Visions are a far less plentiful phenomenon of meditation than are intuitions, inspirations, directions, predictions, and messages. Almost every mystic has them. Many may be remarkably true but others are a fruitful source of delusions; where the mystic's imaginative faculty is stronger than his critical judgement, and where it then gets to work upon metaphysical, religious, and psychological matters it cannot help falling victim to strange fantasies and deceptive chimeras. Unfortunately the mystical temperament is too inclined to indulge in undisciplined thought and to let its imagination run riot. The wishful thinker and uncritical self-deceiver quickly finds several excellent arguments to fortify his beliefs in his own mental creations.
-- Notebooks Category 16: The Sensitives > Chapter 2: Phases of Mystical Development > # 34