The Doctor (Doctor Who)
The Doctor is the title character in the long-running BBC science fiction television programme "Doctor Who". Since the show's inception in 1963, the character has been portrayed by thirteen lead actors. In the programme, "the Doctor" is the alias assumed by a centuries-old alien—a Time Lord from the planet Gallifrey—who travels through space and time in the TARDIS, frequently with companions. The transition to each succeeding actor is explained within the show's narrative through the plot device of "regeneration", a biological function of the Time Lord race that allows a change of cellular structure and appearance with recovery following a potentially fatal injury.
The Doctor (Doctor Who)
In "The Mutants" (1972) an official asks the Third Doctor if he is, in fact, a doctor, to which the Doctor replies "I am, yes"; when asked what he is qualified in, the Doctor replies, "Practically everything." The Fourth Doctor states that his companion, Harry Sullivan, is a Doctor of medicine, while he is "a doctor of many things" ("Revenge of the Cybermen", 1975). The Fifth Doctor claims to be a doctor "of everything" in "Four to Doomsday" (1982), and a message to the same effect is related from the Tenth Doctor in "Utopia" (2007). In talking with Harry in "Robot" (1974–1975) the Doctor states "You may be "a" doctor, but I'm "the" Doctor. The definite article, you might say." In "The Ark in Space" (1975), aired later that year, the Doctor states that his doctorate is only honorary; the Tenth Doctor, however, considers the name to be his legitimate academic rank in "The Waters of Mars" (2009), describing his "name, rank and intention" as "The Doctor; doctor; fun." In an interview with "The Age" in 2003, Tom Baker mentioned that the Doctor is called so because he is "a doctor of time and relative dimension in space". Apart from being called a doctor of the TARDIS, the Doctor has been referred to as a "doctor of time travel."