I do. I won't go into a whole bunch of detail here, but, there have been plenty of tests done that show someone can predict what the next answer you're going to give to a yes or no question is up to 6-7 seconds before you even make the decision. It's because your subconscious makes the decision before you actually act out the decision, and brain scanning and things like FMRI show the parts of your brain that activate when making a decision. Well, if we truly had free will, couldn't someone look at your brain and make a prediction, and then to counter it, you could simply choose to do something else that is unpredictable? Well, it's still predictable with close to 100% accuracy. This would suggest that our unconscious mind is what is reflected by our actions, and therefore free will does not exist as something that we can wield on our own.
Other studies suggest that our subconscious acts based on how we truly want to do things. This would suggest that even though we are predictable, and we don't always consciously make decisions, that we still inherently have free will, since the very essence of what makes out our decisions before we even act them out, works perfectly according to our own wishes/what we really want to do. This is a powerful argument FOR the attribute of free will because our subconscious mind is heavily linked to our conscious mind. Obviously to see this argument in it's full beauty, one must have conceptual clarity on what exactly is defined as the subconscious/unconscious/mind. However, the main argument here, is that despite being predictable, the link between the different aspects of our mind/brain allow us to do things the way we wish to do them. I personally believe in this, and I think that it is a very strong argument for why we have /do/ free will.
I would concede that it is also possible that our "mind" could be something else. Perhaps a soul exists. And if it does, maybe the soul plays a part in all of this. I know that there are people who argue that our bodies are just vehicles, and our souls are the things that are truly alive. That would suggest that our souls are possibly what has the ability to make decisions and have free will, and perhaps the brain activities shown on FMRIs is something that happens when *we* or our when our *soul* makes a decision. The body is just a vehicle, and the soul is actually what we are, and out bodies act based on decisions that our soul makes, assuming that We are Our souls. I think that that may be a possibility, too. I'm more of a person that likes facts that I can actually see, so I tend to believe in free will because our subconscious mind (whatever the "subconscious mind" really is), is what makes decisions, but makes them so based on how we truly feel and based on an outcome that we truly want. There's some pretty good evidence that our subconscious acts according to our own desires, which is why I think that even if we don't consciously make certain decisions, they are still a part of the bigger picture called free will, which I also believe that we possess, since we can choose to change/have different desires.
I also tend to think mathematically and computationally. I believe that we are machines in a sense, and they we are operators. I believe in our lives and our bodies; that those two things are just compilers/interpreters, and there is something more that we can't see, which is our true selves. I believe that that which we cannot see (our true selves) is what truly makes our decisions in life, with absolute free will. And I believe that our bodies give us tempting evidence of lack of free will simply because they are compilers, and we don't have technology that is sophisticated enough to detect, and map out that which is our true selves. An FMRI sees brain activity, not soul (which I believe we have) activity, and therefore only sees the input/output that our compilers are able to give in a more tangible form.
With all this in mind, we still don't fully understand how even the basic human brain works, and I don't think we will, even 50 years from now. I don't think we have all of the information we need to truly even determine the existence of free will, or at least how the latter plays a role in our brains. The whole free-will problem is still in a grey area, in my honest opinion, for this very reason. We can extrapolate with a certain degree of accuracy, but with how little we know about the brain (depending on how you look at it) I personally don't think it's possible to determine whether or not free will is even an actively existing thing, or whether it's simply a construct that humankind has created because they don't understand what compels them to act in certain ways.
I think that it's also worth mentioning all the external stimuli in the world that has noticeable influences on a lot of the everyday decisions that we make. Are we inevitably forced to make certain decisions (I don't know, maybe, natural instincts/other innate behavior? Parasympathetic [self-regulating] processes?) or can we simply make the decision to turn those things "off" despite them being systematic and passive? Or perhaps, are these things just biological brute facts, and therefore negligible when discussing the problem of free will? Does free will focus only on voluntary actions, or does free will also play a role in all of the involuntary actions that happen inside our bodies?
Another interesting theory, I think, is that there is substantial evidence that shows patterns. For example, free will may not exist at all because everything we do, has to have been done. It had to be that way because circumstances made things so that doing this certain thing is the only that that even /could/ have happened. Did you eat something today? What did you eat? Has everything that you've done in the past 24 hours affected you such that whatever you ate today was already predetermined? Could you have just as easily started eating something completely different? If you could have, how do you know that you made the decision that pick up a different food and eat it? Maybe circumstances are as such that you were influenced by an external whatever so that you chose to eat whatever it is that you ate. I mean, think about it. Why did you eat whatever it is that you ate today (I hope you did eat something today, lol)? Why did you eat it? Did you ever eat it in the past? Did you eat it again today, not because of free will, but because you tend to eat things that you like, and you liked what you ate, and so you were bound to eat it again?
I often think about that specific thing a lot. Every (or not, but close to every) time that I make a decision, I often wonder how things would have played out of I did something different, or if I could have just as easily done something completely random.
When determining free will, "random" is also a term that needs a lot of conceptual clarity. A lot of mathematicians (which sometimes I feel like I appeal to) will tell you that anything random is really just "pseudorandom;" that nothing is truly random, because everything, even something that is made to scramble numbers, has some kind of sequence that it follows. So even though I do believe in free will, I often ask myself is it possible that I'm wrong, and free will doesn't really exist? Because nature has a sequence, everything seems to happen for a reason. Every effect, from what most of the universe and I have observed, has a preceding cause. Would something still be considered free will if something that has proceeded it has a direct relationship to it, and therefore makes an outcome expected? Is it possible that /not/ every effect has a proceeding cause (an "uncaused caused")? What would such an uncaused cause be?
Back to what I believe as far as free will go. I believe that there is an uncaused cause. And I believe that that is our soul. And yes, by extention, I believe that our souls are immortal, which is why it is possible for them to be this uncaused cause. I believe the soul to be necessary. I believe that our bodies are contingent, but we (in our truest forms) are necessary beings, and have the power to make our own decisions. Though we are restricted and bound by physical laws, and therefore can't necessarily do /anything/ that we want, out of all the options that we do have, I think that being necessary beings gives us the power utilize the understanding that we have (or at least that I have) come to describe as free will.
I would have to say that I'm on the fence at this point in my life between having hard and soft deterministic philosophy. I am a logical person, a mathematical person, so in some aspects, I definitely have a hard deterministic background. Despite what I just said, I would say that I still have more soft deterministic beliefs since regardless of any laws regarding causality, I believe that there is something more to us which inherently gives us the ability to exercise free will.
Feel free to poke holes in my arguments. I don't have a single argument that is undeniably perfect. I'm sure there are tons of holes to pick at in any of the arguments I've given. Any feedback would be great as well.