Naturalism was a literary movement, “born” from literary realism. Naturalistic writers were influenced by Charles Darwin’s theory of evolution. They often believed that one’s heredity and social environment largely determine one’s character. Whereas realism seeks only to describe subjects as they really are, naturalism also attempts to determine “scientifically” the underlying forces (such as the environment or heredity) influencing the actions of its subjects. Naturalistic works often include uncouth or sordid themes, exposing the harshness of life, including poverty, racism, violence, prejudice, disease, corruption, prostitution, and filth. Because of this, the writers were highly criticized. The book was a random anthology of tales, one by author, including works from Zola, Daudet, Maupassant and others. Some of them, like Daudet, never recognized themselves as part of this literary style, but they’re included nowadays.