* Affirming a disjunct – concluded that one disjunct of a logical disjunction must be false because the other disjunct is true; A or B; A; therefore not B. * Affirming the consequent – the antecedent in an indicative conditional is claimed to be true because the consequent is true; if A, then B; B, therefore A. * Denying the antecedent – the consequent in an indicative conditional is claimed to be false because the antecedent is false; if A, then B; not A, therefore not B. A quantification fallacy is an error in logic where the quantifiers of the premises are in contradiction to the quantifier of the conclusion. Types of Quantification fallacies: * Existential fallacy – an argument has a universal premise and a particular conclusion. Syllogistic fallacies – logical fallacies that occur in syllogisms. * Affirmative conclusion from a negative premise (illicit negative) – when a categorical syllogism has a positive conclusion, but at least one negative premise. * Fallacy of exclusive premises – a categorical syllogism that is invalid because both of its premises are negative. * Fallacy of four terms (quaternio terminorum) – a categorical syllogism that has four terms. * Illicit major – a categorical syllogism that is invalid because its major term is not distributed in the major premise but distributed in the conclusion. * Illicit minor – a categorical syllogism that is invalid because its minor term is not distributed in the minor premise but distributed in the conclusion. * Negative conclusion from affirmative premises (illicit affirmative) – when a categorical syllogism has a negative conclusion but affirmative premises. * Fallacy of the undistributed middle – the middle term in a categorical syllogism is not distributed.[11] Informal fallacies – arguments that are fallacious for reasons other than structural (formal) flaws and which usually require examination of the argument's content. * Argument from ignorance (appeal to ignorance, argumentum ad ignorantiam) – assuming that a claim is true (or false) because it has not been proven false (true) or cannot be proven false (true). * Argument from repetition (argumentum ad nauseam) – signifies that it has been discussed extensively until nobody cares to discuss it anymore. * Argument from silence (argumentum e silentio) – where the conclusion is based on the absence of evidence, rather than the existence of evidence. * Argumentum verbosium – See Proof by...

* Affirming a disjunct – concluded that one disjunct of a logical disjunction must be false because the other disjunct is true; A or B; A; therefore not B. * Affirming the consequent – the antecedent in an indicative conditional is claimed to be true because the consequent is true; if A, then B; B, therefore A. * Denying the antecedent – the consequent in an indicative conditional is claimed to be false because the antecedent is false; if A, then B; not A, therefore not B. A quantification fallacy is an error in logic where the quantifiers of the premises are in contradiction to the quantifier of the conclusion. Types of Quantification fallacies: * Existential fallacy – an argument has a universal premise and a particular conclusion. Syllogistic fallacies – logical fallacies that occur in syllogisms. * Affirmative conclusion from a negative premise (illicit negative) – when a categorical syllogism has a positive conclusion, but at least one negative premise. * Fallacy of exclusive premises – a categorical syllogism that is invalid because both of its premises are negative. * Fallacy of four terms (quaternio terminorum) – a categorical syllogism that has four terms. * Illicit major – a categorical syllogism that is invalid because its major term is not distributed in the major premise but distributed in the conclusion. * Illicit minor – a categorical syllogism that is invalid because its minor term is not distributed in the minor premise but distributed in the conclusion. * Negative conclusion from affirmative premises (illicit affirmative) – when a categorical syllogism has a negative conclusion but affirmative premises. * Fallacy of the undistributed middle – the middle term in a categorical syllogism is not distributed.[11] Informal fallacies – arguments that are fallacious for reasons other than structural (formal) flaws and which usually require examination of the argument's content. * Argument from ignorance (appeal to ignorance, argumentum ad ignorantiam) – assuming that a claim is true (or false) because it has not been proven false (true) or cannot be proven false (true). * Argument from repetition (argumentum ad nauseam) – signifies that it has been discussed extensively until nobody cares to discuss it anymore. * Argument from silence (argumentum e silentio) – where the conclusion is based on the absence of evidence, rather than the existence of evidence. * Argumentum verbosium – See Proof by...