Deductive Logic is designed as an intermediate-level text directed at upper-division students from philosophy and the humanities. Its focus is exclusively on deductive logic, avoiding altogether topics such as informal reasoning and scientific method normally included in introductory logic courses. Its exposition of logical topics is informal, with emphasis on explaining the basic concepts and procedures of modern symbolic logic in the simplest and most intuitive manner possible rather than on developing a rigorous formal system and providing proofs of its properties. The fact that the text presupposes a course offered to philosophy students and serves to introduce them to logic as the "language of philosophy" has strongly influenced the selection of topics. The topics here are controversial, and the problems not easily resolved, but this text strives to relate the formal logical structures introduced to issues of philosophic interest.