The trouble with Dr Johnson is that he is as sombre and pedantic in writing as he was, apparently, entertaining and amusing in person. It is not quite right to say, as Stevenson did, that if we had not had Boswell’s biography we should have had nothing worthwhile of him: he had a capacious mind and was an astute and sympathetic observer of humanity whether in London or the Gaelic Highlands; he was also an outstanding critic of poetry. His work is sometimes witty by his own definition, which is that of saying something which had not, perhaps, previously occurred to the hearer, but of which they immediately recognise the justice; but it is rarely witty by Pope’s yardstick, which is that wit expresses familiar ideas more aptly and neatly than they have been expressed before. His writing is heavy, it misses the seasoning of levity which need not interfere with seriousness of purpose; it has none of the ‘good things’ which Boswell reports from his conversation.
There is a short passage quoted here from Lives of the English Poets in which he discusses the defect of tediousness (not content with his great analytical intelligence, he aspired to the distinction of poet too). He says it is the worst defect a writer can have, and that it is impossible for the writer by his own judgement to assure himself he is not guilty of it. Perhaps that was the voice of his own artistic conscience.
It’s not so much that without Boswell we wouldn’t have anything of him; it’s that, without Boswell, we wouldn’t *want* anything of him. As it is he remains worth reading – if you are interested in what he is writing about. But he is not one of those whom you would read, regardless of the subject, just for the sake of keeping company with an entertaining mind.