Yes, sure, the future has been predetermined in a deterministic universe. But if no person in that universe can ever figure out what that future is going to be, is there any practical distinction?
Yes.
Yes there is.
Even if I don’t know the answer to an equation I can be reasonably sure that the equation will not change half way through working it out. To someone theoretically conscious in the middle of said equation, their ignorance of the outcome does not change the fact the outcome for them does not depend on their feeling about it.
To that ignorant internal observer there is no effective difference, but that’s worse in my opinion. Being delusional that you have a choice in anything you do despite any outside observer being able to tell you you don’t. This does not enable free will, this only causes the delusion of free will. One must imagine characters in a book would have this delusion, if they existed in some form.
Again in a deterministic universe we are akin to those book characters, not the author. No matter what happens we have not written the next page. We have had no influence on the next page. We are simply ignorant of that page until it is read by time, or rather until our limited ability to observe catches up with the next page. To us as those characters we wouldn’t know we don’t have free will, but this doesn’t mean it exists. It is written already regardless.
The other comments go over it more thoroughly but let’s more directly connect it to this idea; specifically this post is talking about Star Trek rules for teleportation.
This type of teleportation is that your body is scanned down to the exact spin of every quantum particle and wave, then it is destroyed entirely, and turned into energy by one machine. This information is encoded in a data stream that can be saved, stored, and reused at any point. Then. Somewhere else, a different machine reads that data, and fully recreates you down to the spin in the quantum particles making up the arbitrary concept of ‘you.’
In order for data to be stored or retrieved it has to be unchanging, predictable. If every time you opened your company’s spreadsheets they changed randomly one would assume something is terribly wrong somewhere in the system. This essentially means that by some method you are able to determine the exact ‘data’ involved at any give point.
When we extend this to ‘consciousness,’ we then have the natural consequence of these facts being that consciousness itself is determinable. That there is some set of predictable things that can be done to generate a person that believes they are conscious. If there is truly no difference between the person that was killed, and the person that was made, then the natural consequence of this is consciousness itself is deterministic, i.e. there is a set of predictable interactions that given infinite time and infinite resources you could compute.
If, then, there is a predictable set of interactions that can form consciousness; then like all other predictable interactions we would be able to trace its start, its source of these interactions to the start of the universe. Which would mean there is no possible variance of what could have happened. 1 + 1 will always equal 2. Every single time. We can derive that to mean a + b will always equal c. Which if true, would mean that given the exact starting point of all energy in the universe, we can perfectly predict, or recreate, the universe.
This has the logical consequence of meaning there is no other outcome than what has happened; and what will happen has already been determined. This isn’t just the generality of ‘fate’ or ‘destiny,’ this is down to every single specific micro interaction, including your thoughts.
In this world, should it exist, the fact you read this comment was determined at the start of the universe. Name a struggle ‘you’ overcame. You couldn’t have failed at it. You didn’t struggle. You were always going to do exactly whatever you did. You didn’t have a choice to fail. You didn’t have a choice, period. You didn’t achieve anything. You can’t achieve things, because achievement implies an alternative. You don’t have the luxury of alternatives in a deterministic universe. Everything will always play out exactly the same, no matter how many times the underlying equations of the universe are solved.
Consciousness being deterministic, as evidenced by being able to be perfectly copied and arbitrarily pasted, means that there is no choice involved in life. That no choices have ever been made. By anyone. At any time. And never will be. I didn’t choose to write this comment. You didn’t choose to read it. Your thoughts about it are not yours, just the result of an electrochemical reaction that is a small part of the equations that started this universe. You literally can’t choose to act on them and reply, whether or not you reply was decided for you before light as a concept happened to form in the universe.
Free will, as a concept, posits exactly one thing. That an individual entity with free will can choose something. That they are not being led along a predetermined track with no ability to simply stop and get off. This concept is entirely at odds with a deterministic universe, as no choice can be made once the universe ‘starts.’
So, in order for free will to exist, we cannot be in a fully deterministic universe, or at the very least consciousness and that which it affects has to be non-deterministic. There must not be an equation possible that could describe it. So then why is that incompatible with Star Trek style teleportation?
If there is no way to determine consciousness then there is no way to ensure whatever you have ‘copied’ is the same thing as what you are ‘pasting.’ You are indeed killing a person, then recreating their flesh suit in hopes ‘they’ go along with it. Without understanding consciousness better, which would require understanding (but clearly not being able to mathematically describe) a non-deterministic system, there would be no possible way to ensure this new creation of yours could ever be the same entity.