Introduction to Logic
by Dr. Leonard Peikoff
- 10 lectures, 27 hours
- Recorded in 1974
This course by Dr. Leonard Peikoff provides a comprehensive introduction and overview of the study of logic. Through exercises provided to the reader and discussion of answers, the course covers definitions, syllogisms, fallacies, and the rules of generalization. It is equivalent to a university level course in logic.
Download the entire course (1.07 GB) to listen in the audio player of your choice—or listen online starting with Lecture One below. If listening to the course from this website, be sure to make a note of the current lecture and timestamp before leaving so that you can easily resume where you left off.
Study Guide
This course includes a study guide, featuring questions and other material designed to help you digest the course content. This material accompanies the individual lectures and is also available below as a PDF.
Lecture Guide
Summaries of the lecture content are provided below for your reference and convenience.
| Lecture 1 | This lecture provides an overview of man’s need for logic and the fundamental rules that guide it. Dr. Peikoff provides a definition of logic, discusses its origins in the thought of Aristotle, and reviews the basic axioms of logic. |
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| Lecture 2 | Dr. Peikoff introduces and explains the role of fallacies in logical analysis. He provides numerous examples and concretizations of the most common fallacies as well as a discussion of wider issues relating to them. |
| Lecture 3 | The study of fallacies continues in this lecture. Dr. Peikoff elaborates on the formal fallacies as well as introducing unique Objectivist perspectives and fallacies. |
| Lecture 4 | This lecture begins the discussion of deductive reasoning and the formal analysis of logical reasoning. Dr. Peikoff explains the difference between the validity and truth of an argument and why it matters to logic. He reviews the standard forms of deductive reasoning. |
| Lecture 5 | This lecture begins the discussion and analysis of the syllogism as a logical form. Dr. Peikoff systematically works through the concepts of equivalence and mediation, and explains the parts of a categorical argument. |
| Lecture 6 | This lecture continues the analysis of syllogistic reasoning. Dr. Peikoff works through immediate inferences, contradictions, contraries, alternatives, and implications. |
| Lecture 7 | This lecture examines the nature of logical definition. By working through the ideas of fundamentality, the genus and differentia, and definitional structure, Dr. Peikoff demonstrates the rules of logical definition. |
| Lecture 8 | This lecture is a review of student exercises distributed earlier in the course. |
| Lecture 9 | Dr. Peikoff reviews the field of logical induction. He discusses the nature of generalizations, why they are important, and how generalizations play a role in validation. He contrasts different views of and justifications for induction throughout history. |
| Lecture 10 | This lecture investigates the role of analogies in logical reasoning. Dr. Peikoff contrasts the idea of analogy in literature and non-fiction writing from its role in logical reasoning and explains how to analyze it as a logical tool. |