This is an extraordinary characterisation of a tough-minded woman making difficult and often flawed choices as she moves through a rags to riches story; unfortunately told as if it were a legal deposition making it overly detailed and dry despite the subject matter. Nonetheless, a remarkable book for its period.
The sub title of the book is "The Fortunes and Misfortunes of the Famous Moll Flanders, Etc. Who was born in Newgate, and during a life of continu'd Variety for Threescore Years, besides her Childhood, was Twelve Year a Whore, five times a Wife (whereof once to her own brother), Twelve Year a Thief, Eight Year a Transported Felon in Virginia, at last grew Rich, liv'd Honest and died a Penitent. Written from her own Memorandums." And that's a pretty good summary of the plot.
Moll Flanders is a composite character who couldn't possibly have had all of the adventures and experiences that she goes through in the novel. She is based on Defoe's own experiences at the lower edges of London Society, including two stretches in prison. Moll is born in gaol to a mother who has been convicted of a felony and transported to America. Moll is left behind in London to survive on charity. Learning some social skills she is taken into a middle class family where her teenage good looks bring her to the attention of first one of the sons (Lover No.1 or, in Moll's eye's, Husband No. 1) and then the other (Husband No. 2), whom she marries. So is set the tone of the book, where Moll is set a series of moral dilemmas with limited room for manoeuvre and has to square the alternatives of behaving basely against survival. She remarries when husband No 2 dies only to have No 3 run off. Faced with starvation, she hitches up to No 4 despite now being a bigamist in the eyes of the law. They move to America where she discovers that she has married and had children by her own brother and so she flees back to England where she has another affair (No. 5), and then marries No 6 - a con artist after Moll's money - but they have fooled each other since both are paupers. Despite this they fall in love but agree to separate and Moll marries (No. 7) a bank clerk who dies and leaves her penniless again. She then takes to a life of crime, becoming the most successful petty thief of her day. Eventually the law catches up with her and in prison is reunited with her con-man husband. Both are deported to America where they become rich and successful and Moll meets her son. Phew!
As you see, my count is seven husbands not five as in the introduction, but Moll herself counts her two affairs as marriage whilst Defoe apparently does not - go figure.
This is all described in minute detail and each of her dilemmas is explored and explained by Moll at great length. She is not a moral character and her reasoning is frequently about money or survival - Defoe keeps up a running commentary about how much cash Moll has at any time. She has plenty of opportunities to get back on the straight and narrow but misses them all until in prison she repents of her past deeds. Defoe isn't trying to be moral but is explaining how difficult it is for poor people to behave well if survival means they need to behave badly. There is no narrator's voice giving an opinion and the book is written as if it were a legal deposition, micro-analysing each of the scrapes and problems Moll goes through. This slows the pace and makes the work rather dry.
If you are a writer then Moll is an interesting experiment - a strong, early 18th century woman who is determined to survive at any cost. If you are a reader then the book drags somewhat so that this becomes an interesting history lesson but, despite the huge numbers of adventures, ends up a little turgid.