On Liberty, first published in 1859, John Stuart Mill famously laid out four reasons for why free speech was a necessity in a free society: the first and second being that a contrary opinion may be true, or true in part, and therefore may require to be heard in order to correct your own erroneous views; the third and fourth being that even if the contrary opinion is in error, the airing of it may help to remind people of a truth and prevent its slippage into an ignorant dogma which may in time – if unchallenged – itself become lost.2
Abiding by Mill’s principles would appear to be hard for many people today. Harder, indeed, than simply changing dogmas. In recent years the accepted opinion on gay rights in America, Britain and most other Western democracies has shifted unimaginably, and for the better. But it has moved so swiftly that it has also seen the replacement of one dogma with another. A move from a position of moral opprobrium to a position of expressing opprobrium to anyone whose views fall even narrowly outside the remit of the newly adopted position. The problem with this is not just that we are at risk of being unable to hear positions that are wrong, but that we may be preventing ourselves from listening to arguments that may be partially true.