With the expansion of the discipline of public administration, the need for literature on administrative theory is being increasingly felt. This book is an attempt to fill this gap; albeit in part. The book provides an account of the ideas and contributions of twenty-one thinkers to the discipline. Each chapter covers an outline of the thinker's life, writings, principal contribution to the theory and a critical evaluation. This volume is weaved together with the contributions of twenty-one teachers who have had vast experience in the study and teaching of public administration, political science, sociology and management. It offers a single source of reference on the theory of public administration; particularly the contribution of select thinkers. In this second and revised edition one chapter on administrative theory and two thinkers have been added. All chapters have been revised. Over the years the book gained recognition and has become a compulsory reading to the students and scholars of public administration. It is also an important source book for those appearing for the competitive civil service examinations at national and state levels in public administration and management. D. Ravindra Prasad, PhD was professor of public administration and Director, Regional Centre for Urban and Environmental Studies, Osmania University. He is currently working as Advisor, Urban Governance, Administrative Staff College of India, Hyderabad. V.S. Prasad, PhD was formerly Project Director, Open University, Mauritius. He was earlier Director, National Assessment and Accreditation Council, India; Pro-Vice-Chancellor, Indira Gandhi National Open University, New Delhi and Vice-chancellor, Dr. BR Ambedkar Open University, Hyderabad. P. Satyanarayana, PhD was Director, Regional Centre, IGNOU and worked as Deputy Director, Southern Regional Centre of Indian Council of Social Science Research, Hyderabad.