Stuart chose to use these category names because it is a system of strategy, not of elements, for "I am not a thing."
In the Book of Space, he offers the meta-strategy for achieving the greatest results. "To realize the principle within your own heart-and-mind, do not just read, memorize, or imitate, instead, study so as to absorb these things into your body."
From the perspective of the Chinese experiential science of Qi Gong, this strategy of bodily cultivation is called "nourishing life." So, absorb these things into your blood and energetic living field.