumHumor.html>
Accessed 6 May 2024.
Weston, Anthony. A Rulebook for Arguments, 5th edition. Indianapolis: Hackett
Publishing Company, Inc., 2017.
Ivy Altman took classes at CT State Tunxis this spring.
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