Lucasfilm maintains that midi-chlorians were first conceived by George Lucas as early as 1977. However, there is no evidence of this before the publication of The Making of Star Wars in 2007; the book's author, Jonathan W. Rinzler, said that Lucas added the passage about midi-chlorians in the run-up to the book's publication.[20] Lucas incorporated the explanation of midi-chlorians into the film as part of Anakin Skywalker's journey towards understanding the Force.[21] When discussing the story treatment for 1983's Star Wars: Episode VI Return of the Jedi in 1981 (then titled Revenge of the Jedi), and in particular the backstory for Anakin (who had been revealed to be Darth Vader), Lucas implied that the precepts of being a Jedi could be practiced by "anyone" when comparing it to yoga or karate.[22] As recorded in Star Wars: The Making of Episode I The Phantom Menace, the midi-chlorians were incorporated into the film's story in the second screenplay draft, finished around 1995.[23] In the interview given to Paul Duncan, author of the Star Wars Archives books, Lucas confirmed that "everyone has the Force", since every single living organism has midi-chlorians inside their cells. Despite this, according to Lucas, only those with enough midi-chlorians in their body could "have a certain amount of control over our Personal Force and learn how to use it, like the Buddhist practice of being able to walk on hot coals."[24] A different explanation would be provided in the Ahsoka episode "Part Three: Time to Fly," released on August 29, 2023 in Disney+, where Ahsoka Tano assures Sabine Wren that she can become a Jedi with proper training even if she isn't Force-sensitive like others.[25]