There is the illusion that the ego is the big player in the psyche but it is just an illusion, as the unconscious is the very ground or base out of which consciousness emerges.
Perhaps we can say that a measure of free will exists as the ego can choose a subject to think on, meditate on or simply day dream or fantasize about. Sometimes the unconscious can be very over powering it depends on issues in the unconscious has but we are unconscious of or are only vaguely aware of. Intrusive thought are like this as well as things that have caught our attention and we just can’t seem to get our minds off of.
The formation of the “self” as a center organizing archetype of the human psyche may be the real big player and in far more control than the ego, there may be where a much greater degree of free will exists. But that is another subject about the “self” which one can do research on.
I wonder if Sam Harris (or maybe Brian Green) has any ideas about self since I think he study eastern spiritual practices and must be familiar with the subject.
Jung idea of the Self:
http://en.wikipedia.org/wiki/Self_(psychology)
Jungian understandings
Further information: Self (Jung)In Jungian theory, the Self is one of several archetypes. It signifies the coherent whole, unifying both the consciousness and unconscious mind of a person. The Self, according to Jung, is realized as the product of individuation, which is defined as the process of integrating one's personality. For Jung, the self is symbolized by the circle (especially when divided into four quadrants), the square, or the mandala. The Wise Old Woman/Man can also serve as 'a symbolic personification of the Self'. [26]
What distinguishes Jungian psychology from previous iterations is the idea that there are two centers of the personality. The ego is the center of conscious identity, whereas the Self is the center of the total personality—including consciousness, the unconscious, and the ego. The Self is both the whole and the center. While the ego is a self-contained little circle off the center contained within the whole, the Self can be understood as the greater circle.
The Self besides being the centre of the psyche is also autonomous, meaning that it exists outside of time and space. Jung also called the Self an imago dei. The Self is the source of dreams and often appears as an authority figure in dreams with the ability to perceive the future or guide one in the present.