CrystalShadow said:
But specifically, 'Free will' in a 'deterministic universe' is by definition a logical paradox.
Not necessarily, as I am talking about deterministic events in the universe, not the universe itself being set. A deterministic event would be: given the exact same set of circumstances, everything would progress the same way. So, for example, if I flipped a coin on the 20th of January 2015 at 10:16:41 and it came up as tails, any time I repeat that exact coin throw, it would come up as tails. It's a very naive example, I know, but it's just to illustrate the point that the
event is deterministic. Of course, if at that point in time I had bet that the outcome would be heads, then I would also always bet on heads, thus losing the bet every time.
Unless the initial parameters shift, in which case, so if I were made to throw the coin a little higher or something and it may come up as heads thus making me win the bet.
I'll actually use a second example as it's much better and it much better illustrates what is it for the events to be deterministic. It's even much better fitting for this forum, as I'm going to use games: pick any game with a RNG sequencer persistence between save states and you're done. The first example that comes to mind is XCOM: Enemy Unknown [footnote]make sure that the "Save scumming" option is disabled - if turned on, it reseeds the pRNG on load. Also, make sure you're not playing Ironman mode, so you can "go back in time" by loading[/footnote] and Heroes 3[footnote]something that was actually changed in WoG, I believe, but in the base game (+expansions, I think), the random sequence is predetermined even after loading[/footnote], so let's take XCOM - if you're on a mission the sequence that the pRNG produces cannot be changed. Here is an example
1. You have 99% chance to hit
2. You save just before you take the shot
3. You take the shot
4. You happen to miss
Now, any time you reload do step 3., you would ALWAYS end up on step 4. No amount of game loads would make your soldier hit. This is true AS LONG AS you keep doing that, as you would always be fed the exact same result from the pRNG, thus making this action entirely deterministic. However, if you ever do something different, the starting conditions are now different - if you took a shot with a different soldier, the sequence has now moved along, thus if you retry the shot now, you most likely would succeed. You would, succeed deterministically, as no amount of reloads would make you miss. No amount of reloads would make you have a critical shot, either, provided you didn't get one. Since the sequence is "known"[footnote]not to us but if anybody was bored enough and felt like it, they can map it out[/footnote] every action throughout the mission is predetermined and if you replay the mission using the EXACT SAME steps you took before, the outcome would be EXACTLY the same.
Thus this is a really good simulation of a universe where the events are deterministic. You would find out that even the AI would respond in the exact same way given the exact same circumstances, simulating what would people do in this universe. However, the AI is not robbed of decision making. Sure, that's not me calling the AI having "free will" but for the purposes of our little universe simulation, it is close enough. So, let's say you did one mission and your soldier called...dunno, Chuck Norris, for example, was never once attacked during the mission, yet everybody else had their asses handed to them. You decide to replay the mission and knowing Chuck Norris was never attacked, you rush him over straight into the middle of a room full of aliens. What would happen now is you would have one less Chuck Norris on your team.
So this is an illustration of why exactly free will doesn't clash with determinism. You've changed the parameters, you now get a different outcome. A completely predictable outcome - more than "I told you you shouldn't do that", it's an absolutely repeatable experiment yielding the exact same results any time it's reran with the same input. Change the input, that changes the outcome but, again, you can repeat with the changed input and get the same (changed) outcome.
With this in mind, it's entirely reasonable that somebody can bork the timeline. They could examine it, see how it works, find out it works in this fashion, then go back and kill their grandfather. Let's call this theoretical person "Pandora" after...well, you know, that Pandora. So, to come back to 12 Monkeys, Pandora can be somewhere further in the future and she could look through the events, then try to stop Bruce Willis from going back in time. Pandora's free will is not impacted - they can make that decision, given the right set of parameters.
There is nothing in the universe to prevent Pandora from doing so - hence free will. Yes, you can claim it's a similarly predictable outcome to the XCOM scenario and if you feed people the same things, they would produce the same behaviour[footnote]yet, that's pretty much already a thing - social engineers, for example, exploit it to a great degree.[/footnote] however, they are free, as in, the range of output their thought process produces
is unbound.
I can use XCOM again as an example of decisions NOT being unbound because 1. I already talked at some length about XCOM and 2. it's to show that XCOM was just an example to illustrate how a deterministic events would behave, not the whole thing[footnote]because this is the Escapist and people are really fond of pointing out how an example doesn't have 1:1 mapping with reality...when really it's pedanticity to such a level I tend to either not use them or make sure I clarify that IT'S NOT SUPPOSED TO MAP 1:1 WITH REALITY[/footnote]: it's simple really, no matter how much you play, no matter how much you replay, the aliens would never surrender. Nor would Exalt members. Civillians would never pick up weapons and fight (not during the mission, anyway). All these entities are entirely incapable of doing those actions. Thus a universe without free will would could make some logical conclusions impossible - nobody would ever be able to decide to cause a paradox, ever, for example, no matter how you tweak the circumstances. One extreme end of no free will can be people literally unable to change their minds about anything - one example is the Discworld novel Mort, where, in short, for...well, reasons, one person who was supposed to die, didn't actually die. This however, clashed with how history works[footnote]or "works", if you will. History/fate/destiny in the Discworld is, erm, not really exact. History in particular is more of a patchwork of histories crudely brought together.[/footnote] and everybody else in the world continued acting as if that person had died.