Moreover, it has pragmatic virtues. Racists might examine their prejudices
The limits of free speech in South Africa
Duncan McLeod

Hate speech, like any other form of intellectual contagion also has pragmatic vices, such as infecting new minds and mutating the minds of others against it. Only if the immune system if societie’s intellect is stronger than the contagion can exposure to hate speech have a nett positive effect, don’t you think?