"One of the major functions of the Masters is to convey the principles of the Plan to their less evolved brothers. The usual technique employed for this purpose is impression. So far the Masters have not taught from public platforms, but have mainly worked on intuitive and mental levels, by telepathically impressing ideas on the minds of their disciples. However, as more of these Masters make their appearance among men, and recognition of their powers and wisdom grows, it is possible that use will also be made of oral teachings, when they might avail themselves of radio and television facilities."
January 1, 1970
https://en.wikiquote.org/wiki/Masters_of_Wisdom_(Theosophy)