The Cartesian approach is always very interesting in this regard. Consciousness implies at least some kind of self.

Out of curiosity:

1. In this case, do you believe consciousness encompasses the entirety of the person, as in the "I" that we can most certainly believe to exist (the one that sees, experiences, feels, etc.) is the same as the one that moves, acts, speaks, etc. and thus there is only one "self"?

2. As a follow-up, what do you think our existence consists of? Non-reductive physicalism, mind-body dualism, idealism, something else?

It's certainly a very interesting and possibly valid point that a person is not the same as just the collection of his cells... But then my question is what separates that person from said collection rather than being just a huge pile of complex cooperations between those cells in which the predetermined nature of everything just got a bit lost or impossible to perceive?

Of course I don’t think that we are the exact same thing as a single organic cell. From a certain point of view we are completely different thing (in fact a cell is not made up of billions of cells).

I was just trying to show that from another point of view, cells show complex behavior as a whole, but you wouldn’t say that the single cell has free will.

I like the analogy.

For all we know, our current state of brain analysis is a blind person sitting in a house, trying to figure out if it will rain tomorrow.

The task seems impossible, though an astute individual could possibly make some accurate prediction based on information that seems invisible to most. However impressive this skill, it would be nothing compared to modern meteorology and its vast array of thermometers, barometers, radars, satellites and dozens of other measuring tools. A few hundred years ago it would have been sorcery.

I think you underestimate the task. The possibility space of nonsense is so unimaginably huge, and the thing is, they don't matter one way or the other to your survival.

And what kind of data would you be looking at? Just to make sure you are not using an outcome to predict an outcome i.e., a tautological model.

Quantum mechanics point toward determinism not being possible. Not just that, but local realism is false; which means that either reality can travel faster than light,(locality is false) or that particles definitely do not have set values before observation (realism is false)

I personally suspect both to be false, but I am a geek and not an expert so don't take that as more than a hunch. But even if only realism turns out to be false, that is enough to dismantle determinism and, in my eyes, a strong case in favor of free will.

I think the first thing to accept is that we're 3-dimensionally bound beings, and we're still trying to figure out how to grasp the 4th dimension.

Best way to explain why 4D is tricky to grasp, is by going down a level in the comparison: pretend we're 2D beings trying to understand 3D.

If we're 2D beings, then that means we can perceive height and width, but not depth. That means you would be unable to see a sphere, but you would be able to see each 2D circle of it, if you were to slice the sphere into tiny cross sections.

Picture a sphere resting on a piece of paper. The flat circle it imprints on the paper would just be a dot. As you lower the sphere through the paper, the circle it leaves on the paper keeps getting bigger until you reach the middle of the sphere. At which point it will go back to being smaller again as you continue to lower it, eventually ending up back at the dot.

So while you can never actually see the entire sphere all at once for yourself, you would theoretically be able to infer the true nature of the sphere by stacking all these circles on top of each other. However the problem here is that you wouldn't even understand the concept of stacking the circles. The only thing you can perceive for yourself, is the 2D circle increasing and decreasing. It's difficult to try to imagine the sphere, when you've never seen a 3D object.

And it's even worse if a 1D being tries to grasp the sphere. They would only see a dot that grows into a line, which then shrinks back into the dot. To infer that you're looking at a sphere, you would have to take note of the fact that the line expands at a higher rate initially, only to eventually slow down in its growth until it stops. And actually, you don't have enough information available to you to actually conclude that it's a sphere. It could be a cylinder or cone lying on its side with the circle facing you, you'll never know.

So yeah, sorry if this seemed off-topic, but I just think the first thing to wrap your head around when trying to understand quantum physics is that our natural senses are limited. Things aren't supposed to make sense or feel intuitive, when you're punching a dimension above you.

To explain, quantum mechanics refer to the behaviors of particles, which work differently than large scale physics predicts. The most important aspect to this discussion is particles behaving differently when measured vs not measured. Light for example is a wave when not measured, and a particle when measured. The photons, before being measured, act as a wave becaue their values are not defined before measurement (or observation). This is the source of true randomness in the universe. Theoretically, you could predict the behaviors of anything in large scale physics by having the starting conditions. Quantum mechanics do not allow you to predict the future even with the starting conditions.

Since our brains are essentially quantum computers, it can not be claimed that our choices are pre-determined. This does not prove free will beyond a reasonable doubt, (randomness being involved in our decision does not entirely disprove the notion that our decision is just a mechanical process) but it is a very strong argument for free will because it at least contradicts the notion that everything that we choose is pre-determined by the starting conditions in a system.