Critical thinking is reflective and reasonable thinking that focuses on deciding what to do or believe. Principles Critical Thinking such as Critical thinking is a learnable skill; the instructor and peers are resources in developing critical thinking skills and Several courses, particularly those that teach problem solving skills, nurture students' metacognitive abilities. Approaches to defining critical thinking that reflect their respective concerns. Critical thinking relies on foundational skills such as good reasoning, critical reading and analysis, and critical writing including note taking. The book ¿Thinking and Critical Thinking¿ includes four chapters namely Think and Thinking Skills in first Chapter, Second Chapter included Nature of Critical Thinking, Third Chapter explored Critical Thinking and Education and last chapter discussed Critical Thinking and Disciplines. References have been given in the last part of the book. I hope that this book will be useful to students and teachers of primary, secondary, higher secondary schools and colleges of University. This book will be very useful to P.T.C.,B.Ed. and M.Ed. students too.