There's a pretty good essay from Scott Aaronson [1] that tries to disentangle the question of randomness from unpredictability, by saying that unpredictable events (which he says are the only things we know of physically that might permit something like free will) are events to which we can't assign a probability distribution.

It separates out the notions of "random" events like coin flips, which we know will go heads with p=.5 and tails with p=.5, from truly unpredictable events, where we can't say even in principle what the probabilities of the outcomes might be. These latter events are where he finds some wiggle room for free will.

[1] http://www.scottaaronson.com/papers/giqtm3.pdf

That's a good point, I'm not quite sure how to answer that. I know almost nothing of quantum mechanics. My logic is simply that if you had a large enough calculator and nothing was truly random that you could predict us having this conversation from the moment of the big bang. That's incompatible with true freedom of will (which someone is sure to ask me to define, I swear metaphysics suffers from death by definitions). But given true randomness:

1) Person faced with ethical decision

2) Random events somewhere in the brain

3) _____________

4) Unpredictable autonomous decision!

Or something like that.

Edit: moyix's is a much better response than mine

>I'm not sure random will is equivalent to free will. It's not per se, but it's kind of an analogue -- in that both are escapes from determinism.

Something random can be seen as an event that has no causual expanation (and thus cannot be predicted by studying the previous state of the system). But there still must be an agent, bringing the random outcome into the universe. In the same manner, free will too can be thought of as a event that has no causual explanation.

In this case, the difficult question is how a "free will" based decision relates to the person making it (if it's a product of his memories then it's deterministic, and thus not free).

One way to solve this might be to think of the persons' decision making process as a "random number generator". So, the output is deterministic (the same for the same state of memories, like with a programmatic RNG), but with a unique seed for this person (the state of memories itself), and a unique RNG algorithm (the wiring of his brain).

In this case, unlike calculating a dice result given dimensions, weight, power of throw, wind conditions, etc, nothing can produce the same output as the free will person without going through the whole process (a total simulation).

True randomness eliminates determinism. With determinism free will is ruled out. That doesn't mean everything that shows true randomness has free will.

> With determinism free will is ruled out.

This is a popular statement but I've never thought that to be the case. Imagine you're creating a movie. You can pick the actors, the characters, the plot, etc. When you play the movie, the playback is completely deterministic. But that doesn't mean free will didn't design the film.

I could see something similar applying to reality. Your actions may be predetermined, but that doesn't specify exactly how they were determined.

> With determinism free will is ruled out.

Not according to compatabilism.