I think it’s more complicated than free will existing or not.

If you knew every single possible value about the universe at its start and had a perfectly accurate model of physics, you could theoretically predict/simulate everything that would ever happen. For practical reasons, though, that’s impossible, even ignoring weird quantum effects, for the simple reason that that is a lot of data points, more than any of us could reasonably keep track of- it’s like how, in sufficiently controlled conditions, a fair dice can roll the exact same number 100% of the time, but there are enough variables that are hard enough to control for in a normal situation that it’s basically random.

Similarly, if you knew everything about every human on Earth, you could theoretically predict exactly what any of them would do at any given moment. Of course, that’s just not practical- the body and brain are a machine that is constantly taking in input and adapting to it, so in order to perfectly predict someone’s thoughts and actions, you’d need to know every single detail of every single thing that has ever happened to them, no matter how small. Then, you’d need to account for the fact that they’re interacting with hundreds of other people, who are also constantly changing and adapting. It’s just not possible to predict or control a person for any reasonable length of time like that, because one tiny interaction could throw off the entire model.

Just look at current work with AI- our modern machine learning algorithms are much more well-understood and are trained in much more contained environments than any human mind, and yet we still need to manually reign them in and sift through the data to prevent them from going off the rails.

So, technically, I suppose free will doesn’t exist. For practical purposes, though, what we have is indistinguishable from free will, so there’s not much point getting riled up about it.

Well let’s start by examining the phrase “free will”

The term free has at least two different meanings in common language.

A) free as in beer ( free from cost) B) free as in speach (free from control)

Both of these could be broken down more (e.g. Monetary cost, entropic costs, mental cost and societal control, individual control, physical control… Etc)

Now, “will” is a bit more tricky. In this context we generally use it to mean “choice” However desire, and intention also get mentioned in the definitions.

1. desire
2. intention
3. choice

When commonly discussed I would say people tend to talk about B3(the ability to choose without external physical control)

I would argue 3 requires 2 which requires 1

So now we discuss B1 - are we free to pick our desires.

This I find to be interesting. We often see people desiring things which seem foolish. Foolish as is Unwise. What makes something foolish? Seems to me foolishness is caused by a lack of data and poor modeling.

At this point my phone battery is at 6% So I’ll cut my response short. I see no truly free will. I think our desires can be shaped over time via our input (previous choices) however we can’t roll a die and pick our desires.

I don’t think this is a bad thing. Just maybe not ideal but what is in this world?

Hard determinist here. It doesn’t make the future predictable by me, but I don’t see how randomness could really occur. And then likewise there’s no such thing as free will.

I have the feeling most people cling to free will as a concept because not having free will raises questions if a “self” truly exists. However the existence of free will can be as scary if not more, since how could we define a “self” if it could freely do something not based on what defines it.

Here is a good lecture from Robert Sapolsky on Human behavioral biology that will replace your question with more questions:
https://www.youtube.com/watch?v=NNnIGh9g6fA

Indeterministic + free-will doesn’t exist and can’t exist. You literally end in impossible contradictions if you entail its existence in a consistent universe (as in, one where everything that exists is subjected to the same natural laws).

As a side note for OP, Hisenberg has proven there’s no such thing as “knowing the initial condition”.

Quantum mechanics are probabilistic, which serves as a good argument for the universe as a whole being probabilistic. The position of a single particle could change a great many things!

You forget, the underpinnings of physics involve a heavy dose of randomness. Contrary to the opinion of a certain famous scientist, God does, in fact, play dice. Lots and lots of dice.

So no, the universe is not deterministic.

Note that this doesn’t mean free will exists. Your decisions may not be entirely predetermined, but them being determined by random chance doesn’t fit the definition of free will, either.

Deterministic with no actual free will, but complex enough that we’ll never be able to tell the difference. Essentially, our choices may technically be predetermined but for all intents and purposes, they are indistinguishable from free will and can’t be predicted.

I think the universe is deterministic, but also that absolute prediction is impossible and that there might even be actually random events in it (or not, I’m just not certain either way about that part). Even if you have an absolutely random uncalculatable die tho, that doesn’t mean the future is not predetermined. If hypothetically I had a time machine, rolled the die, recorded the result, and then went back to before it was rolled, then watched the roll again, then if it always gets that same result, despite not being “caused” by any external factors, then the universe would still be deterministic even with the presence of randomness

You react to choices the specific way you do because of experiences you’ve had previously.

Reverse time without changing anything, you’ll always make the same choices because you’re having the same thoughts each time every time, because you’ve been conditioned the way you are.

The universe doesn’t “know” where it’s going, but the plan is already in action. You can choose whatever you want to do, but if you were the same person in the same circumstance, you would and will always make the same decision.

The concept of belief is rooted in free will, is it not?

I live my life as if I have unlimited free will, and I view the world as if everyone else is fully determined by their circumstances. And then I just ignore the contradiction. Ez pz

I’d say free will exists. Sure, you are shaped by your environment, your genetics and so on, but in the end you can still decide what you want to do. In theory I could simply quit my job tomorrow, wander off into the sunset and then drown in the next ocean. Or as someone brought up criminals, you could stab someone just trying to disprove the universe is being deterministic.

If you know every single atom in this moment and had unlimited computing power, you’d probably be fantastic at telling the weather. Or if you map every neuron in someone’s brain you might know what they are about to do next. But at this point you are just looking at the present data and can maybe calculate the next few seconds (but not even that is 100% sure, just a very good guess).

The question is how far forward would you be able to look just based on current and past data? A minute? A day? A month? At that point the whole thing breaks apart in my opinion. It’s like looking at the stock market where you have tons of past data and think you can predict the future simply based on that.

There’s so many complex sources of randomness, the most likely solution is that things are just that, random. And you can decide what you want to do with your own life, at least until you die (or don’t, who knows what the future brings). Honestly the whole question is dumb, there is no single being that knows everything, so it really doesn’t matter. In the grand scheme of things even humanity is just a tiny blip on the timeline and we’re with very high probability not unique. Just based on numbers there is a high chance other life forms have existed before us, might exist right now with us (somewhere else in the universe I mean, there’s also plenty on Earth) and will exist in the future.