One problem I've been working on (I get this from Gilbert Ryle) is just how do we produce speech (or thought)s in words)? In some sense we (ideally) know what we're going to say before we say it. But it can't be because we rehearse the words and then recite them. That would lead to an infinite regress, because we would ask how we produce the rehearsal and we would get a rehearsal of a rehearsal, and so forth.
(Of course, we do sometimes rehearse what we're going to say, as when we're going to ask for a raise or propose marriage, but we're still left with the problem of where those words came from.)
So the rehearsal theory is off the table. We could instead go with Sam Harris's theory that our choices and preferences - presumably including our choice of what to speak - come "out of the darkness," i.e. are the product of purely unconscious causes. I profoundly disagree with Harris's rejection of free will, and his description does not seem to match my own experience of speech-production. I am guessing that most people's experiences are somewhat similar to my own.
My own experience is that I am not rehearsing what I want to say but rather that I have a wordless "sense of meaning." It is a kind of feeling or a frame or colored lens around or over my situation. Knowing how to speak means that I know how to "translate" this feeling into words. It's a projection of my consciousness out into the world.
So where does this feeling come from? I don't think we're in danger of another infinite regress because we do not derive the feeling from another feeling (except in the case where one item follows another in a train of thought). I don't think it comes "out of the darkness" either. Unless we are troubled by intrusive thoughts or are having a flash of insight, the feeling just seems "to be me."
I am not sure where to go from here. My current hypothesis on the subject consists of two elements: 1. Our basic conceptual awareness isn't verbal but intuitive, at least at first. 2. The driver of the process is "directed attention." This is a specific form of what Ayn Rand referred to as "focus." It's our free will. We are the primary cause of our attention. It doesn't come out of the darkness. It's "me." Of course, our sense of things is derived from our context, including things which are unconscious, but it is still us.
Now for this hypothesis to stand up, I have to demonstrate that human beings have the kind of free will that Rand (and Nathaniel Branden) described, in which a human being is the first cause of their level of attention. I think they made a good start, but I at least believe there's more to be done. I'll look around and see whether someone has already done it, and if not, I'll have to do it myself!
In this mini-essay I have concentrated on speech production, but the same questions and hypotheses could apply to many kinds of intentional human action. I've got my work cut out for me.