Observation is developed by singleness of glance. For instance, if I look at a person I can see that one person much better than if I look at many people, and it is thus with everything in life. The first step in learning mysticism is just this: to develop our observation. We are always looking at a hundred things around us, and hardly ever study one thing properly at all. To understand and know a thing better we must keep looking at it; if we keep looking at everything we look at nothing. Such is the law of observation.