My mother was a woman of fiercely expressed opinions - that the state should seize the commanding heights of the economy, that the Hungarians had it coming in 1956 and that she didn't know the meaning of the word sarcasm. The problem with the last one was that we, as her family, were never sure she wasn't lying when she said it. Certainly she often said things that sounded suspiciously sarcastic - 'I love it when everyone argues around the table' for example - but she continued to deny, until her dying day, that she even knew the meaning of the word.
I found myself in a similar quandary when reading the excellent and hilarious Dairy of a Fleet Street Fox. In one chapter the Fleet Street Fox (in character) goes into an extended diatribe about how, in modern society, nobody, not politicians or members of the public, will take responsibility for their actions. There is at least a page and a half (it's hard to tell with a kindle) of this with named examples and how this trend to 'twatishness' is growing worse.
Then, practically one page later, she does an equally long diatribe about how if journalists are racist, misogynistic, misanthropes it's not their fault because these traits are forced on them by repeated exposure to the venality and stupidity of the public. Now if the irony of this juxtaposition is lost on you then I commend for the Order of the Baldrick and suggest you probably read something else.
My problem is I can't tell whether the Fleet Street Fox is being ironic or not or whether she totally wrote the passages without being aware of the hypocrisy that underlies them. Now I think she's being ironic but like with my mum I suspect I'm never going to know for sure.