The key word in this definition of freedom is in the meaning of the word "want".
What is it that determines what you want to do?
Is it you, or is it pre existing unavoidable consequences to events?
..
From my own personal experience, and from simple logic, I am happy to acknowledge that my
wants arise for some or other reason. Were this not to be the case, then my wants would be random, and if humans, uniquely, had evolved a disposition to random behaviours, then we would not be here to discuss it. The choice I make between alternatives reflects the greatest
want out of the rivalry of competing wants. This is how brains resolve choice, something they do incessantly- we weigh options against each other on a scale of emotional value to identify the most appealing option.