The personal contact with a master does not necessarily require a face-to-face meeting. It can also be effected through a letter written by him--nay, to some degree, even through a book written by him. For his mind incarnates itself in these productions. Thus, those who are prevented by circumstances from meeting him physically, may meet him mentally and gain the same results.
-- Notebooks Category 1: Overview of the Quest > Chapter 6: Student-Teacher > # 86