This is certainly a loaded question, and one that extremely subject to opinion. When creating a thesis in this regard, you will need to specify the exact type of "freedom" that you intend on discussing. This could be the concept of "free will" as a human being, or the concept of freedom as an individual in a democratic society.
Because of the way that your question is worded, this response will be operating under the assumption that the subject is individual freedom.
As an absolute concept, personal freedom is an illusion because we make small concessions of freedom in order to create order within a society.
A few points that you could use to deny the concept of absolute freedom are as follows.
- Complete personal freedom to do anything may infringe upon another individual's freedom to be free of harm.
- In order for society to function, personal freedom must end when the actions of an individual begin to have an adverse effect on another.
- Laws are the methods by which we mediate between personal desire and community, and (ideally) represent communal values.
- While we would not need laws in a world where everyone shared the same values, there will always be certain aberrant behaviors for which certain moral standards must be legislated.
- Even in the hands of responsible and well meaning citizens, certain actions must be prohibited because the law needs to be clear and rigid in order to be functional.
- With all of this in mind, it is necessary to sacrifice certain and extreme personal freedoms in order to create a system of order that benefits all.