However, from a 4-dimensional perspective, there is no time and no beginning or end. Everything is seen all at once: past, present, and future are known all at once. So where is free will? How can you change the future if it is already in the picture?
I never understand this argument.
I've said this before but if I offer you the choice of two activities, one you hate doing and one you really enjoy, you're going to choose the one you enjoy.
If I know your preferences well enough I might know what you're going to choose, but I'm still giving you the same choice.
The only difference is my knowledge, nothing else about your experience of the choice changes. You are free to choose whichever you wish.
Let's say you're watching a sports event live on TV and I am watching it on an internet stream which is delayed from the TV broadcast by a minute.
You know ahead of me what is going to happen but unless you tell me my experience of watching the event is exactly the same as yours.
Your foreknowledge of what I'm about to see in no way changes what I see or how I react to it.
The argument, although fun to think about, is flawed in the sense that there is no way to prove any of it. Does the 4th dimension exist? I think it does, but that is my personal belief.
Here is a thought exercise:
Let's say you have two choices, pizza or spaghetti.
At this particular cross-road, you have a decision to make - "what will I eat?"
Suppose I choose pizza (because who wouldn't?!), and now I have gone down the pizza road. The choice was made, however, since I can never go back in time to re-evaluate that choice (at that time), did I really have a choice? Was eating spaghetti (at that junction) ever REALLY a choice? How can you say it was a choice? Regardless how many 'branches' there are on the road, you can ultimately only go down one road. So, philosophically, you will never know if you ACTUALLY had the choice, or if the choice had you.
That is another way to look at it.....
Suppose it is not us who makes the choice, but rather the choice that makes us? Maybe each pathway chooses us, rather than we choosing the pathway? Again, how can you prove or disprove such a thing?