In his lifetime, he proposed the rather controversial theory that wizards originally originated from the planet Mars, and that Muggles originated from mushrooms. It is unknown if he was a Wizard supremacist or a pure-blood supremacist, however his controversial theories were readily accepted by both groups as proof of the inferiority of Muggles.
Behind the scenes
- The idea of Wizards being from Mars and Muggles being from mushrooms may be referential of the phrase "Men are from Mars, women are from Venus," which was used as the title of a best-selling relationship-advice book by John Gray, and has since passed into popular culture. There is also a wizarding book titled Wizards Are from Neptune, Witches Are from Saturn.
- J. K. Rowling's official site (First appearance)