'There’s a sweet response to 10-year-old Nicholas Greaves, who in 1988 asks le Carré for tips on becoming a spy. “To be a spy, you need first to know what you think about the world, whom you would like to help, whom to frustrate,” le Carré responds. “Also, you have to decide how much you are prepared to do by dishonest means.”

https://www.nytimes.com/2022/11/30/books/lecarre-book-letters.html