For this point must above all others be maintained by those who allow nothing to be unbegotten, i.e., unborn, save God the Father only. And we must be careful not to fall into the absurdities of those who picture to themselves certain emanations, so as to divide the divine nature into parts, and who divide God the Father as far as they can, since even to entertain the remotest suspicion of such a thing regarding an incorporeal being is not only the height of impiety, but a mark of the greatest folly, it being most remote from any intelligent conception that there should be any physical division of any incorporeal nature. Rather, therefore, as an act of the will proceeds from the understanding, and neither cuts off any part nor is separated or divided from it, so after some such fashion is the Father to be supposed as having begotten the Son, His own image; namely, so that, as He is Himself invisible by nature, He also begot an image that was invisible. (Book I, Chapter 2, Part 6)

I observe. I reflect on my observation. My reflecting may be momentary or extended.

I make a decision regarding my observation. I may be tentative or confident in my decision.

I take action in accordance with my decision. My action may be wholehearted or somewhat less.

Each of these - observing, deciding, and acting - are aspects of my particular character my specific will.

To an outsider or even to myself these individual aspects of will are indivisible.