Mr. Mister, in its contracted form, Mr. Mister, Mr. Mister, Mr. Mister, Mr. Mister, Mr The title "Mr." was derived from older versions of master, just as the analogous feminine titles "Mr," "Miss," and "Ms." were all derived from earlier forms of mistress. Master is still used as an honorific title for boys and young men. It comes from the Latin word for "teacher" or "guide." A person who has a master is called a "servant." The use of "Mr." before a man's first name is common in England. For example, "Mr. Dickens" (George Charles Nicholas) was an acclaimed author of novels for children and adults. He has been called "the father of modern fiction." "Mr. Einstein" is considered to be one of the most important physicists of all time. He developed theory of relativity with his famous friend and collaborator, Dr. Schrödinger. The use of "Dr." before a man's last name is a formal courtesy adopted by doctors themselves. However, it is not necessary for someone else to be a doctor for you to use it. For example, "Dr. Jekyll" is a character in Robert Louis Stevenson's novel, The Strange Case of Dr. Jekyll and Mr. Hyde. "Mr. Smith" can be addressed as "Dr. Smith" because he is a scientist. However, it is not necessary for him to have a degree in science to be called "Dr. Smith".