[ajuc]

> We're just in a movie and one of the character says "What if we don't have free will? Maybe that'll change the end of the movie." No it won't, it's already set in stone, just fast-forward a bit.

That's mixing in-universe time (and change), and out-of-universe time (and change).

For characters in the movie stuff changes. One of them was alive and then died. It's objectively a change in state of that universe.

For us looking from outside the story is constant, so nothing really changes.

So, returning to the subject - beliefs of people in predetermined universe can have measurable effects in that universe, so they influence stuff. The way they influence stuff is predetermined, but so what?

If the beliefs were different (for example because of different inital conditions), then the universe would be and develop differently. That's enough IMHO to say that beliefs influence stuff in that universe.

[simias]

I see what you mean but in the absence of free will "beliefs" changing are just yet an other event steering your course. It's like a rock tumbling down a mountain and changing path as it hits a tree, sure the tree changed the course of the rock and therefore influenced the state of the universe by existing at this location at this given moment but that doesn't really get us anywhere. If you can't choose to believe in something then the whole concept of belief is just yet an other consequence of external stimuli and the chemical and physical reactions in your brain. You deciding to believe something is no different than you getting a flat tire and getting late to work. It's happening to you, not by you.

As far as I can tell the only way for free will to exist is if consciousness somehow transcends the physical existence and is more than a series of physical reactions. An other poster mentioned randomness but that doesn't really help, if there are absolutely random events occurring in the universe (for instance at the quantum scale) that means that the universe is effectively unpredictable but that doesn't grant us free will. Free will requires unpredictability but it must be the consequence of the conscious choice, not God rolling the dice while playing DnD.

[ajuc]

> As far as I can tell the only way for free will to exist is if consciousness somehow transcends the physical existence and is more than a series of physical reactions

Yep, that's why I don't think there is a free will. Removing it from the model simplifies everything and doesn't change any predictions.