It is necessary to enforce limits to free speech for legal consistency, so that incitement to crime is itself a breach of the law.
Crime prevention is a key aspect of legal power: preventing murder is clearly better than just focussing on catching and punishing the criminal, so it is logical to prohibit people from inciting others to commit a crime. Although the crime itself has not yet been committed, the incitement makes it more likely to occur. Thomas Scanlon, in A Theory of Freedom of Expression, identified examples of battery, assault, defamation, conspiracy and incitement where freedom of speech would not necessarily provide a defence. [pp. 158-159]
The Economist reported on one notorious example, The mosque at Ayodhya, of impunity in the absence of limits to free speech for legal consistency. Destroying the mosque was clearly illegal, but the Indian BJP leader, Mr Advani, could not be prosecuted for incitement:
“[a]fter whipping up his followers, he and several other senior BJP leaders looked on as the mosque was razed with pickaxes and bare hands.”
The rule of law is undermined in its entirety if it lacks self-consistency.
(This is an archive of a page intended to form part of Edition 4 of the Patterns of Power series of books. The latest versions are at book contents).