This is far too vague, js. How is it key? The future is amorphous, ambiguous, undefined and immensely complex in its possibilities. What test does it give us?
I plead guilty to much of this, but only in degree, not in principle.
If you think for a moment about classical physics, the key concept was cause and effect, and cause always preceded effect. Living things turn this on its head. The behavior of living things is determined by the anticipated consequences. Reflexes and tropisms are generally analyzed as belonging to the classical view of cause and effect, but when you get to brains -- particularly brains with a significant sized temporal lobe -- you get more complex kinds of anticipation. This is the realm of psychology, admittedly a fuzzy science.
When you say "the future is amorphous, ambiguous, undefined and immensely complex" you are saying it is unpredictable in detail. But it is not entirely unpredictable. Every living thing must anticipate future events and consequences or die. Plants must anticapate seasonal changes, animals must find food and water. Animal species with simple, reflexive, brains place very little value on the individual life. As you work your way up the scale of brain size, there is more importance attached to the survival of the individual, and more means to enable this survival.
If you think about your personal life and what it means to have free will, I believe you will say you have the ability to make choices. But what does this mean? For me it means analyzing the current situation in terms of things that are possible to do and the anticipated consequences. There are lots of interesting things about this analysis, starting with the fact that there is no "list" of possible things to do. The list would have to be infinite and include things that have never been done before by myself or anyone else. Consider Star Trek's Captain Kirk's solution to the unsolvable training exercise -- cheat.
Secondly, the list of anticipated consequences is also infinite and unknowable. When you feel yourself engaging in free will you are feeling yourself solving an unsolvable problem, predicting the future.
The upshot, I would suggest, is that we consider ourselves rational beings. That's because we forget that Great Library in the Sky, wherein is catalogued all those things a guy does to win and keep a woman. I introduce this hypothetical guy, this rational being, to that library, occupying a full city block, comparable to Powell's Book Store in Portland, OR, and wait patiently on the curb, smoking my cigarette, while he has a quick look. Meanwhile he is all the while wondering "How can a library be 10 stories tall?". When he comes out wide-eyed I say "Now, tell me about the Universe, Mr. Rational."
Living things turn this on its head.
Yes, they do.
But [the future] is not entirely unpredictable ... If you think about your personal life and what it means to have free will, I believe you will say you have the ability to make choices. But what does this mean? For me it means analyzing the current situation in terms of things that are possible to do and the anticipated consequences.
I'm suggesting that more than rational analysis goes into the process. Many "life decisions" (if you will) are based upon anything but perfect information. I have discovered, though, that there is a still, small voice within that sometimes says to me "It would probably be better if you did not do this." When I was younger, sometimes I would and sometimes I wouldn't. If I ignored this small voice (a "gut feeling" really), I would often or always regret having taken the warned against action. I don't understand it, to say the least, but I'm clear that it has nothing to do with rationality.
... [T]he list of anticipated consequences is also infinite and unknowable. When you feel yourself engaging in free will you are feeling yourself solving an unsolvable problem, predicting the future.
It's possible that you may instead be creating the future.