The recent debate prompts me to put it in proper context, and to avoid the confusion that inevitably arises when the discussants claim that "the real Harriet Smith" did this or that.
The core premise of my shadow story theory that I first clearly articulated 10 years ago is that there are two independent, coherent, parallel fictional universes in each Jane Austen novel -and so there is a Harriet Smith who is naive like Richardson's Pamela and a Harriet Smith who is Machiavellian like Fielding's Shamela. Jane Austen deliberately wrote Harriet's character so that she could be read in two completely opposing ways. And the same is true of many of Austen's major characters in all of her novels.
So, I claim that there is not merely one real Harriet Smith, there are TWO!
And Jane Austen being a creator of puzzles and mysteries who played fair with her readers, she left many clues to this double anamorphic structure in her writing, but the most important one is the two-stanza charade in Emma, with its one "official" answer (courtship), and its numerous additional answers (Prince of Whales per Sheehan, Leviathan per Anielka, Crown of Thorns per me, and others).
It is Jane Austen's central symbol of this anamorphism, and truly is her "Rosetta Stone". I.e., each novel is a complex charade which has one official "answer" and (at least) one other "answer", depending on whether you read with the grain (reading the narration as mostly objective) or against The grain (reading the narration as mostly subjective, filtered through the clueless eyes of the heroine).
Getting back to Harriet Smith, I am of the party who believe that Shamela was not Fielding's original invention, but rather was Fielding's discovery of Richardson's own sly deliberate anamorphism.
And, in turn, Richardson and Fielding appear to me to have been inspired by Shakespeare's widespread use of anamorphism in many of his plays. And Shakespeare, in turn, learned this from Chaucer and the Greeks, in a great chain/tradition of covert literary emulation.
And finally Jane Austen, like Mozart in music, learned from all who came before her, but she then took this anamorphism to a level of genius and perfection never equalled before or since.
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