Overview

Logic is the key to philosophy, mathematics, and science. Learn logic from an award-winning professor of philosophy.

Flawed, misleading, and false arguments are everywhere. From advertisers to politicians, your beliefs are constantly under attack. Logic is intellectual self-defense against flawed reasoning and a method to validate your own views. Beyond practical benefits, informal logic leads to formal logic—philosophy’s equivalent to calculus.

Professor Steven Gimbel of Gettysburg College guides you through 24 engaging lectures, covering everyday fallacies to advanced formal logic. Packed with real-world examples, this course suits beginners and experts alike.

Why Study Logic?

Cognitive biases make us prone to false beliefs. Logic corrects these errors, sharpening reasoning skills for philosophy, science, and daily life.

Video Lectures

• Why Study Logic? (26 min)
  • Explore cognitive biases and the role of logic in rational thinking.

2. Introduction to Logical Concepts (30 min)
   • Identify deductive vs. inductive arguments using indicator words.

• Informal Logic and Fallacies (30 min)
  • Circular reasoning, begging the question, equivocation, and false distinctions.

4. Fallacies of Faulty Authority (33 min)
   • Appeals to authority, tradition, novelty, and analogies.

5. Fallacies of Cause and Effect (28 min)
   • Post hoc, common cause neglect, oversimplification, and slippery slopes.

• Fallacies of Irrelevance (28 min)
  • Ad hominem, straw man, and red herring tactics.

7. Inductive Reasoning (31 min)
   • Pitfalls: selective evidence, small samples, unrepresentative data.

• Induction in Polls and Science (32 min)
  • How polling and science rely on reliable inductive reasoning.

9. Introduction to Formal Logic (29 min)
   • Aristotle’s deductive methods for absolute validity.

• Truth-Functional Logic (31 min)
  • Frege’s connectives (“not,” “and,” “or”) and computer logic.

• Truth Tables (28 min)
  • Map argument premises to test validity.

12. Truth Tables and Validity (26 min)
    • Test modus ponens and complex arguments.

13. Natural Deduction (34 min)
    • Game-like proofs mirroring human reasoning.

14. Logical Proofs with Equivalences (33 min)
    • Double negation and other truth-functional equivalences.

• Conditional and Indirect Proofs (35 min)
  • Using assumptions to validate arguments.

16. First-Order Predicate Logic (29 min)
    • Analyzing internal sentence structure.

• Validity in First-Order Logic (35 min)
  • Natural deduction rules for predicate arguments.

• Demonstrating Invalidity (31 min)
  • Counter-examples and expansion methods.

19. Relational Logic (31 min)
    • Proving relational statements (e.g., “taller than”).

20. Logical Identity (33 min)
    • Validating equivalence relations.

21. Logic and Mathematics (34 min)
    • Euclid’s legacy and non-Euclidean geometries.

• Proof and Paradox (33 min)
  • Gödel’s incompleteness theorems.

• Modal Logic (32 min)
  • Possibility, necessity, and ethical obligations.

• Three-Valued and Fuzzy Logic (29 min)
  • Beyond true/false: multi-valued reasoning.