Why is it that despite all the visible and touchable counter-attractions, despite the innumerable failures and long years of fruitlessness, so many men have sought through so many ages in so many lands for God, for what is utterly intangible, unnameable, shapeless, unseen, and unheard? Because the simple but astonishing fact is that the Overself, which is the presence of God in them, is part of their nature as human beings! Mysticism is nothing more than the methodical attempt to wake up to this fact. The "soul" which metaphysics points to in reasoning, mysticism establishes in experience. We all need to feel the divine presence. Even the man who asserts that he does not is no exception. For he indirectly finds it just the same in spite of himself but under limited forms like aesthetic appreciation or Nature's inspiration. Even if all contemporary mystics were to die out, even if not a single living man were to be interested in mysticism, even if all mystical doctrines were to disappear from human memory and written record, the logic of evolution would bring back both the teaching and the practice. They are two of those historical necessities which are certain to be regained in the course of humanity's cultural progress.
-- Notebooks Category 1: Overview of the Quest > Chapter 5: Self-Development > # 11