The amount of information offered here is both the book's strength and its weakness. On the one hand, it encompasses material that in some cases is otherwise unavailable in Eng-lish or even in romanized Pali, and should be sufficient to serve as a life-long companion to any bhikkhu who seriously wants to benefit from the precise and thorough training the rules have to offer. On the other hand, the sheer size of the book and the mass of details to be remembered might prove daunting or discouraging to anyone just embarking on the bhikkhu's life.

To overcome this drawback, I have tried to organize the material in as clear-cut a manner as possible. In particular, by analyzing each rule into its component factors, I have tried to show not only the rule's precise range but also how it connects to the general pattern of mindfully analyzing one's own actions in terms of such factors as intention, perception, object, effort, and result -- a system that plays an important role in the training of the mind.

Secondly, I have provided short summaries for the rules and have gathered them, organized by topic, in the Rule Index at the back of the book. If you are new to the subject of Buddhist monastic discipline, I suggest that you read the Rule Index first, to grasp the gist of the rules and their rela-tionship to the Buddhist path, before going on to the more detailed discussions in the body of the book. This should help you keep the general purpose of the rules in mind, and keep you from getting lost in the mass of details.

I am indebted to the many people who helped directly and indirectly in the writing of this book. Phra Ajaan Fuang Jotiko (Phra Khru Nanavisitth) and Phra Ajaan Thawng Candasiri (Phra Nanavisitth), my first teachers in Vinaya, gave me a thorough grounding in the subject. Ven. Brahmavamso Bhikkhu gave many hours of his time to writing detailed criticisms of early versions of the manuscript during the long period of research that led up to the book, forcing me to deepen my knowledge and sharpen my presentation of the topic. There was a brief period when he and I thought of co-authoring the book, but the many questions that needed to be settled concerning form and content eventually required that one person go it alone, and it fell my lot to be that person. Still, much of the precision of the book is a result of his efforts, even in cases where I had to differ with his opinions.

As the manuscript began to approach its final form, Ven. Phra Nanavarodom, Bhikkhu Bodhi, Thiradhammo Bhikkhu, Amaro Bhikkhu, Suviro Bhikkhu, Bill Weir, and Doris Weir all read copies of it and offered valuable suggestions for improvement. I, of course, remain responsible for any errors it may still contain.

I dedicate this book in gratitude and respect to my preceptor, Phra Debmoli (Samrong Gunavuddho) of Wat Asokaram, Samut Prakaan, Thailand, and to all my teachers in the path of the Dhamma-Vinaya.

Thanissaro Bhikkhu
(Geoffrey DeGraff)