Who can define "the decencies of controversy ?" Everyone has his own criterion in such matters, which is usually unconscious and fluctuating.
What shocks one man pleases another.

Does not the proverb say that one man's meat is another man's poison?
Lord Coleridge reduces Blasphemy to a matter of taste, and _de gustibus non est disputandum_.

According to this view, the prosecution has simply to put any heretical work into the hands of a jury, and say, "Gentlemen, do you like that?
If you do, the prisoner is innocent; if you do not, you must find him guilty." Such a law puts a rope round the neck of every writer who soars above commonplace, or has any gift of wit or humor.

It hands over the discussion of all important topics to pedants and blockheads, and bans the _argumentum ad absurdum_ which has been employed by all the great satirists from Aristophanes to Voltaire.
When Bishop South was reproached by an Episcopal brother for being witty in the pulpit, he replied, "My dear brother in the Lord, do you mean to say that if God had given you any wit you wouldn't have used it ?" Let Bishop South stand for the "blasphemer," and his dull brother for the orthodox jury, and you have the moral at once.
"Such a law," says Sir James Stephen, "would never work." You cannot really distinguish between substance and style; you must either forbid or permit all attacks on Christianity.

Great religious and political changes are never made by calm and moderate language.