To understand more precisely the process of confirming the solidity of I and other, that is, the development of ego, it is helpful to be familiar with the five skandhas, a set of Buddhist concepts which describe ego a five-step process.
The first step or skandha, the birth of ego, is called "form" or basic ignorance. We ignore the open, fluid, and intelligent quality of space. When a gap or space occurs in our experience of mind, when there is a sudden glimpse of awareness openness, absence of self, then a suspicion arise: "Suppose I find that there is no solid me? That possibility scares me. I don't want to go into that. That abstract paranoia, the discomfort that something may be wrong, is the source of karmic chain reactions. It is the fear of ultimate confusion and despair. The fear of the absence of the self, of the egoless state, is a constant threat to us. "Suppose it is true, what then? I am afraid to look." We want to maintain some solidity but the only material available with which to work is space, the absence of ego, so we try to solidify or freeze that experience of space. Ignorance in this case is not stupidity, but it is a kind of stubbornness. Suddenly we are bewildered by the discovery of selflessness and do not want to accept it; we want to hold on to something.
Then the next step is the attempt to find a way of occupying ourselves, diverting our attention from our aloneness. The karmic chain reaction begins. Karma is dependent upon the relativity of this and that--my existence and my projections--and karma is continually reborn as we continually try to busy ourselves. In other words, there is a fear of not being confirmed by our projections. One must constantly try to prove that one does exist by feeling one's projections as a solid thing. Feeling the solidity of something seemingly outside you reassures you that you are a solid entity as well. This is the second skandha, "feeling."
In the third stage, ego develops three strategies or impulses with which to relate to its projections: indifference, passion and aggression. These impulses are guided by perception. Perception, in this case, is the self-conscious feeling that you must officially report back to central headquarters what is happening in any given moment. Then you can manipulate each situation by organizing another strategy.
In the strategy of indifference, we numb any sensitive areas that we want to avoid, that we think might hurt us. We put on a suit of armor. The second strategy is passion--trying to grasp things and eat them up. It is a magnetizing process. Usually we do not grasp if we feel rich enough. But whenever there is a feeling of poverty, hunger, impotence, then we reach out, we extend our tentacles and attempt to hold onto something. Aggression, the third strategy, is also based on the experience of poverty, the feeling that you cannot survive and therefore must ward off anything that threatens your property or food. Moreover, the more aware you are of the possibilities of being threatened, the more desperate your reaction becomes. You try to run faster and faster in order to find a way of feeding or defending yourself. This speeding about is a form of aggression. Aggression, passion, indifference are part of the third skandha, "perception/impulse."
Ignorance, feeling, impulse and perception--all are instinctive processes. We operate a radar system which senses our territory. Yet we cannot establish ego properly without intellect, without the ability to conceptualize and name. Since we have so many things happening, we begin to categorize them, putting them into certain pigeon-holes, naming them. We make it official, so to speak. So "intellect" or "concept" is the next stage of ego, the fourth skandha, but even this is not quite enough. We need a very active and efficient mechanism to keep the instinctive and intellectual processes of ego coordinated. That is the last development of ego, the fifth skandha, "consciousness."
Consciousness consists of emotions and irregular thought patterns, all of which taken together form the different fantasy worlds with which we occupy ourselves. These fantasy worlds are referred to in the scriptures as the "six realms". The emotions are the highlights of ego, the generals of ego's army; subconscious thought, day-dreams and other thoughts connect one highlight to another. So thoughts form ego's army and are constantly in motion, constantly busy. Our thoughts are neurotic in the sense that they irregular, changing direction all the time and overlapping one another. We continually jump from one thought to the next, from spiritual thoughts to sexual fantasies to money matters to domestic thoughts and so on. The whole development of the five skandhas--ignorance/form, feeling, impulse/perception, concept and consciousness--is an attempt on our part to shield ourselves from the truth of our insubstantiality.
The practice of meditation is to see the transparency of this shield. But we cannot immediately start dealing with the basic ignorance itself; that would be like trying to push a wall down all at once. If we want to take this wall down, we must take it down brick by brick; we start with immediately available material, a stepping stone. So the practice of meditation starts with the emotions and thoughts, particularly with the thought process.