This article has some interesting points about the way the mind is structured, although I might tweak some of the wording around myself. But I just wanted to capture what they have.

Basically, they are saying that the majority of psychological models posit the ego as the one central ruling structure of the mind. They are here saying that there are in fact two. And that the other one has something to do with the subconscious mind, and the subconscious is what causes the ego to be constructed in the first place.

Though there is a wide variety of existing models of the human personality in psychotherapy today, they all have one thing in common. They all contain only one center to the personality — the entity called the ego with its intellect, and the intellect’s powers of perception and cognition. This ego also contains a will, which expresses itself as willpower.

In our model, the ego with its intellect and will are also recognized as a distinct center of the personality, but it is only one center of the personality, and not the most powerful center at that.

In our model, there is another distinct center of the personality — another ego, another intellect and another will.

Not only is there a second center to the personality with its own intellect and will, but the intelligence and willpower in this other center of the personality are vastly more intelligent and more powerful than the limited intellect and will of the ego center of the personality.

In fact, this second center is not only more intelligent and move powerful, it pre-exists the ego center chronologically as well.
In addition, it is this second center with its superior intelligence and power that creates the ego, the ego’s intellect and will in the first place.

At the moment of birth there is no ego, intellect, or will present in a newborn baby. They are formed in the baby much later. However, as you will soon see, this other center has been present since conception, and is what causes the ego personality to gradually be formed.

Personally, I’m more inclined to follow the archetypal psychologists like James Hillman, and say that there are in fact numerous centers of control in the mind - many small ego-like entities (autonomous complexes) - all specializing in different subsets of functionality, and all working together to create a complex flexible mind. A polytheistic (or you might even say democratic) mind.

But anyway, I also think this point that they make about Freud is fairly good:

The result of this basic belief, is that only those things which belong to the ego and the intellect are good, pure, and valuable. Everything that comes from within, from this subconscious is dark, dangerous, and destructive.

I think this has everything to do with Christianity, first of all, which birthed the Enlightenment, and the Scientific Revolution.