This book gives many fundamental principles for nonfictional writing. The core principle of all is to write in a concise, clear and warm way with intelligence, humour and humanity. A good essay should be loyal to the writer and be friendly to the audience. A good essay should be full of freshness and surprises. A good essay should be logically linked between every two parts without redundancy. All in all, to write well is to make a sincere and enjoyable conversation.