As early as 1878, Pope Leo XIII's encyclical Quod Apostolici Muneris strongly denounced Socialism--however Christian--on the grounds that it opposed the natural institutions of authority and property, preferring to substitute forcible governmental distribution of goods for charity.
Quod Apostolici Muneris: Encyclical of Pope Leo XIII on Socialism.
Among the most important encyclicals are: Inscrutabili Dei Consilio, "On the Evils of Society," 1878; Quod Apostolici Muneris
, "On the Evils of Socialism," 1878; Aeterni Patris, "On the Restoration of Christian Philosophy," 1879; Arcanum, "On Christian Marriage," 1880; Diuturnum, "On the Origin of Civil Power," 1881; Immortale Dei, "On the Christian Constitution of the State,"1885; Libertas, "On the Nature of Human Liberty," 1888; Exeunte lam Anno, "On the Right Ordering of Christian Life," 1888; Sapientiae Christianae, "On Christians as Citizens," 1890; Rerum Novarum, "On Capital and Labor," 1891; Graves De Communi Re, "On Christian Democracy," 1901.
Such legislation is merely the natural outgrowth of the socialist mindset, which Pope Leo XIII warned against in Quod Apostolici Muneris
, his encyclical of 1878.
Leo XIII, who succeeded Pius in 1878, shared his predecessor's evaluation of the contemporary world, as is clear from his second encyclical, Quod Apostolici Muneris
(1878): "The revered majesty and power of kings have won such fierce hatred from these seditious people that disloyal traitors ...