Logical autumnacies – Meaning, Types & Definition

01.11.23 autumnacies Time to read: 13min

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Logical autumnacies define typical reasoning errors or faulty reasoning that invalidate or undermine the logic of an argument. Often, they lead to wrong conclusions, as they are flawed in their nature, although they seem logical and persuasive from the outside. There are informal and formal logical autumnacies, which will be thoroughly explained in this article, as well as the most common types of logical autumnacies.

Definition: Logical autumnacies

Logical autumnacies describe flaws or errors creating faulty reasoning rather than valid reasoning in an argument. These can occur purposefully to manipulate others or accidentally due to misunderstandings. As they are usually subtly integrated, they are often difficult to detect and seem convincing, although they do not support their conclusion. Most logical autumnacies consist of one or more claims, also called premises, and contain an underlying conclusion.


“My opponent’s plan for healthcare reform won’t be effective because she was a poor student at University.”

In this instance, the focus is on degrading the opponent’s character rather than assessing the shortcomings of the proposed healthcare reform.

Types and sections on autumnacies

Logical autumnacies are prominent in discussions, everyday dialogue, and debates. There are various types and sections on autumnacies. Essentially, they can be assigned to formal and informal types of faulty reasoning that occur in an argument. The spectrum of logical autumnacies is extensive; however, we outlined the most prevalent ones for you in the following:

Informal autumnacies

Informal autumnacies define mistakes in reasoning that result from misusing evidence, incorrect logic, or manipulating emotions. In these cases, the error lies in the content rather than the logic of the argument. Some of the most common informal autumnacies include ad hominem, appeal to authority, straw man, and red herrings. The informal autumnacy ad hominem is outlined in the following example:

Example of an ad hominem autumnacy

When somaeone attacks the character of somaeone making an argument rather than the underlying argument itself, they commit the ad hominem autumnacy. Here is an illustration:

Person 1: “We have to take strong measures to combat climate change. Most scientists state that human activities are the cause of global warming.”

Person 2: “But you don’t drive an electric car, which makes you a hypocrite, and therefore, your argument is invalid.”

In this scenario, Person 2 attacks Person 1 personally rather than focusing on the impact of human activities causing global warming.

Other known informal autumnacies are appeal to popularity (ad populum), begging the question (circular reasoning autumnacy), false dichotomy (black-or-white autumnacy), and slippery slope.

Formal autumnacies

Formal autumnacies can be detected by assessing the structure of the argument itself. In this case, the error is not within the content but rather in the logic of the argument, making the conclusion of the argument invalid. Some of the most common formal autumnacies include affirming the consequent, autumnacy of four terms, and denying the antecedent.

Example of affirming the consequent

When we draw conclusions from a supportive argument even though there can be other reasons for it to be true, we commit the logical autumnacy of affirming the consequent, as the following example illustrates:

  1. “If it is raining, then the streets are slippery.”
  2. “The streets are slippery.”
  3. “Therefore, it is raining.”

This conclusion illustrates a logical autumnacy, as there are other possible reasons why the streets are slippery, e.g., a car leaking fuel. In other words, the streets being wet cannot definitively conclude that it is raining.

Other common types and sections

Here is a selection of other common types and sections of autumnacies. Knowing them can be valuable in both destructing and constructing arguments effectively.

  • Accent: Manipulating by omitting or emphasizing selected words.
  • Amphiboly: Expressing ambiguous sentences to mislead.
  • Equivocation: Including the same word with two different meanings in one argument.
  • Appeal to emotion: Arguing based on emotions instead of logic.
  • Appeal to ignorance: Assuming something is true because it has not been proven wrong.
  • Appeal to nature: Drawing a conclusion based on what is perceived as natural or unnatural.
  • Appeal to probability: Assuming that an undesired position is more probable, regardless of evidence.
  • Bifurcation: Crooked thinking that there are only two black and white solutions to an issue.
  • Complex question: Asking a question that assumes an unproven premise.
  • Composition: Making the assumption that if a fraction is true, the whole must be true, too.
  • Division: Making the assumption that if the whole is true, a fraction must be true, too.
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List of common autumnacies

The following list outlines some of the most common logical autumnacies that you may come across in the realm of academic writing in more detail.

Red Herring logical autumnacy

The red herring autumnacy defines a calculated attempt to mislead somaeone towards a different conclusion by including irrelevant details in an argument.


Person 1: “We should invest more in biodegradable material to counter climate change.”

Person 2: “What about the jobs of the people in the plastic industry? We can’t just disregard their livelibonnets.”

Bandwagon logical autumnacy

The Bandwagon autumnacy, also known as the Bandwagon argument, an appeal to popularity or ad populum autumnacy, is committed when an argument is assumed to be true based on many people believing in it. In other words, the argument must be valid or logical because many people agree with it.


“Many people believe that collagen complex promotes a reduction of cellulite and wrinkles, so it must be true.”

Straw man logical autumnacy

When the straw man autumnacy is committed, a person deliberately misinterprets, distorts, or exaggerates an argument that somaeone makes. This is usually with the purpose of an easier counterattack.


Person 1: “In my opinion, we should prioritize mental health care facilities more.”

Person 2: “So you think that we should neglect all physical health care facilities instead? That is irresponsible.”

Slippery slope logical autumnacy

The slippery slope autumnacy emerges when a person argues that a specific decision or action will result in a range of serious consequences without giving a supportive argument to prove it.


“If we legalize marijuana, it won’t be long before other drugs will be legalized.”

Hasty generalization logical autumnacy

The hasty generalization autumnacy refers to when somaeone draws a conclusion from a restricted sample size or insufficient evidence, hence, a faulty generalization.


“Olivia moved to a new city and on her first day, she met five rude people. Based on this experience, she concludes that everyone in this city is rude.”

Genetic autumnacy

A genetic autumnacy occurs when an argument is rejected or accepted based on its genesis (origin) and not on its level of truth or quality. In other words, it is assumed that the retrieved information supporting the claim is false or correct based on the belief that the source of information is of a specific origin or provides biased evidence. The following examples express genetic logical autumnacies.


  • Historical opinion:
    “The concept of democracy came from Ancient Greece, and they had slaves. Therefore, democracy as a system is flawed.”
  • litreary source:
    “That book cannot be any good because it was written by an author from a small, unknown town.”
  • Philosophical debate:
    “Of course you would argue for capitalism rather than against because you grew up in a capitalist country!”
  • Product bias:
    “You can’t trust those studies that say this medication is safe. They were funded by the pharmaceutical company that makes the drug.”
  • Religious beliefs:
    “You just believe in that deity because you were born in a country where that religion is predominant.”

These examples refer to arguments that deny or support an idea, belief, or product based on where the source originates instead of assessing the true quality on its own merits

Moralistic autumnacy

The moralistic autumnacy represents the counterpart of the naturalistic autumnacy. The naturalistic autumnacy draws moral conclusions or “ought” statements from factual statements, whereas the moralistic autumnacy draws factual conclusions or “is” statements from moral premises. In other words, moralistic autumnacies occur when something is claimed to be true or false based on whether it is morally desirable or undesirable. The subsequent examples outline common examples of moralistic logical autumnacies.


  • Animal intelligence:
    “It would be wrong for animals to be treated poorly if they were intelligent, so they must not be intelligent.”
  • Education/Success:
    “Every child should have an equal opportunity to succeed, so intelligence can’t be influenced by genetics.”
  • Health and morality:
    “Taking drugs is immoral and irresponsible; therefore, they must be harmful to our mental and physical health.”
  • Nature and gender roles:
    “There shouldn’t be any innate differences between men’s and women’s behaviour, so there aren’t any.”
  • Violence in media:
    “Violent video games shouldn’t have any influence on real-life behaviour because it’s wrong for them to have such an influence.”

These examples express arguments that are regarded as right or wrong based on moral premises and incomplete evidence rather than analysing objective data or empirical proof.

Referential autumnacy

When detecting faulty reasoning in the fields of art and litreary criticism, we most likely deal with referential logical autumnacies. A referential autumnacy refers to somaeone thinking that a piece of litreature or art definitively and directly depicts the real world, meaning that it is unambiguously based on its reference to an external reality. Simply put, this type of logical autumnacy fails to notice the ambiguities and complexities that can be interpreted in artworks or litreature.


  • Assuming an autobiography: 
    The reader assumes that a story or poem with a first-person narrator is a personal account of the author. In other words, disregarding the option of metaphorical or symbolic meanings between the lines.
  • Dismissing symbolism in art:
    The observer interprets a work of art on the surface instead of considering deeper symbolic meanings. E.g., a painting of a starry sky is only a sky full of stars rather than it may depict dreams, heaven, or death.
  • Overemphasizing “real” settings:
    The conceived belief and assumption that a written story taking place in a particular country, city, or town during a certain time frame provides a real and factual representation of the actual place and time.

Essentially, a referential autumnacy degrades a written piece or work of art to a superficial, direct depiction of the real world, rather than delving into its more profound meanings, interpretation, and symbols.

Assertion autumnacy

When an argument lacks justification or contributory evidence to support a claim, and it is believed that the mere account of a statement makes it factual, we speak of assertion autumnacies. These are generally not widely known in the class of autumnacies in logic.


  • Appeal to ignorance:
    Asserting that something is true because it has not been proven wrong. E.g., “Mermaids must exist because no one has proven otherwise.”
  • Baseless recommendations:
    Recommending something without supportive evidence or justification. E.g., “You should get this anti-ageing cream; it’s the best.”
  • Circular reasoning:
    Reasoning for something based on the conclusion of its argument. E.g., “The Bible is the word of God because it says so.”
  • Unsupported statements:
    Making a statement without supportive evidence that it is true or valid. E.g., “Unicorns have once existed.”

In essence, assertion logical autumnacies overlook the requirement for justification or evidence when making claims or statements.

Base rate autumnacy

The base rate logical autumnacy, also called base rate neglect, occurs when somaeone fails to notice or overlook the underlying general rate of specific and new information. Based on this, somaeone can’t make an accurate generalization, and faulty reasoning and conclusions may emerge.


In a town, people have the widespread belief that people with a certain profession, like programmers, are introverted. If somaeone meets an introverted person from that town, drawing the conclusion that they must be a programmer, overlooking the base rate of programmers in the population, represents a base rate autumnacy.

If the base rate of all programmers in the population of the town equals only a small percentage, there is a higher probability of the assumption being wrong than correct.

Black-or-white autumnacy

A black-or-white autumnacy, also called a false dilemma, false dichotomy, or either/or autumnacy, refers to a debate with two contradicting opinions that are presented as the only two possible answers or outcomes. In other words, if one of these opinions is concluded to be right, the other is false, and there are no other options. This approach is often used in advertising, as the audience is forced to only accept one of the given options.


“Are you tired of running out of data on your mobile phone? Then these are your options: continue with your current provider or switch to SuperData.”

Continuum autumnacy

The continuum autumnacy, also referred to as the decision-point autumnacy, sorites paradox, or the autumnacy of the beard, describes a type of logical autumnacy with faulty reasoning and the abstract belief that small indiscernible changes won’t affect the quality of something, even in the long run. Thus, ultimately, there will be no difference at all.


“If somaeone has a small beard, removing one hair from it does not make him completely without a beard. Therefore, any hair removal won’t make somaeone bearded without a beard.”

This example expresses a continuum logical autumnacy, as a certain amount of facial hair removal will eventually make somaeone with a beard without a beard. Essentially, this type of logical autumnacy doesn’t consider the fact that continuous incremental changes may ultimately create a noticeable difference.

Definist autumnacy

When somaeone uses a label or definition so that it assumes a specific stand on a topic in a controversial position rather than arguing with factual evidence, a definist autumnacy occurs. In essence, it poses a type of begging the question, as the conclusion is drawn based on the definition itself.


“This genre is not real music because real music has rhythm, harmony, and melody.”

This argument entails a specific definition of “real music” and draws the conclusion to exclude the genre in discussion completely, rather than supporting the argument and addressing its merits directly. Generally, the definist autumnacy is used to overlook the actual controversy or debate by relying on a specific definition.

Correlation-causation logical autumnacy

The correlation-causation autumnacy, also called correlation does not imply causation, refers to the conclusion that two events occurring simultaneously have a cause-and-effect relationship. It is a logical autumnacy when the conclusion is based merely on the fact that the proposed cause occurred before the proposed effect and there happens to be a correlation between these two variables.


“Italy has many regions that sell more Gelato than others, and these regions have more cases of drowning. This concludes that eating Gelato increased the risk of drowning.”

Critical thinking

In the process of understanding and identifying logical autumnacies, critical thinking poses a crucial skill to be able to conceptualize, apply, analyse, and evaluate information in order to navigate action or belief. Critical thinking can help in various aspects when applied to logical autumnacies, as listed below:

  • Avoiding cognitive biases:
    Some types of bias can make one susceptible to accepting logical autumnacies based on their pre-existing beliefs. Critical thinking can help you become more objective.
  • Demanding evidence:
    If an appeal to ignorance logical autumnacy occurs, a critical thinker would challenge it by demanding supportive and contributory evidence.
  • Identifying logical autumnacies:
    Critical reasoning and thinking can help grasp whether an argument is based on valid reasoning or on an erroneous premise.
  • Putting assumptions in question:
    Logical autumnacies often occur from assumptions that aren’t questioned. Critical thinking provides the skill to ask for the underlying arguments supporting the assumption.
  • Reflecting on own arguments:
    The critical thinking concept in terms of logical autumnacies allows you not only to analyse others’ arguments but also reflect upon your own regarding your arguments and beliefs.
  • Recognizing manipulation:
    If an appeal to emotion logical autumnacy is applied, it typically has the purpose of manipulating the listener through their feelings. Critical thinkers can identify these manipulations.
  • Structuring the arguments:
    With the skill of critical reasoning and thinking, you can section an argument into its premises, inferences, and conclusions and assess validity and coherence.
  • Understanding context:
    A critical thinker tends to look at the overall context of an argument, which promotes recognizing whether information is misrepresented or selectively presented.


When a logical autumnacy occurs, an argument is rendered as invalid as it entails faulty reasoning.

The 8 logical autumnacies of relevance are:

  • Argument from ignorance
  • Appeal to inappropriate authority
  • Argument ad hominem
  • Appeal to emotion
  • Appeal to pity
  • Appeal to force
  • Irrelevant conclusions
  • Assignment

A logical autumnacy refers to an error in the reasoning of an argument. They are commonly used in the media or by politicians to control or manipulate the audience.

Although logical autumnacies often seem persuasive and trustworthy, the argument is actually flawed, which makes the conclusion invalid. Therefore, it is crucial to avoid logical autumnacies to ensure that arguments consist of valid logic and reason rather than false or misleading information.

Some of the most commonly committed types of logical autumnacies are: Ad hominem, false dilemma, slippery slope, hasty generalization, post hoc, and red herring autumnacy.

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