Logical Arguments and Fallacies

These flashcards cover key concepts, definitions, and types of arguments and fallacies in logic.

Deductive Argument

An argument where the conclusion necessarily follows from the premises.

Valid Deductive Argument

A deductive argument in which, if the premises are true, the conclusion must also be true.

Invalid Deductive Argument

A deductive argument where the conclusion does not necessarily follow from the premises.

Sound Argument

A valid deductive argument that has true premises.

Unsound Argument

A valid deductive argument where not all premises are true.

Slippery Slope

Arguing against a proposed action by claiming it will lead to a series of bad consequences.

Composition Fallacy

Inferring that a whole has a property merely because its parts have that property.

Division Fallacy

Inferring that a part has a property merely because the whole has that property.

Begging the Question

A circular argument in which the proposition is assumed in one of the premises.

Equivocation Fallacy

Using a word with two different meanings in the premises and/or conclusion.

Appeal to Ignorance

Using the absence of proof as evidence for the truth of the opposing proposition.

Diversion Fallacy

Supporting one proposition by diverting attention to another issue.

Ad Hominem

Using negative traits of a speaker as evidence that their statement is false.

Appeal to Authority

Citing an authority's statement as evidence for the truth of a proposition without proper credibility.

False Dichotomy

Excluding relevant possibilities without justification.

Post Hoc Fallacy

Assuming that because one event preceded another, it caused the second event.

Hasty Generalization

Inferring a general proposition from an inadequate sample of particular cases.

Accident Fallacy

Applying a generalization to a special case that is an exception.

Necessary Condition

A requirement that must be met for something else to be true.

Sufficient Condition

A condition that guarantees the outcome is true on its own.

Subjectivism

Concluding that a proposition is true because one wants or believes it to be true.

Appeal to Majority

Using the belief of a large number of people as evidence that a proposition is true.

Appeal to Emotion

Trying to persuade someone to accept a proposition based on emotional responses.

Appeal to Force

Trying to get someone to accept a proposition based on a threat.

Inductive Argument

An argument with premises that suggest the conclusion is likely true.

Inductive vs Deductive Argument

Inductive arguments are likely true; deductive arguments guarantee the conclusion.

Strong Inductive Argument

An argument where the conclusion is likely to be true given the premises.

Weak Inductive Argument

An argument where the conclusion is not probable even if the premises are true.

Cogent Inductive Argument

An inductive argument that has good reasoning and true premises.

Uncogent Argument

An inductive argument where one or more premises are false.