Formal Logic & Argumentation

Quantifiers — All, Some, None

Quantifiers ("all," "some," "none") let logic handle generalizations. Confusing them is one of the most common errors.

Direct Proofs

Discover Direct Proofs as a core part of Formal Logic & Argumentation. This lesson explains what it means, walks through a real example, introduces key terms, and includes three hands-on activities to help you understand and apply the idea.

Aristotle's Syllogisms

Discover Aristotle's Syllogisms as a core part of Formal Logic & Argumentation. This lesson explains what it means, walks through a real example, introduces key terms, and includes three hands-on activities to help you understand and apply the idea.

Modus Ponens

Discover Modus Ponens as a core part of Formal Logic & Argumentation. This lesson explains what it means, walks through a real example, introduces key terms, and includes three hands-on activities to help you understand and apply the idea.

Proof by Contradiction

Discover Proof by Contradiction as a core part of Formal Logic & Argumentation. This lesson explains what it means, walks through a real example, introduces key terms, and includes three hands-on activities to help you understand and apply the idea.

Truth Tables

Discover Truth Tables as a core part of Formal Logic & Argumentation. This lesson explains what it means, walks through a real example, introduces key terms, and includes three hands-on activities to help you understand and apply the idea.