• Unit 3: Basic Sentential Logic

    This unit introduces a topic that many students find intimidating: formal logic. Although it sounds difficult and complicated, formal (or symbolic) logic is actually a fairly straightforward way of revealing the structure of reasoning. By translating arguments into symbols, you can more readily see what is right and wrong with them and learn how to formulate better arguments. Advanced courses in formal logic focus on using rules of inference to construct elaborate proofs. Using these techniques, you can solve many complicated problems simply by manipulating symbols on the page. In this course, however, you will only be looking at the most basic properties of a system of logic. In this unit, you will learn how to turn phrases in ordinary language into well-formed formulas, draw truth tables for formulas, and evaluate arguments using those truth tables.

    Completing this unit should take you approximately 13 hours.

    • 3.1: The Basics of Logic

      • 3.1.1: Logical Statements, Connectives, and Relations

      • 3.1.2: Logic Puzzles

    • 3.2: A Little Bit of Formal Logic

        • 3.2.1: How to Write Sentences in Sentential Logic

        • 3.2.2: Connectives and Truth Tables

        • 3.2.3: How to Draw Truth Tables for More Complicated Statements

        • 3.2.4: Properties of Individual Well-Formed Formulas and Relations Between Them

        • 3.2.5: Understanding Truth Tables

        • 3.2.6: How to Translate Ordinary Statements into Symbolic Formulae

        • 3.2.7: Formalization Practice

        • 3.2.8: Two Methods for Determining the Validity of an Argument

        • 3.2.9: Why Sentential Logic Is Not Enough