Non Sequitur Fallacy | Definition & Examples

A non sequitur fallacy is a statement or conclusion that does not follow logically from what preceded it. Non sequiturs can be responses that have nothing to do with the conversation or flawed conclusions “based” on what preceded them.

Non sequiturs may appear in various contexts, including everyday conversations, political speeches, and literary texts. Non sequitur fallacy is also known as irrelevant reason, derailment, and invalid inference.

What is a non sequitur?

A non sequitur is any argument that does not follow from the previous statements. The phrase “non sequitur” means “it does not follow” in Latin. Although the term was originally used in the context of philosophy to denote poor logic, nowadays it is used more broadly for any kind of statement that seems to come out of the blue.

In literature, a non sequitur is often used intentionally as a literary device. Irrelevant or absurd comments are injected for comedic effect in theatrical plays, novels, or stand-up comedy. Non sequiturs may serve as transitions to change the subject or mood, or they can signify that a character is not paying attention.

In logic, non sequiturs are considered a type of logical fallacy. When a conclusion is supported only by weak or irrelevant reasons, the argument is fallacious and is said to be a non sequitur.

What is a non sequitur fallacy?

A non sequitur is a formal logical fallacy because the error lies in the argument’s structure. More specifically, there is a logical gap between the premise or the evidence provided and the conclusion drawn from this. Even if the premises are true, like in the example above, the conclusion does not follow: maybe “that creature” is a bird, but bees have wings too.

All formal fallacies are in fact non sequiturs because they involve conclusions that do not naturally or logically follow from the evidence provided. For this reason, “non sequitur” and “formal fallacy” are sometimes used interchangeably. However, the term “non sequitur” usually refers to those types of formal fallacies that do not have a more specific fallacy name.

How to identify a non sequitur

A non sequitur argument is distinguished by reasoning or evidence that is completely irrelevant to the claim being made. Non sequiturs have the following characteristics:

• They are statements that do not provide any information in relation to the question or statement that came before.
• They are not just random statements. Instead, they are responses to something that preceded them. If you walked up to a stranger and said “polar bears can reach speeds of up to 6 mph in the water,” it would be random (if not a little scary). But if a friend asked you how you are doing and you replied with something about polar bears, that would be a non sequitur.
• They are often absurd or surreal and can be used to add a sense of humor.
• Non sequiturs often contain words like “so” and “therefore,” but the context of the statement can also suggest that this is a conclusion.

Non sequitur examples

Non sequitur fallacies are obvious when they are absurd, but sometimes they can fly under the radar because the logical leap may be harder to spot.

Non sequiturs serve several purposes in literature. Writers often use them to confuse the reader or to indicate absurdity. In Alice’s Adventures in Wonderland by Lewis Carroll, we see an example of a non sequitur in the following conversation.

The remark made by the Hatter does not relate to the original statement made by Alice (it is completely irrelevant).

Samuel Becket’s classic play Waiting for Godot is full of non sequiturs, making it hard to follow the dialogue. This is intentional, because the difficulty of establishing meaningful communication is one of the main themes of the play.

While the two characters are seemingly having a discussion, they do not in fact answer each other’s questions. For the most part, their comments are not logically connected to anything that came before.

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If you want to know more about fallacies, research bias, or AI tools, make sure to check out some of our other articles with explanations and examples.

Frequently asked questions about the non sequitur fallacy

What is an example of non sequitur?

An example of a non sequitur is the following statement:

“Giving up nuclear weapons weakened the United States’ military. Giving up nuclear weapons also weakened China. For this reason, it is wrong to try to outlaw firearms in the United States today.”

Clearly there is a step missing in this line of reasoning and the conclusion does not follow from the premise, resulting in a non sequitur fallacy.

What is the difference between the post hoc fallacy and the non sequitur fallacy?

The difference between the post hoc fallacy and the non sequitur fallacy is that post hoc fallacy infers a causal connection between two events where none exists, whereas the non sequitur fallacy infers a conclusion that lacks a logical connection to the premise.

In other words, a post hoc fallacy occurs when there is a lack of a cause-and-effect relationship, while a non sequitur fallacy occurs when there is a lack of logical connection.