From the start of the novel, Defoe makes it clear that the unnamed editor who has worked with Moll to tell her story is an unreliable narrator, meaning that what they present as true in Moll’s “autobiography” may not necessarily be true. In the Preface, this unnamed editor communicates the following:
The Pen employ’d in finishing her Story, and making it what you now see it to be, has had no little difficulty to put it into a Dress fit to be seen, and to make it speak Language fit to be read: When a Woman debauch’d from her Youth, nay, even being the Off-spring of Debauchery and Vice, comes to give an Account of all her vicious Practises […] an Author must be hard put to it to wrap it up so clean, as not to give room, especially for vicious Readers to turn it to his Disadvantage.
Here Defoe is writing from the perspective of the one who edited Moll’s story into “what you now see it to be,” describing how he “wrap[ped] it up clean, as not to give room” for readers to misinterpret it. This raises the question: If it hadn’t been edited, what would Moll have said about her life? Would she have called her crimes “vicious Practises” or would she have been unapologetic about what she had done? All readers know is that Moll’s story has been filtered through the lens of someone else, an unnamed person who believes that Moll’s story should be read as a cautionary tale.
While Moll herself isn’t necessarily the most trustworthy narrator (as she is a con artist with a long history of changing her name and identity), the editor is the one ultimately changing her story and acting as the ultimately unreliable source of her story.