The most effective method of propagating spiritual truth in this modern age is undoubtedly the radio. The printed word can only be a secondary medium. But propaganda is not quite the same as education. Radio propaganda is the most effective of all methods for bringing new ideas to people who have never heard them before, and for inspiring individuals with right feeling and enthusiasm. But the printed word is necessary where deep thinking and repeated reflection are required in order to master difficult points. Therefore the awakening of unenlightened people and the encouragement of enlightened beginners to spiritual truth is best done through the radio, but the instruction and assistance of more advanced students is best done through the printed word. An adequate scheme should cover both methods. The printed word is essential chiefly for the intermediate and advanced students who are scattered in various parts of the world in loneliness and isolation and who have no personal teacher to instruct them.
-- Notebooks Category 12: Reflections > Chapter 2 : Philosophy and Contemporary Culture > # 46