Laplace's Demon and the Question of Free Will

Pierre-Simon Laplace was a French mathematician and physicist born in the mid 18th century who made enormous contributions to the development of the natural sciences. But he also made contributions to modern philosophy with his idea of causal determinism. Closely related to predeterminism, Laplace's ideas were rooted in scientific thought. 

In A Philosophical Essay on Probabilities, Laplace argued for scientific determinism in the following words:

"We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atoms; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes."

Sounds a lot like God, doesn't it? 

Simply, consider an atom; any atom, that is part of your body. Now, you go back in time, thousands, millions, and then billions of years. You watch that atom skip and jump through a series of events back to the singularity that resulted in the big bang. Now, press play. You see? Everything that has happened since is the result of a series of events that are a product of particles coming in contact with other particles in their vicinity. Thus, one might assume that knowing the position and quantum state of the particles in a space, their evolution in space-time is pre-determined. Neat.

Thinking about it, does this not negate the idea of free will? Does it not imply that everything we do is the result of a series of events that can be predicted based on the position and states of the particles that make us? It would require loads of computation, really. But since Laplace's demon can compute and predict the universe, we're possibly simple too. 

But there's one little problem. Werner Heisenberg, a brilliant theoretical physicist from Germany, introduced an idea called the 'Uncertainty Principle'. Simply put, the principle states that the position and velocity of a particle cannot be determined without disturbing the system when we observe it. The observer effect can be used to argue for the anthropic principle, but that's a story for another day.

Heisenberg's uncertainty seemed to yank the rug from under Laplace's Demon. Or did it?

Yes, quantum mechanics is fundamentally probabilistic and certainly uncertain. But, that has to do with the observer effect, right? What really goes on when we're not looking? Is there another set of rules that govern quantum particles when unobserved? We would never know. Does the Demon know of a way to observe the quantum particles without letting them know they're observed? We'll never know that, either.

Another stumbling rock in the Demon's path is what we call the Butterfly Effect, one of the central tenets of chaos theory. The smallest change in the initial state of a system will lead to an entirely different outcome. Tying in with the uncertainty, it sounds like the Demon has been exorcised for good.  Right? Although, I tend to differently.

What do I believe in? Well, belief is a strong word. But I do think that quantum particles behave entirely differently when unobserved, and if those laws are static, the universe is fundamentally predictable in its entirety. Simply, I am unsure whether we are ever in control of anything. I think time exists as a block, stretching from the big bang up to the end of the universe (if there is one). We merely exist to play our part in the play, living through the snapshots that make up time, snapshots that we call now.

Do you find the idea liberating? Knowing that whatever screw-ups you've had, were the result of a deterministic system? Or do you find it suffocating? Knowing that you're never in control. That you'll forever be a puppet in the hands of time and probability.