"Coventry" is a science fiction short story by American writer Robert A. Heinlein, part of his Future History series.
In a future American society, everyone must accept the Covenant of non-violence, and psychologists can "cure" criminal or violent personality traits.
The protagonist, David MacKinnon, is a romantic idealist who has been convicted of assault, and the court determines he is a substantial risk to commit violence in the future.
It is actually a bleak dystopia split into three separate "countries": On arrival in New America, MacKinnon is arrested and jailed, and loses everything he had brought with him through the Barrier.
On March 8, 1949, fellow science-fiction author L. Ron Hubbard wrote to Heinlein referencing Coventry as an influence on what would become Dianetics: Well, you didn't specify in your book what actual reformation took place in the society to make supermen.