Post Hoc Fallacy: Why Coincidence Isn’t Always Cause
Introduction and Definitional Scope The Post Hoc Fallacy, formally known in Latin as post hoc ergo propter hoc—meaning “after this, therefore because of this”—is one of the most pervasive and fundamental logical errors encountered in reasoning, statistics, and experimental design. Fundamentally, this fallacy involves the erroneous inference that because event B occurred immediately following event […]
Formal Logic: Why Your Brain Gets It Wrong
Affirming the Consequent: A Logical Fallacy The Core Definition of Affirming the Consequent Affirming the Consequent (AFC) is a fundamental error in formal logic, classified as a non-sequitur and one of the two main formal fallacies concerning hypothetical syllogisms. At its core, AFC occurs when one assumes that because the consequence of a conditional statement […]
Base-Rate Fallacy: Why Your Brain Ignores the Odds
Conceptual Definition of the Base-Rate Fallacy The Base-Rate Fallacy, which is frequently identified in cognitive science as base-rate neglect, is a pervasive error in human reasoning that occurs when a decision-maker prioritizes specific, individualized information over the general statistical data relevant to a particular phenomenon. This cognitive bias leads individuals to systematically ignore the base […]
Post Hoc Fallacy: Why Correlation Is Not Causation
Introduction and Formal Definition The Latin phrase Post Hoc Ergo Propter Hoc translates literally to “following this, therefore due to this.” This term names a fundamental type of logical fallacy, specifically a fallacy of questionable cause, where the mere temporal sequence of two events is erroneously taken as proof of a causal relationship. It is […]
Formal Fallacies: Unmasking Hidden Logical Errors
Introduction to Formal Fallacies The term Formal Fallacy designates a profound structural defect within deductive arguments, signifying a violation of fundamental principles intrinsic to formal logic. Unlike errors rooted in content, ambiguity, or empirical falsehood, a formal fallacy is exclusively concerned with the argument’s form, rendering the conclusion logically disconnected from the premises, regardless of […]
False Analogy: Why Your Brain Loves Flawed Logic
Definition and Core Concepts The concept of the False Analogy, also frequently termed the Faulty Analogy or Weak Analogy, describes a logical fallacy belonging to the category of weak induction. This fallacy occurs when an argument relies upon a comparison between two objects, situations, or phenomena that are not sufficiently alike in relevant respects to […]
Arbitrary Inference: Why Your Brain Jumps to Conclusions
Defining Arbitrary Inference Arbitrary Inference stands as a fundamental cognitive distortion within the framework of cognitive behavioral therapy (CBT), specifically delineated by psychologist Aaron Beck. It refers precisely to the psychological process wherein an individual arrives at a definitive conclusion despite having either insufficient, absent, or, critically, actively contradictory evidence supporting that claim. This error […]
Logical Fallacies: Why Your Brain Gets Logic Wrong
Introduction and Formal Definition The logical error known as Denying the Antecedent is a formal fallacy committed when one argues that because the antecedent (the “if” clause) of a conditional statement is false, the consequent (the “then” clause) must also be false. This reasoning structure is fundamentally flawed because the truth of a conditional statement […]