[simias]

>An individual believing it has free will, will certainly act different to an individual that believes all actions are predetermined

Sure, but then you still have this loop the parent talks about: if there's no free will then the insight that you have it or not is also completely predetermined. This discussion is predetermined. The reply that you may or may not write to this comment is predetermined. 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.

[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.

[nailuj]

Not necessarily, there could still be effects of true randomness that are not influenced by previous causes.

[simias]

That doesn't really give us free will, otherwise the NPCs in videogames would have free will (since they experience and react to events in-universe which are effectively absolutely unpredictable since they come from outside the universe).

Maybe the universe is a simulation and the randomness we observe when we look at quantum fluctuations comes from /dev/urandom in God's computer. That doesn't really get us anywhere when it comes to the nature of consciousness and free will.

[coldtea]

True randomness is also beyond the control of the individual so it's not a "will".