The Miniature Guide to Critical Thinking - Concepts and Tools This miniature guide, which has sold more than half a million copies, is widely used in teaching and learning, in personal and professional life. It distills the essence of critical thinking into a 24-page, pocket-sized guide. It introduces the interrelated complex of critical thinking concepts and principles implicit in the works of Richard Paul and Linda Elder. This guide is widely used at the college level. It can be used as a critical thinking supplement to any textbook or course.