The Negative Conclusion from Affirmative Premises is a type of logical error that occurs when someone mistakenly draws a negative conclusion (e.g., “not all x are y”) from premises that only provide positive information (e.g., “all x are y” or “some x are y”). Example: “All employees who work on weekends receive overtime pay.” (Premise […]

The Illicit Minor is a type of logical error that occurs when someone mistakenly uses a specific case or instance as the minor premise in an argument, but then draws a conclusion that applies to all cases. Example: “All mammals are warm-blooded.” (Major premise)“The lion is a mammal and lives in the savannah.” (Minor premise)“Therefore, […]

The Illicit Major is a type of logical error that occurs when someone mistakenly uses a universal statement (all) as the major premise in an argument, but then draws a conclusion that only applies to some or one specific case. Example: “All humans are mortal.” (Major premise)“Socrates was human.” (Minor premise)“Therefore, Socrates is the only […]

The Fallacy of Exclusive Premises is a type of logical error that occurs when someone mistakenly concludes a statement from two or more premises that are mutually exclusive. Example: “Either John is a doctor or he is an engineer.” (Exclusive premise 1)“John is not a doctor.” (Exclusive premise 2)“Therefore, John must be an engineer who […]

The Affirmative Conclusion from a Negative Premise (also known as Illicit Negative) is a type of logical error that occurs when someone mistakenly concludes an affirmative statement from one or more negative premises. Example: “Nobody knows the answer to this question.” (Negative premise)“Therefore, John knows the answer.” (Affirmative conclusion) In this example, the argument starts […]

The Existential Fallacy is a type of logical error that occurs when someone mistakenly assumes that because something exists or has existed, it must have always existed or will continue to exist. Example: “Because some people have always been poor, poverty must be an inherent and eternal aspect of human society.” (Existential Fallacy) In this […]

The Denying the Antecedent is a type of logical error that occurs when someone mistakenly assumes that because the antecedent (the “if” part) of a conditional statement is false, the consequent (the “then” part) must also be false. Example: “If it rains, the streets will be wet.” (Conditional statement)“It didn’t rain.”“Therefore, the streets are not […]

The Affirming the Consequent is a type of logical error that occurs when someone mistakenly assumes that because a conditional statement (if-then) has a true consequent (the “then” part), the antecedent (the “if” part) must also be true. Example: “If it rains, the streets will be wet.” (Conditional statement)“The streets are indeed wet.”“Therefore, it must […]

Logic refers to the systematic study of reasoning and argumentation, encompassing various methods for evaluating arguments, identifying patterns of valid reasoning, and distinguishing between sound and unsound conclusions. It involves the use of logical operators, rules of inference, and formal systems to analyze and evaluate statements, propositions, and arguments. Key Aspects of Logic: Branches of […]

The Affirming the Disjunct is a type of logical error that occurs when someone mistakenly assumes that one part of a disjunction (an “or” statement) being true means that the entire disjunction must be true. This fallacy gets its name from the fact that affirming one disjunct is not sufficient to prove the truth of […]