Once again we are ruled by a Dictatorship of Grief. Ever since the death of Princess Diana, we have been subject to these periodic spasms when everyone is supposed to think and say the same thing, or else. We were told on Friday that ‘politicians from all sides’ had lined up to attack Ukip’s Nigel Farage for supposedly ‘exploiting’ the Paris massacre. Mr Farage had (quite reasonably) pointed out that the presence of Islamist fanatics in our midst might have something to do with, a) uncontrolled mass migration from the Muslim world, and b) decades of multicultural refusal to integrate...