Intermediate Logic - Textbook (old)

Newer edition available.

James Nance, Logos School's Logic instructor, has refined this course over his many years at the school. Covering topics in logic too often reserved for a college course, this text simplifies formal proofs and truth trees for propositional logic. For the 8th grader and up. The Answer Key is highly recommended as a complement to this item!

Logic is the art of reasoning well—of learning to think God's thoughts after Him. In this book, James Nance builds on the foundation of Introductory Logic for Christian and Home Schools to help students explore the more challenging terrain of formal, propositional logic.

First, students are introduced to propositional logic, logical operators, and truth tables, while reviewing and reapplying the concepts of validity, contradiction, consistency, and equivalence. Next they learn to construct formal proofs of validity by using basic rules to derive an argument's conclusions from its premises. Finally, students discover how they can use the technique of "truth trees" to determine consistency, self-contradiction, tautology, equivalence, and validity.

This text, together with Introductory Logic, provides students with a rigorous course in logic that will help them excel in every other subject they will study, from math and science to rhetoric and the humanities. Extensively revised and updated, with additional review questions and exercises for each unit, this book is an essential part of every Christian school or home school curriculum.

Changes in the 2nd Edition

This curriculum has been changed in a number of critical areas:

• First, in order to present to the student a more logical progression of topics, the section on defining terms has been moved from Intermediate Logic to Introductory Logic, where it is taught along with other branches of informal logic and categorical logic.
• Second, review questions and review exercises have been added to each unit for every lesson in the text, effectively doubling the number of exercises for students to verify their knowledge and develop their understanding of the material. Additionally, some especially challenging problems have been included in the review exercises.
• Third, the definitions of important terms, key points made, and caution signs regarding common errors are now set apart in the margins of the text. This should help students to distinguish the most important topics, as well as aid in their review of the material.
• Fourth, every lesson has been reviewed in great detail with the goal of improving the clarity of the explanations and correcting several minor errors that were found in the original edition.
• Fifth, the book is now in a handsome perfect-binding, with all exercise pages perforated for easy removal.