 Realism reached its maximum splendor in the second half of the 19th century with authors such as Juan Valera, José María de Pereda, and Benito Pérez Galdós, although it never established a canon as rigorous as that produced by the school of Balzac.Naturalism in Spain, as it did in France, also had its detractors, sometimes provoking great controversies.Naturalist Pedro Antonio de Alarcón carried on a fierce rivalry with José María de Pereda who, impassioned, once described Realism as "immoral".