A lot of theologians, philosophers, and thinkers have argued about the nature of the human will. The bible depicts the human will as being free in that it chooses what it pleases.
Many forms of freedom wish to define freedom as the "ability to do other wise" so that the will may act in any direction at any moment.
It is an interesting philosophical definition but it doesn't have a consistent view of person-hood or a biblical basis. The bible defines freedom as doing what one pleases.
In the deepest sense we are most free when we follow God. That is true freedom when our will matches God.
Those in sin are free none the less. Their will is aligned against God and they are doing what they please in this regard.