34 Since the right and methodical exercise of missionary activity requires that those who labor for the Gospel should be scientifically prepared for their task, and especially for dialogue with non - Christian religions and cultures, and also that they should be effectively assisted in the carrying out of this task, it is desired that, for the sake of the missions, there should be fraternal and generous collaboration on the part of scientific institutes which specialize in missiology and in other arts and disciplines useful for the missions, such as ethnology and linguistics, the history and science of religions, sociology, pastoral skills and the like.
Source: Ad Gentes (Vatican.va)