Formal Fallacies

Question 1

What is a formal fallacy?

Answer 1

An error in the argument’s logical structure

Question 2

What are all formal fallacies types of?

Answer 2

Non sequitur

Question 3

What is the fallacy of Appeal to Probability?

Answer 3

A statement that takes something for granted because there is a possibility of it being the case

Question 4

What is the fallacy of Argument from Fallacy (aka the fallacy fallacy)

Answer 4

The assumption that, if a particular premise for a conclusion is false, the conclusion itself must be false

Question 5

What is a Base Rate Fallacy?

Answer 5

Making a probability judgement based on conditional, individuating probabilities, without accounting for the effect of prior ‘Base Rate’ probabilities

Question 6

What is a Conjunction Fallacy?

Answer 6

The assumption that specific conditions are more probably than a single general one

Question 7

What is a Non-sequitur Fallacy?

Answer 7

Where the conclusion does not logically follow the premise

Question 8

What is the Masked-man Fallacy?

Answer 8

Sometimes called the ‘Illicit Substitution of Identicals’, or the ‘Epistemic Fallacy’

Wrongly assuming that if two or more names or description refer to the same thing, they can be freely substituted with one another, This mistake usually hinges on epistemic flaws in knowing something to be true

Question 9

What is a propositional fallacy?

Answer 9

An error of one or many compound propositions in which the truth values of a statement do not satisfy the relevant logical connectives

Question 10

What is the fallacy of affirming a disjunct?

Answer 10

Concluding that one disjunct of a logical disjunction (an ‘or’ statement) must be false because the other is true i.e. A or B; A, therefore not B

Question 11

What is the fallacy of affirming the consequent?

Answer 11

The antecedant in an indicative conditional (an ‘if… then’ statement) is claimed to be true because the consequent is true i.e. if A, then B; B, therefore A

Question 12

What is the fallacy of denying the antecedent?

Answer 12

The consequent in an indicative conditional (an ‘if… then’ statement) is claimed to be false because the antecedent is false i.e. if A, then B; not A, therefore not B

Question 13

What is a quantification fallacy?

Answer 13

A logical error where the quantifiers of the premises are in contradiction to the quantifier of the conclusion

Question 14

What is an existential fallacy?

Answer 14

An argument that has a universal premise and a particular conclusion which does not logically follow i.e.
1 - All trespassers will be prosecuted
2 - Some of those prosecuted are trespassers

Question 15

What is a formal syllogistic fallacy?

Answer 15

Logical fallacies that occur in syllogisms

Question 16

What is a syllogism?

Answer 16

A kind of logical argument that applies deductive reasoning to arrive at a conclusion based on two propositions that are asserted or assumed to be true.

Question 17

What is the fallacy of Affirmative Conclusion from a Negative Premise (Illicit Negative)?

Answer 17

A categorical syllogism has a positive conclusion, but at least one negative premise i.e no fish are dogs, and no dogs can fly, therefore all fish can fly

Question 18

What is the Fallacy of Exclusive Premises

Answer 18

A categorical syllogism that is invalid because both its premises are negative - two negative premises cannot give a logical foundation for a conclusion as they will invariably be independent statements which are no directly related

Question 19

What is the Fallacy of Four Terms (Quaternio Terminorum)?

Answer 19

A categorical syllogism that has four terms - two premises are not enough to connect four different terms since, in order to establish connection, there must be one term common to both premises i.e. All fish have fins; All goldfish are fish; All humans have fins

Question 20

What is the Fallacy of Illicit Major?

Answer 20

A categorical syllogism that is invalid because its major term is undistributed in the major premise but distributed in the conclusion i.e. 1. All dogs are mammals, 2. No cats are dogs, 3. Therefore, no cats are mammals

Question 21

What is the Fallacy of Illicit Minor?

Answer 21

A categorical syllogism that is invalid because its minor term is undistributed in the minor premise but distributed in the conclusion i.e. 1. All A are B, 2. All A are C, 3. Therefore, all C are B

Question 22

What is the Fallacy of Negative Conclusion from Affirmative Premises (Illicit Affirmative)?

Answer 22

A categorical syllogism that has a negative conclusion but affirmative premises - the inability of affirmative premises to reach a negative conclusion is usually cited as one of the basic rules of constructing a valid categorical argument i.e. All colonels are officers; All officers are soldiers: Therefore, no colonels are soldiers

Question 23

What is the Fallacy of the Undistributed Middle?

Answer 23

The middle term in a categorical syllogism is not distributed i.e. 1. All Z is B, 2. All Y is B, 3. Therefore, all Y is Z (B is not distributed and so is invalid)