This volume is a translation from original Pali into English of Dhamma-Sangani, the first book of the seven books of the Ahidhamma-Pitaka. The Dhamma-Sangani is an important text of the Theravadin School of Buddhism and deals with the enumeration of the psychic and mental properties, i.e., the elements and objects of consciousness and constitutes an important work from the point of view of psychological ethics. It is a Buddhist manual of psychological ethics and provides an 'enumeration of the Dhammas', i.e., an inquiry into the mental elements or processes. It is a compendium of the terms and concepts in vogue among the Buddhists and the Import and meaning of which have been made clear for those striving to attain the Buddhist ideal of Arahat-ship. The book is divided into three main sections containing the Genesis of Thoughts, Form and the Division Entitled 'Elimination'. The learned author has not simply rendered a literal translation of this difficult text but has added copious notes to the text and has also tried to connect the Manual with the rest of the Buddhist Pitakas. In her Introductory Essay, she has discussed with great erudition, the relevant portions regarding the historical traditions, the commentaries on the subject, Buddhist psychological ethics and the fundamental concepts such as those relating to mind, and theory of intellection, and Buddhist notions of good, bad and indeterminate. A glossary of Pali words and a general index have enhanced the value of the book.