A pyramid of souls exists, based on the desire to receive. At the base of the pyramid are many souls with small desires, earthly, looking for a comfortable life, animal-like: food, sex, sleep. The next layer comprises fewer souls, those with the urge to acquire wealth. These are people who are willing to invest their entire lives in making money, and sacrifice themselves for the sake of being rich.
Next are those that will do anything to control others, to govern and reach positions of power. An even larger desire, by fewer souls, is for knowledge, scientists and academics who spend their lives engaged in discovering something specific. They interested in nothing but their all-important discovery. The strongest desire, developed by only a few, is for the attainment of the spiritual world. They are all built into the pyramid.