Electric Shepherd by Karl Miller

"Gie me an unce o' opium, Mr De Quinshy," says the Ettrick Shepherd, James Hogg, in one of the 70-odd Noctes Ambrosianae: imaginary conversations which enhanced the popularity of Blackwood's magazine. Hogg himself contributed to them, but the Ettrick Shepherd, a regular voice from 1822 to 1835, was Hogg's semblable, with his dialect, quickness, earthiness, gluttony, sexual appetite and downrightness. More than one member of the Noctes group could work the Ettrick puppet in prose and verse.

The former shepherd Hogg (1770-1835) became famous, as a personality and writer. He regarded himself as Burns's heir. His mother was a strong-willed singer of ballads and tales, and he retained the burr and the manner of a countryman. No matter how well-dressed he was, Edinburgh city clothes never convincingly fit him. Scott and Byron, Murray and Lockwood, were able to put up with him because, volatile though he was, unpredictable, moody, undependable, he was somehow authentic. Custom and class never reduced him to easy obedience.

Hogg's great work is his autobiographical novel, Private Memoirs and Confessions of a Justified Sinner (1824). André Gide in the 1940s advocated it at Oxford, first forgetting and then speaking aloud the name of "M. 'Ogg".

Karl Miller's "likeness" of Hogg is another approximation, attempting to square the peasant-born writer, his fiction and autobiography, and his fictionalisations. Miller aims to reconstitute the amazing Mr Hogg from the contradictory refractions of the life and work. In the Noctes we witness our Esau-fleeced shepherd swimming nude off Portobello, deep in conversation and in the sea. With the bailiffs virtually at the door, he and another debtor set off in a balloon to the moon. The exaggerations of fiction never lie; they clarify truth.

Miller is drawn to Hogg in part for personal reasons. He grew up between Hogg's Lowland landscape and Edinburgh, and learnt about Hogg from his grandmother. Hogg and his writings are a part of him for which he feels affection and annoyance. He tells how Hogg, a real shepherd, "drove his pastorals to market". He recalls the tender brutality of Hogg's account of castrating sheep. And Hogg was part of the world of 19th-century Edinburgh journalism that Miller evoked so raptly in his second volume of autobiography, Dark Horses.

Hogg edited a magazine, The Spy. It was stigmatised for "indecency" and had no compunction about borrowing material. Any writer whose work was known could be parodied, plagiarised or imitated. Journalism was ad hominem, whether its purpose was to analyse or entertain. In the end Hogg threw in his cap with Blackwood's, though like most freelances was not averse to the occasional, often contentious, infidelity. As he grew famous so his hubris grew.

Miller's Hogg is an "apostle of duality". Duality is Miller's hobby-horse: Doubles, his critical exploration, is binary to the point of obsession. His radicalism was long ago arrested at paradox, without the vigour to pass on to dialectic. Later, Hogg is "an aggregation of dualities", and the self-qualifying nature of his writing makes him a rural Abelard in philosophical terms. An irony Miller does acknowledge is that Hogg ended up giving sermons, though his theology was undistinguished.

The Ettrick Shepherd caught the literary bug when he first heard Burns's "Tam o' Shanter". The freedom of expression that Scots dialect provided, the way it could move in an instant from deep feeling to satirical verve, showed Hogg how he might be in verse and prose. Miller has to allow for some poor writing, part of the context for Hogg's best work.

Miller organises the book "both chronologically and thematically". Chapters run through several decades, concentrating on a few subjects; time-scales overlap, there are repetitions. Miller sacrifices narrative for thematic coherence. His Hogg himself remains Protean even as the figures around him are defined and refined.

The best parts of Electric Shepherd are devoted to the key editors and journalists, John Wilson and John Gibson Lockhart among them. There is fidelity in the portrayal of the attendant players. As they become defined, the indefinition at the heart of the book, the "likeness" of Hogg, becomes a matter of amused frustration.

Miller is in love with details, their double valency. Damn the wood, he seems to say: what matters is the trees.

Michael Schmidt's 'Lives of the Poets' is published by Phoenix