By doubt I mean an experience of uncertainty in a situation. — MoK
I went back to your definition in the OP, and based on that, of course, I have doubts. Right now, for example: Should I respond to your post and have my name appear two or three times on the homepage? Some people already say I post too often.
What I do next is become still, stopping my thoughts. (Since you're interested in free will, my choice to become still is a learned behavior—I’ve learned that thinking doesn’t resolve these questions.) In this case, an answer comes to me quickly and clearly: yes, I should post this response. Only after that does the reasoning behind it come to me. It works like a logical process, but in reverse.
Then, of course, your question is: where does that first 'yes' come from? Is there such a thing as a free mind?
I believe even a deterministic system can have 'free will', at least in some sense. This is because our conceptual understanding of deterministic systems is limited. A deterministic system as complex as the brain can be understood at the component level (neurons in this case), but the emergent behavior that arises operates on a different level of understanding, with no direct logical connection between the two. Yes, the connection exists, but conceptually, we can’t fully grasp it. It’s where we have to say 'stop' to conceptual thinking, much like division by zero is not allowed in math.
So, an answer comes, and I don’t know from where. Is it a free mind? Concepts play tricks on us here. For instance, is it possible to choose the opposite of what you actually chose? If not, how can it be free will? I don’t let those concepts fool me—that’s how I deal with it.
Finally, to clarify why I said I don’t have doubts: for me, doubt comes with a feeling of unease. In what I just described, I didn’t feel uneasy, so personally, I wouldn’t call it doubt