The thoughts in our mind come and go... we can't stop them, we can't will them. Think about this: can we stop how we feel? When we are feeling sad, can we stop the sadness instantaneously? The answer is an obvious NO...well at least most people can't.
Our 'sense of self'... gives us a sense of personal decision-making and action-taking ability...
The 'sense of self' seems to be in charge of these actions and decision-making... but is this really the case?
The ego and personality has no personal free-will. The sense of self is caused by the impression of continuity and connectivity of thoughts that gives the impression of coherence and personal-willing. In another word, the sense of self IS the sequence of thoughts itself... that is interspersed with the intelligence that make coherent meaning of this sequence of thoughts. Why? Because thoughts are energy.
This can be realized within deep meditation, when the rising of these thoughts are clearly perceived. In such meditation, one will discover that there really is NO observer of these thoughts. The subsequent thoughts that arise after the previous thought are the 'observation' of their predecessors. All these are happening at lightning-fast rate, and therefore is perceptible only under deep clarity.
Only the soul, oversoul or source has free-will, because it is the state that held the impulses and intentions, desires and purpose for the incarnated personality. But, ironically, part of the soul, oversoul and source itself may not have a 'sense of self'.
Sense of self, the ego and personality are only a part of the entire field of consciousness. The 'sense of self' is not the doer, it is part of the 'being done'. However, this realization does not imply that all in existence is fixed and static. In fact, the opposite is true. The visible (our conscious self and personality) works in partnership with the formless or the invisible. It does so in order to realize the potentials into physical manifestations. All of physical manifestation that is perceptible are in fact already 'being accomplished.'
Enjoy THAT mind-twister ;)