THIS is Mark Twain on Bret Harte:

In the early days I liked Bret Harte and so did the others, but by and by I got over it; so also did the others. He couldn't keep a friend permanently. He was bad, distinctly bad; he had no feeling and he had no conscience.
- Mark Twain's Autobiography

Harte is a liar, a thief, a swindler, a snob, a sot, a sponge, a coward, a Jeremy Diddler, he is brim full of treachery, and he conceals his Jewish birth as if he considered it a disgrace.
- Letter to W. D. Howells, 6/1878

Harte, in a mild and colorless way, was that kind of man--that is to say, he was a man without a country; no, not man--man is too strong a term; he was an invertebrate without a country. He hadn't any more passion for his country than an oyster has for its bed; in fact not so much and I apologize to the oyster.
- Mark Twain's Autobiography

I detest him, because I think his work is 'shoddy.' His forte is pathos but there should be no pathos which does not come out of a man's heart. He has no heart, except his name, and I consider he has produced nothing that is genuine. He is artificial.
- interview in Sydney Australia Argus, 9/17/1895