fallàcies

Fallàcies are errors in reasoning that undermine the strength of an argument. They can be classified as formal, which involve a defect in the logical structure, or informal, which arise from the content, language, or assumptions of the argument. A fallacy may be persuasive and compelling, but it does not provide sound justification for the conclusion.

Etymology and history: The term derives from Latin fallacia, deception. In classical philosophy, Aristotle and later logicians studied deceptive or misleading reasoning and developed catalogs of common fallacies. Over time, the concept broadened to include a range of errors encountered in everyday argumentation, rhetoric, and scientific discourse.

Categories and examples: Formal fallacies concern the form of a deductive argument and render the argument invalid. Examples include affirming the consequent and denying the antecedent. Informal fallacies involve relevance, presumption, ambiguity, or questionable evidence. Common informal fallacies include ad hominem, straw man, appeal to authority, false dilemma, post hoc ergo propter hoc, hasty generalization, red herring, and begging the question.

Impact and evaluation: Recognizing fallacies is central to critical thinking, scientific reasoning, and judicial or public discourse. Identifying a fallacy helps assess whether conclusions are adequately supported by evidence. Approaches to avoid fallacies include clarifying terms, examining premises, separating correlation from causation, evaluating sources, and reconstructing arguments in neutral form.

See also: List of fallacies; critical thinking; logical argument. Fallàcies continue to be a core concept in logic, rhetoric, and media literacy, used to diagnose faulty reasoning and to improve argumentative standards.