According to Phelps, Pope Leo XIII advocated a corporatist view in his 1891 encyclical Rerum Novarum, and Pope Pius XI amplified these ideas in his 1931 encyclical Quadragesimo Anno.
Selon Phelps, Léon XIII aurait promu une vision corporatiste dans son encyclique de 1891 intitulée Rerum Novarum, le pape Pie XI ayant amplifié ces idées dans son encyclique de 1931, Quadragesimo Anno.