Premise: Canon John Tallis is a major character in the young adult novels of Madeleine L'Engle, appearing in four books. The character is based on L'Engle's real-life spiritual advisor, Canon Edward Nason West of the Cathedral of St. John the Divine in New York City.
Hypothesis: Canon John Tallis is a major character in the young adult novels of Madeleine L'Engle who originally wrote him as a minor character.