One night when I was very young I was crossing a bit of wasteland in Sheffield when I said to my companion, “I never leave a book unfinished.” Struggling to explain myself, I added, “The author has gone out of their way to try and tell me something –to express something – it seems wrong not to read their book.” “That’s as deep,” returned my companion in broad Scouse, “as a muddy puddle.” For these were the sort of young men I went to university with. Since then I have discovered, sadly, that there are unreadable books. It isn’t necessarily that the books are “bad”, though it might be. Occasionally a book is so bad I’ve flung it against a wall; once I even trampled on one. (And no, I won’t tell you which it was. It might be your favourite.) To qualify for this thankfully rare treatment a book must exhibit something cynical in the workmanship. It will be a smug, complacent, passionless piece characterised by sloppy thinking and lazy writing. But most books have something to offer and...