Deductive Reasoning

Flashcards covering key concepts of deductive reasoning and categorical syllogisms.

Categorical Syllogism

A logical structure consisting of three categorical terms: major term, minor term, and middle term.

Major Term

The term that appears as the predicate in the conclusion and only once in the major premise.

Minor Term

The term that appears as the subject in the conclusion and only once in the minor premise.

Middle Term

The term that appears once in the major premise, once in the minor premise, and is not present in the conclusion.

Mood

The format used to express the type of syllogism: A = All S are P, E = No S are P, | = Some S are P, O = Some S are not P.

Modus Ponens

A valid argument form that states if 'All S are P' and 'A is S', then 'A is P'.

Modus Tollens

A valid argument form that states if 'If A then B' and 'Not B', then 'Not A'.

Affirming the Consequent

A formal fallacy where one assumes that if 'If A then B' and 'B' is true, then 'A' must also be true.

Distribution

The status of a term in a syllogism indicating whether it references all members of the category.

Hypothetical Syllogism

A syllogism formed by putting together conditional statements.

Disjunctive Syllogism

A valid reasoning form that concludes 'A or B' followed by negating one of the options and affirming the other.

Denying the Antecedent

A fallacy that occurs when one infers 'Not B' from 'If A then B' and 'Not A'.

Rules for Syllogisms

Six specific guidelines ensuring valid syllogistic reasoning, including the correct distribution of terms and premises.