Jean-Jacques Rousseau
Man is not free and he would never be. If free will really exists, limits and boundaries would have not existed. The presence of the other causes the other’s non-existence. We aren’t born with the knowledge of the world; we only learn a small portion that our community accepts, but no one seems to realize that. We are not free because we have built constructs to ensure our survival as a race. In order to evolve and pesist, humans have built these constructs to make sure that there would always be a next generation. Society, culture, government, in all their variety of forms are, constructs that limit freedom while simultaneously providing avenues for productive growth of the population. Some to a greater or lesser degree than others. Though these constructs limit us to exercise our freedom, they are the primal factors for organization of matter in all sense. Without restrictions, everything would be confusion and chaos.
From a societal point of view, there's supposedly the freedom of speech and the like, but constantly we are reminded of the pressures that could well be applied upon us; whether by law, punishment, negative attention of any sorts, etc. with which we often form "internal" and "external" barriers to prevent certain actions - thus taking away the free will. So at best really the concept of being free in the society we reside in is extremely limited. Sure, you could kill someone, but others will ultimately aim to force their own "free will" and take yours away. So does it really exist?
No. It does not exist and in all way, that is good – otherwise crimes would be rampant, and there would be disorder, more wars and deaths, more sins, and humanity would be unimaginably bad. Such is the way of nature and the world. And will we enjoy great happiness if we have complete freedom? I don't think so, it doesn't work that way, as far as history has told us.