There are mystics who have developed a considerable depth of meditation. They come back from their session of practice feeling the peace they have touched, but at the same time they come back smugly satisfied with the experience and especially with the attainment it seems to point towards. This is not enough. Even if they go apparently to the apex of the stillness, the ego has travelled with them. They may be aware of where they have been, but they were aware that they were aware. Thus there was duality in what they thought was unity. Do not praise the ego for having found God. It was Grace which brought about the discovery. It was not the ego. It is true that the beginner needs humility but it is even more true that the advanced man needs even more humility.
-- Notebooks Category 18: The Reverential Life > Chapter 3 : Humility > # 42
