This book is planned as an introductory logic design book for students in commerce and management sciences. This book fulfills the primarily needs of the students of the business administration, commerce and management because Logic and critical thinking is an important management course. The book stresses fundamentals. It covers basic approaches of Logic. Logic and critical thinking is the key essential for the success of any Organization, Because most of the Managers need to make decisions, good and sound decision choice needs to understand the basics of Logic and Critical Thinking, which help the managers in their decision making process. This book describes the important concepts that make up the field of Logic and also emphasizes active learning through basic concepts in each chapter. The book is equally useful for those persons who are managing their organization and want to know the basic of Logic.Since several books already available in this subject but the main objective of this book is to assisting the students to understand the preliminary of the Logic.That's why this book is written in easy and self teaching style.