The Private Memoirs and Confessions of a Justified Sinner is a first hand account of religious fanaticism as told by the fanatic, who sees his deeds as divinely inspired. It is also an account of the fanatic's mental, physical, and spiritual destruction, perhaps at his own hands, perhaps at the hands of darker forces. Its narrator, Robert Wringhim Colwan--the "justified sinner"--is consumed, in both senses, by his fanaticism.
Legally, Robert is the son of the wealthy Laird Dalcastle, but his probable father--Robert calls him "my spiritual father"--is the Reverend Robert Wringhim, a severe Puritan Calvinist preacher who serves as the Lady Dalcastle's spiritual adviser. Brought up in this strict Puritanism, Robert Jr. is well instructed in the tenets of Calvinism, which say that only the elect, those whom God has predestined, will be redeemed, and Robert wavers between a profound anxiety regarding his redemption and a snobbishness toward those he knows to be unchosen reprobates, like the Lord Dalcastle and his half-brother George.
One day, Robert meets a stranger in the woods who calls himself Gil-Martin and looks strangely like himself:
'My countenance changes with my studies and sensations,' said he. 'It is a natural peculiarity in me, over which I have not full control. If I contemplate a man's features seriously, mine own gradually assume the very same appearance and character. And what is more, by contemplating a face minutely, I not only attain the same likeness, but, with the likeness, I attain the very same ideas as well as the same mode of arranging them, so that, you see, by looking at a person attentively, I by degrees assume his likeness, and by assuming his likeness I attain to the possession of his most secret thoughts.'
What is Gil-Martin? Is he a projection of Robert's own mind? Is he, as is frequently suggested, a demon? The novel is not particularly interested in providing answers to these questions. Whatever he is, Gil-Martin has a knack for echoing Robert's own theology back to him in a way that strikes Robert as slightly askew, even as it seems to agree with him precisely. Gil-Martin helps to assure Robert of his position in the elect, and persuades him that the Lord has chosen him to "cut off" the wicked by murdering those who are not along God's elect, including his father and half brother.
Justified Sinner is a parody of antinomianism--the idea that the elect are exempt from God's moral law because they are already redeemed, and their sins cannot affect their redemption. But Robert's position in the elect looks increasingly like a membership in a group of one (or two, if you discount the fact that Gil-Martin frequently seems little more than a shadow of Robert's own self) and ultimately none, as Robert himself begins to unravel. He begins to black out, losing long periods of time where he is told that he has been doing some serious sinning, including seducing a young girl and bringing about her ruin--and possibly murdering his own mother. His self divorced, as antinomianism dictates, from his own deeds, he begins to dissolve:
Immediately after this I was seized with a strange distemper, which neither my friends nor physicians could comprehend... I generally conceived myself to be two people. When I lay in bed, I deemed there were two of us in it; when I sat up, I always beheld another person, and always in the same position from the place where I sat or stood, which was about three paces off me toward my left side... The most perverse part of it was that I rarely conceived myself to be any of the two persons. I thought for the most part that my companion was one of them, and my brother the other; and I found, that to be obliged to speak and answer in the character of another man, was a most awkward business at the long run.
Ultimately, Robert tries to run from his "companion," Gil-Martin, but he is unshakeable, because, as Gil-Martin tells him, "I am wedded to you so closely, that I feel as if we were the same person. Our essences are one, our bodies and spirits being united, so, that I am drawn towards you as by magnetism, and wherever you are, there must my presence be with you." There is no avoiding the tormentor, because Robert's tormentor may as well be himself. The final scenes of Robert's account are feverish, terrifying visions of demonic torture that directly parody the book of Revalation.
Robert's account is book-ended by "The Editor's Narrative," in which the scientific-minded Editor tries to make some sense the story. He dismisses the possibility of any supernatural truth, but his own biases hardly equal an objective take, and so the novel lies on shifting, indeterminate ground. This quality--as well as a very strange and funny cameo by the author himself as a rustic shepherd--have led some to claim Justified Sinner as a precursor to the postmodern novel.
That's a fair description--and in fact, of all the books I read for my class on the 19th-century Romantic novel, this is the one that seems most attuned to 21st Century sensibilities, and one of only two I'd say are really worth reading (the other being The Monk). But it also obscures the way that Justified Sinner is deeply invested in its own time and place, and what it meant to be a Calvinist in Scotland in the 1800's.