For anything to be visible to human eyes there is a condition: that its form must have a certain degree of radiance; and if it is not radiant enough or if its radiance is of a different character, then human eyes cannot see it. But this does not mean that what human eyes cannot see a human being cannot see; for the real eye is the being, and that is why man calls himself "I", saying, "I am." It is not necessary to develop insight into nature in order to experience the phenomena of a finer world, but one must see with one's eyes and perceive with one's insight in order to live a fuller life, a life of greater perfection.