If you ask me,
the Encyclopedia Britannica's article, and its arrogance, are all about defensiveness and embarrassment, which have weakening effects.

This has not been an opportune time for me to attempt to read
D. S. Thomson's book, and the copy will have to be returned
to the lending library soon enough.

What I have seen Thomson do, in the chapters that I have skimmed,
is to compare and contrast two distinct types of literature:
the Gaelic sources, especially the Scottish Gaelic as he could locate it, but failing that, the sources that are Irish;
and Macpherson's own English.

I may be mistaken here, but it is my understanding that
the published James MacPherson Gaelic-language Ossian --
yes, there was indeed such a product in the marketplace --
was a "back-translation" and owed everything
to MacPherson's English, and next to nothing
to the authentic source material.
Don't ask me who translated Macpherson's English-language Ossian into Gaelic, though, because I don't even know where to look for that answer ... for obvious reasons,
back in the day, the culprit was hidden.

Well, I suppose the perception of this event is permanently colo[u]red
by the sheer notoriety in the publishing business,
and the incautious readers, students, and even lecturers and scholars.
It is small wonder if a whole generation, not to speak of a whole century, of persons had much to be embarrassed about.


So, what did I notice about Thomson in his book's comparison
of the Gaelic / archaic source material with James Macpherson?

There is no irony, sarcasm, or archness whatever in his comments.
He will look at one ancient account and
relate how spare and economical the description is.
Then he will state that Macpherson totally covered the whole story
in the most embarrassingly overdone emotion and purple language,
entirely at odds with the original.

Thomson will also note if Macpherson
keeps intact such details as are vouchsafed in the Gaelic,
such as proper names,
or if he alters names of persons, places, and things;
the same applies to the events and actions described.
Thomson does this with the calm efficiency
of someone who has devoted no small amount of trouble
to grasping -- whether or not mastering -- the Gaelic tongue itself.
I recommend the book,
even if I can't read it closely or describe it well.