About the book: 2013 / St. Neil of Sinai (Ancyra) († about 430) - disciple of St. John Chrysostom and the great father of the Sinai desert. The book contains his moral and ascetic works: “On the Eight Evil Spirits”, “On the fact that those who remain in silence in deserts are superior to those living in cities”, “Admonition to the monks”, “Thoughts that lead a person away from the corruptible and stick to incorruptible”, “Chapters of exhortation”, “About the teacher and students”. St. Nilus of Sinai, following Evagrius of Pontius, develops a well-known classification of eight main sinful thoughts (passions): gluttony, fornication, love of money, anger, sadness, despondency, vanity and pride. His subtle ascetic-psychological analysis of these passions helps a Christian to successfully fight them and improve internally, which makes the book useful for both monastics and the widest range of Orthodox readers.