In ancient India, learning spanned four quarters of one’s life. Learning was sought from the teacher, from one’s individual effort, from fellow students and in the last quarter, from the school of life itself. This book belongs to the third quarter for students of Āyurveda regardless of their background in medicine, science, or humanities. Apart from topics in the eight branches of Āyurveda, the book also deals with Āyurvedic Biology which seeks to study the concepts and procedures of Āyurveda with the tools of modern biology.