This textbook offers a clear and detailed introduction to logic, suitable for students with no prior knowledge of the subject. Creighton presents the basic principles of formal logic, including the rules of inference, truth tables, and predicate calculus. He also discusses informal logic, and offers guidance on how to construct sound arguments and evaluate the validity of claims. The book is an essential resource for students of philosophy, mathematics, and computer science. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.