%0 Book %A Catholic Church. Pope (1958-1963 : John XXIII) %I Catholic Truth Society %D 1963 %C London %G English %T Encyclical letter : Mater et magistra of His Holiness John XXIII by Divine providence Pope to the venerable brothers the patriarchs, primates, archbishops, and other local ordinaries in peace and communion with the Apostolic See, and to the clergy and faithful of the entire Catholic world concerning a re-evaluation of the social question in the light of Christian teaching.