Integrism was a Spanish political philosophy of the late 19th and early 20th century. Rooted in ultraconservative Catholic groupings like or Carlists, the Integrists represented the most right-wing formation of the Restoration political spectrum. Their vision discarded religious tolerance and embraced a state constructed along strictly Catholic lines; the Integrists opposed Liberalism and parliamentarian system, advocating an organic regime. Led first by Ramón Nocedal Romea and then by Juan Olazábal Ramery they were active as a political structure named Partido Católico Nacional (also known as Partido Integrista), but the group retained influence mostly thanks to an array of periodicals, headed by the Madrid-based El Siglo Futuro. Though Integrism enjoyed some momentum when it formally emerged in the late 1880s, it was soon reduced to a third-rate political force and eventually amalgamated within Carlism in the early 1930s.
The role of religion and the Roman Catholic Church has been a point of heated political debate in Spain since the Napoleonic era, with waves of secularization and de-secularization following each other as the country was undergoing a half-century long, turbulent period of political instability. During declining years of the Isabelline monarchy of the 1860s different breeds of Liberalism sought to curtail the position of the Church still further. They were most vehemently opposed by two political groupings, both considered Integrist predecessors.
The so-called neocatólicos was an intellectual movement initiated during the early Isabelline years; its founding fathers, Juan Donoso Cortés and Jaime Balmes, tried to accommodate orthodox Catholicism within a framework of the liberal monarchy. With leaders like Antonio Aparisi, , , and Ramón Vinader, in the 1860s the neos strove to save the crumbling rule of Isabel II by building a grand, ultraconservative Catholic party. Their project crashed during the Glorious Revolution of 1868; in the early 1870s they concluded that the Liberal sway can no longer be confronted by constitutional monarchy and that a more radical response is needed.