"To begin with, is Persian a language of equal rank with the Indian, derived from a common ancestor, or is it merely an Indian dialect? Seven centuries of linguistic development, scriptless and therefore very rapid, lie between the Old Vedic of the Indian texts and the Behistun Inscription of Darius. It is almost as great a gap as that between the Latin of Tacitus and the French of the Strassburg Oath of 842."
January 1, 1970
https://en.wikiquote.org/wiki/Persian_language