In spite of a steady tradition in the official documents of the Church, there has long existed, and still persists, much vagueness about the aims of the Missions. This has its ill-effects on the methods and on the missionaries themselves, and on the support given to the Missions by the Church at large. A clear view of the matter is therefore of the first importance.

The encyclical, Evangelii praecones, of Pius XII, issued on June 2nd, 1951, and that of his predecessor, Rerum Ecclesiae (of which the first commemorates the twenty-fifth anniversary), have given powerful directives in regard to Missions, and their prescriptions should remove many misconceptions. A more precise theology of the Missions is in the course of development, namely a branch of theology dealing with the expansion of the visible Church.

The fact which dominates the whole subject of Missions must be the purpose for which they are undertaken. Missionary activity is not synonymous with deep religious conviction as such, for there are many religions which have the character of a closed national or caste group, not easily permitting expansion beyond its limits. Such are most primitive religions, and some others such as Hinduism. Catholic Missions have a definite aim, and this has been stated clearly in the recent encyclical: ‘As everyone knows, these sacred expeditions have as their principal aim to bring the light of Christian truth more clearly to new peoples, to gain new Christians. The ultimate goal which they must strive to reach, and which must always be kept before the mind, is that of establishing the Church solidly among other peoples, and of giving it a hierarchy chosen from among the indigenous population.’ The establishment of the visible Church is the aim of the Missions.