George Malcolm Thomson belongs to a third category: a nationalist who seemed to loathe what had happened to his country.
It's hard to think of a recent biography whose subject comes across less sympathetically. Oddly, Thomson the man scarcely comes across at all, but in this book, as in life, Thomson the scourge of between-wars Scotland comes across, comes across again, and then comes across once more, always hammering the same bleakly pessimistic vision of his native place.
Most Scots will only know the name from the dedication page of Cloud Howe; Lewis Grassic Gibbon acknowledged a debt of influence to the man who more or less invented the Caledonian jeremiad.
From the late 1920s, when he was already removed to London, to the mid 1930s, Thomson published steadily, beginning with Caledonia Or The Future Of The Scots, continuing with The Re-Discovery Of Scotland, A Short History Of Scotland, Will The Scottish Church Survive?, The Kingdom Of Scotland Restored and, lastly and perhaps most controversially in 1935, Scotland: That Distressed Area.
His most-quoted lines, though, come from the first book: "The first fact about the Scot is that he is a man eclipsed. The Scots are a dying people."
Essentially, Thomson had started out as a cultural nationalist, convinced that the great imaginative upswing of the Scottish Renaissance would kick-start a culture floundering in the demographic devastation and economic backwash of the First World War.
Disproportionately high casualty figures on the Western Front and a hitherto unsuspected infrastructural dependency on England transformed Scotland from the engine room of empire into a client outpost, forcing men and women of promise to exercise their talents south of the Tweed and Solway.
He evolved into a political nationalist, fulfilling the Balkan definition by making the Catholic Irish the main object of his hatred. Thomson saw them swamping Scotland and turning Alba into a Roman as well as English province.
He wasn't alone in making a political tool of anti-Catholicism, but unfortunately, and unforgivably, his argument was based on invented statistics and bogus 'encounters' with palpably fictional witnesses to Irish depredation of Scottish industry, politics and culture.
In the contentious Re-Discovery, he claims that between 1913 and 1928 the immigrant population of Scotland had risen by 150,000. The actual figure up to 1920 was less than 4,000. Thomson's 'thesis' is based on what one historian describes as a "manifest absurdity".
The shoddy methodology is to some degree a function of Thomson's settling in comfortable Hampstead, at a distorting distance from his subject. But he is also the perfect representation of a very modern kind of media figure, the victim of his own polemical success, whose fixed positions become so successfully branded that they are forced to become more extreme.
His publishers' enthusiastic appropriation of the 'best-hated man' tag shows how marketable it was. Thomson's ability to believe what suited his case made him not just an able controversialist but also a fine propagandist, as he showed when he later became a confidant to Lord Beaverbrook.
Far from being a revisionist life, McKechnie's is the first full-length account. However, it isn't quite strictly a biography, as the long subtitle, with its whiff of the academic thesis, implies. McKechnie has a problem in that Thomson lived on long and relatively quietly. A 20-page chapter rounds up his activities from 1940 to his death in 1996. There are between-the-lines hints - Thomson used a pseudonym for a book about whisky in order to protect his Presbyterian mother, but thought nothing of excoriating her beloved church under his own name - but McKechnie doesn't offer more than glimpses of Thomson's personality.
The Best-Hated Man works better as a background study to the rise of right-wing nationalism in Scotland. There are problems with the text. "Christopher Michael Grieve" is an unfortunate slip, on the same page as "rennaissance". But it's important work, this, on a still uncertainly understood period, and with 2014 looming, the centenary of Thomson's "red line" through Scottish history, it's powerfully relevant.