This book is about Paramatha dhamma, the natural law governing the ultimate realities, consisting of the natures of the mind, its associate factors, matter and the Ultimate Wisdom. It is a study of the Abhidhama Pitaka, one of the three Baskets of the Buddhist Teaching. The book's emphasis is on putting the principles into practice. The original work is in Myanmar (Burmese), written by the famed Abbot of Mahagandhayon Monastery of Amarapura, the southern town of Mandalay, for the purpose of teaching his 650 pupils. The book has been very popular on its native land, reprinted many times since its first publication. The translator is inspired by the book, prompting his desire to share it with readers of the English language.