While recent events such as the Satanic Verses affair in 1989 have led some people to think differently about the freedom of the press, most modern liberals still include freedom of speech among the ‘equal basic rights and liberties’ of Western citizenship. Unsurprisingly, considering its diversity, modern liberalism does not agree on exactly why freedom of speech should be defended. Nevertheless, from discussion of how public truth might be attained, to understandings of self-fulfilment and self-autonomy, there is a general agreement that democracy itself can only be nourished and realised by an electorate that is able to debate and to exchange ideas free from the restriction of censorship. In Alexander Meiklejohn's paradigmatic formulation, democracy and self-government ‘can only exist insofar as the voters acquire the intelligence, integrity, sensitivity and generous devotion to the general welfare that, in theory, casting a ballot is assumed to express’. And, once free speech is guaranteed, ‘individuality flourishes; once individuality flourishes, diversity arises; and once diversity arises, we can begin to assess competing visions of the good’.

Recently, though, post-modern critics have questioned how freedom of speech has been applied in the last fifty years. They have advocated for protection for religious and ethnic minorities, most obviously in the form of hate speech laws, by questioning the general applicability of Western understandings of freedom and, instead, outlining how forms of restraint and control can themselves constitute freedom and produce moral good. As the foremost proponent of hate speech laws has commented, ‘hate speech undermines the public good, or it makes the task of sustaining it much more difficult than it would otherwise be. It does this not only be intimating discrimination and violence, but by reawakening living nightmares of what this society was like – or what other societies have been like – in the past’. In turn, only by controlling offensive speech can societies produce moral good and protect the dignity of the individual.

Despite their differences over free speech and its limits both modern liberals and their post-modern critics have grounded their respective analyses in history. The most widely recognised point of departure has been John Milton's Areopagitica (1644), a work conventionally conjoined with John Locke's Letter Concerning Toleration (1689). On this reading, the seventeenth century witnessed a ferocious struggle between individual conscience and free expression against external power.