This series tackles basic topics in logic through text & video lessons. Topics are organized below.
General logic stuff
Get a taste of the basics of logic with Socrates' questioning and Aristotle's syllogisms. Explore the difference between form and content, variables and operators, valid vs. true conclusions, and reasoning vs. reasoning well as you think about thinking.
How do words and other signs mean something? How is meaning studied? Get a brief idea of the various approaches to meaning in language.
Core lessons in logic
Use the language of logic to translate ordinary language into precise logical statements and then analyze that logic. Constants versus variables, subjects versus predicates, quantifiers, connectives/operators and sets are all introduced in a way that's easy to apply to everyday language.
Build on your use of logic to understand arguments with multiple statements. Distinguish between the form and content of arguments. Explore concepts of truth & validity, and deductive versus inductive reasoning. Finally, begin to identify informal and formal logical fallacies.
Expand your understanding of truth values in logic through truth tables. Compare binary (true/false) truth values of propositions and operators, including the negation NOT, conjunction AND, disjunction OR, implication/conditional IF...THEN and the biconditional IF AND ONLY IF. The analogy of a lightbulb and lightswitch are used to illustrate each operator.
See how an implication can be flipped around and negated in propositional logic. Use the example 'if it's a bike it has 2 wheels' to explore converses, inverses and contrapositives. Then, abstract that relationship to any two propositions A and B, where A implies B.