The papal encyclical letters express the pope��s mind normally on matters of faith and morals. Apostolic exhortations often concern similar topics but do not define doctrine and are normally directed at encouraging certain groups within the Church to certain activities. In recent decades apostolic exhortations have most often been issued at the conclusion of synods of bishops and have served as the popes’ summations and interpretations of those synods’ conclusions. Together with encyclicals, apostolic exhortations are the most important documents produced by the Holy See, touching all matters of ecclesiastical government and doctrine.