Some decisions or impulses seem somewhat out of our control. For example, I began to write songs in September of this year. This arose from simply staying at my girlfriend's house for a few weeks to take care of dog and chickens while she was in Japan, and fooling around on the piano. Soon, I had a song, then another one. Then I began writing the lyrics for them, naturally enough.
This is still voluntary, in the sense that I wasn't forced to do it against my will. Rather, I felt as though I should listen to this impulse, that it was coming from somewhere significant that I would ignore to my detriment. It isn't a scholarly impulse per se, since I am not in the Songwriting Department, though I did develop a proposal for the discipline of song studies" at one point in the recent past.
It is also deliberative, in the sense that I take deliberate, self-conscious steps, to compose what I feel is a good song, and to educate myself enough to do. I have to write the next song without a tritone substitution or using III instead of I, and not beginning the song on II.
Perhaps the relation between the deliberative and the involuntary is similar to that between the routine and the improvisatory. In both cases, we can understand human creativity as mysterious in its workings. It requires both conscious and unconscious effort, and we don't really understand the relations between these two things.
Although I don't think much of Malcolm Gladwell, the 10,000 hour principle he popularized is useful. I'm thinking, for example, of spending 10,000 hours watching television, a seemingly passive activity, or listening to songs and singers in the tradition of the great American song-book for countless hours, as I have done. Many of us are intuitive experts on many things that we have done over and over. I know (in the sense of recognizing) hundreds of songs by Gershwin, Arlen, etc... My songs are likely to be amateurish, yet I feel that must teach myself to write them.