In short, if you want to improve a person in a certain spect, act as though that particular trait were already one of his or her outstanding characteristics. [...] And it might be well to assume and state openly that other people have the virtue you want them to develop. Give them a fine reputation to live up to, and they will make prodigious efforts rather than see you disillusioned.
(November 24, 1888 – November 1, 1955) was an American writer and lecturer and the developer of famous courses in self-improvement, salesmanship, corporate training, public speaking and interpersonal skills. Born in poverty on a farm in Missouri, he was the author of How to Win Friends and Influence People, first published in 1936, a massive bestseller that remains popular today. He also wrote a biography of Abraham Lincoln, entitled Lincoln the Unknown, as well as several other books.