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What Are Fallacies?

Fallacies (also called sophisms or fallacies in English) are flawed patterns of argumentation that violate the principles of logical thinking. They exhibit structural or substantive flaws that impair the validity or soundness of the argument.

All fallacies are

Characteristics of Fallacies​

  1. Apparent plausibility: Fallacies often seem convincing at first glance.
  1. Logical errors: They contain errors in the structure of the argument or in the application of logical principles.
  1. Psychological effectiveness: Many fallacies are psychologically effective because they appeal to emotions, prejudices or cognitive biases.
  1. Prevalence: Fallacies are widespread in everyday discussions, political debates, advertising and even in scientific contexts.

Why Are Fallacies Problematic?​

Fallacies are problematic for several reasons:

  1. They lead to false conclusions: Flawed patterns of argumentation can lead to inaccurate or unfounded conclusions.
  1. They hinder productive discussions: Fallacies can lead discussions astray and distract from the actual points of contention.
  1. They can be used manipulatively: Fallacies are often deliberately used to deceive or manipulate others.
  1. They make critical thinking more difficult: If we fail to recognise fallacies, we can easily fall into the trap of accepting flawed arguments.

Types of Fallacies​

Fallacies can essentially be divided into two large groups: formal and informal fallacies.
As we have already said, many good arguments are not formally logically valid anyway. And if they are also flawed, they are called informal fallacies.

  1. Formal fallacies: These violate the rules of formal logic and are flawed regardless of the content of the statements.
    We find these formal fallacies above all in arguments that are meant to be formally logically valid, such as in mathematics, logic, set theory or theoretical computer science.
  1. Informal fallacies: These are problematic in terms of content or context and can be further subdivided into:
    • Fallacies of relevance: Arguments that use irrelevant information
    • Fallacies of ambiguity: Arguments based on ambiguities or vagueness
    • Fallacies of presumption: Arguments based on unjustified assumptions

Below we will look at the most important fallacies from each category.