"Publish and be damned by your cant, Polly Toynbee", shouted the headline over a Daily Telegraph piece by Barbara Amiel. Recent disagreements between Miss Toynbee and the Daily Mail (assisted by the Independent on one side and the Times on the other) had been going on nicely until then. The issue had been simple enough: was the Mail justified in snooping into Miss Toynbee's private life to find out whether it accorded with her public views? Miss Amiel very properly thought not. But that headline was a stinger.
was the Telegraph's rude word for the already much-bandied hypocrisy, and it has a good strong ring of the 18th century about it, having been famously uttered by Dr Johnson when he told Boswell to clear his mind of it. We all know the quote. But Johnson has been misunderstood here. What he said was "Clear your mind of cant", with the emphasis on "mind". Boswell shouldn't fool himself into thinking he was vexed by public affairs, he was saying. ("Public affairs vex no man.") It was perfectly all right to pretend he was, if only out of politeness. Hypocrisy is also about pretence, but of a much more discreditable kind than such mere cliche-mongering.
is more about mumbo-jumbo. It's true that even in Johnson's day the two overlapped; his own dictionary defines canter as "a term of reproach for hypocrites, who talk formally of religion without obeying it". But cant more often meant a meaningless or incomprehensible jargon. Religion came into it because cantare in Latin meant to chant, as in choirs - it was an anti-clerical remark. Then the word became associated not with cantors but with the whining of beggars, then with their private jargon, then with any sort of jargon. It certainly looks well in a headline.