After his release from prison in 1852 Proudhon was constantly monitored by the police, yet in 1858 he persuaded a publisher to publish his most ferociously anti-clerical and anti-religious work: De la justice dans la Révolution et dans l'église. Certainly the most subversive work of the theoretical father of anarchism, he saw in the Catholic Church an element of a destructive nature for human relations and justice. When the book appeared, he was arrested again and sentenced to three years in prison. Taking refuge in Brussels, he remained in exile until 1862 when he returned to Paris, where he died less than three years later.