Roberto Bolano configures the concept of the ‘servile will’ in By Night in Chile, where the same character is who offers his freedom and who voluntarily submits under the servitude of the dictatorial State. Father Sebastian Urrutia, since his double role as the narrator and the protagonist, submits himself as a voluntary servant to the evil represented in the dictatorship. First, we will compare Bolano’s novel with The Feast of the Goat by Mario Vargas Llosa, with the aim of highlighting the particular meaning of Bolano’s writing. While the Peruvian novel shows the problem of the free will, the concept of the servile will is developed in the Chilean novel. Both novels are about the dictatorship and were published in the year 2000. Secondly, we will compare Bolano’s novel and Under the Sun of Satan by Georges Bernanos, in order to emphasise the origin of the sin as a representation of the evil. We will demonstrate that in the Bolano’s novel the sin as a source of evil might have its origin in the reading cited about Bernanos by Bolano. Bernanos, who was a Catholic writer, in his novel also there is as protagonist a priest who faces the eschatological Evil. With regard to theoretical support, we will consider the concept of the servile will that comes from Martin Luther, confronted with the free will of the Thomas Aquinas. Contemporarily, Paul Ricoeur has revised the concept of the servile will from the point of view of the fragility of the human-nature, as part of the symbolic of evil.