Let's start with the nature of the "I" I'm saying is free.
I don't know about you, but I'm not a ghost of identity passing through the walls of my brain and body, wondering why my material manifestation does so many silly things. The "I" I feel I am is no more one unified process than my body is one unified process. My body is a rag-bag of inter-connected parts, each with its own function, each monitored, loosely controlled and crudely co-ordinated by the autonomic nervous system, and sometimes consciously, and with no guarantee that all of them will work well together. Since the brain is part of the body, this applies to the brain as well. I see, hear, taste, estimate what is about to happen in my world (do I have time to cross the road before that slower-moving car gets here?), judge the people and things in it ("ugh, what a Spring 2003 office block") and a dozen other things, all at the same time, in what used to be called a "stream of consciousness". The human brain is a motherboard with many special-purpose CPU's, only one of which is there to have that conversation in our heads we call "consciousness". All the real work is done in the background, as it should be. The flaw in the traditional way of thinking about ourseleves and our identities, and hence of the nature of our freedom, is to suppose that we are in some way One, that there is one process - a soul, mind, spirit - that "is" us. We are a bundle of processes, many of which can communicate with each other but might not on occasion.
One of those processes has priority over the others, when it is engaged. This is the process which chooses the other processes get to use my body and the other resources I have. Sometimes that choice is made on a whim, or out of habit, or under the spell of a strong emotion - wisdom literature and guru books, and every book about being an effective manager, stress keeping the decision-making process conscious: do nothing without considering its effects, and do nothing in the heat of the moment. Some people do this better than others, I do it badly, and for most people, you can see the wheels turning when they try. That process is where freedom lives: it is the part of "I" which chooses and decides.
When I choose or decide I am influenced by what I have learned, experiences I may or may not have mis-interpreted, by what I have seen, heard, tasted and felt, by rumours, facts and thousand-year-old ideas, and my thinking is flawed, messy, incomplete, as deductively fallacious as valid and full of leaps and non sequiters. I limit my choices to what is possible, affordable, legal and acceptable, and that perhaps of all the choices, none are what I would do if I had the money, nerve and courage. Some of the thinking is conscious - feels like a conversation in my head, like reading without moving my lips - and some of it, perhaps the bulk of it, goes on silently. Just because I can't hear it doesn't mean it isn't happening, and it doesn't mean it isn't me who is doing it. The idea that thinking must be conscious or it is not thinking is a silly prejudice. I don't know about you, but I need as much thinking as possible to be going on silently, so I can concentrate on listening to music, or gazing at a blue sky. I want to know I will figure out the solution to a work problem without it interrupting my enjoyment of the present moment.
These influences are not constraints, just as reasons are not restraints and faulty reasoning is not a symptom of being human. These influences are, in fact, part of me. I am defined in part by my education, my experiences, what I heard from my parents, at school, on the radio and television, what I read, what I taught myself. Part of "who I am" is someone who can understand a proof in mathematics, identify the major 1950's jazz musicians after one chorus, and absolutely refuses to take part in fancy dress parties. It makes sense to say that "I" make a decision before I become conscious of having done so - actually, I thought everyone did that, it's how you know it's the right decision for you - but it makes no sense to say that the decision is not therefore my decision, as if only what I do consciously is "me". We are what we do, and what we intend to do, and we are the the gap between the two as well.
Reasons, arguments, influences and reasoning are important. It's not a decision unless there are reasons. If there are no reasons, it's an impulse, or a whim, and if being free isn't one thing, it's being at the mercy of every whim that passes through our pretty little heads. An adult may have all sorts of odd ideas flitting through her head, but she decides which one she will act on, if only by rolling a dice, and then deciding to abide by the dice's "decision". (The Dice Man decides to follow the dice, and part of that story is just how much self-control and will it takes to do so. Random living can be as demanding as routine living.)
(One reason that neuroscience seems so determinism-friendly is that it only looks at, as it must, toy decisions made in falsely simple circumstances. It doesn't look at the long decision-making processes of businessmen, or jurors, or me when my mobile phone contract is coming to an end. In these processes there may actually not be a point where anyone "decides" to do a particular thing, rather there is a drift towards the eventual choice as one by one the alternatives are eliminated for cause. Long-process decisions may include short-process decisions but are not resolvable into a series of them.)
So where's the freedom? You're staring at it: it's right in front of you. Papa Hegel said it, in his Aethestics. Freedom arises because my consciousness stops paying attention to the outside world and looks inwards at itself. (I had to read it over a number of times to make sure I hadn't been dreaming or misunderstood. Is it that simple?) Only the external physical world, including the people in it, can compel and constrain, so when I turn my back on it, I become free - even if I can't put my decision into action for fear of the Secret Police or for sheer lack of energy and money.
I'm free when I stop trying to do what you want me to do. This doesn't mean I act selfishly, become self-centered and ignore the rules and the needs of other people, it means I don't have a knee-jerk reaction to satisfy your every whim and demand. It means I "stop and think". Learning to stop and think, to not do as we're told or as we think others expect, to ignore our first impulse, and decide for ourselves, is part of becoming an adult. The teenager who doesn't "feel" as if they are free is quite right: they haven't achieved these disciplines yet.
The beauty of this is that it doesn't matter how I do it, or what does it, or even if I'm aware of much of it. It doesn't matter how you got your ideas of why I should do, or how I wound up thinking that what you think I should is so darn important. What matters is that I stopped responding to your priorities, and started responding to mine. The hardware and software I use to do it doesn't matter. It's that I do it that matters, not how I do it or which exact part of my anatomy passed what chemicals and electrical impulses to what other parts. In programming, we call that last bit "implementation" and everyone knows there are a hundred ways of getting the same result from the same inputs.
Freedom is not, in other words, a relationship I have with the Universe, but one I have with other people. I am not free because somehow I can dodge an hypothesised universal Laplacian causality with some Heisenbergian indeterminacy, nor because I can shake off all my schooling and indoctrination and choose freely. I am free because I briefly ignore everyone else and make up my mind to do what I want, which may or may not suit you, depending on how suiting you suits me. My guess is that there are many people who are so caught up in the race for power and influence, or the search for love and reassurance, or so bound up in their relationships with others, or in the endless reflecting mirrors of second-guessing and people-pleasing, that they really do not experience themselves as choosing, and whose consciousness has yet to turn away from the world, look inside itself and summon the courage to say their first "YES" to themselves.