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Will computer models refute free will?


Tea With Laplace's Demon
Meet the seat of human consciousness.
Meet the seat of human consciousness.
Compassionate Eye Foundation/Chris Newton/OJO Images Ltd/Digital Vision/Getty Images

Let's return to the glowing box and to the far-seeing document within that accurately predicts every choice in your life. The supercomputer that authored these papers would essentially constitute a Laplace demon -- that theoretical intellect capable of predicting every event in the universe to such a degree that the possibility of individual free will appears impossible.

Is such a computer possible? We already use complex computer models to predict future weather conditions, though these become less reliable the further they reach into the future. There are simply so many variables, and our current level of computing technology is ill-equipped to replicate it. In fact, chaos theory itself arises from our scientific attempts to predict the weather. In many cases, the perceived chaos in a complex system doesn't mean that the system is patternless, but rather that the patterns are invisible to the naked eye, or even to human perception itself.

Still, the complexity of the universe -- like the weather -- compounds itself the further into the future you attempt to forecast. By some estimates, the movement of the planets would become unpredictable beyond the 100-million-year point [source: Laskar]. Even if such complex computation were technologically possible, it might prove physically impossible to carry out the computations in this universe [source: Deutsch]. You'd need a parallel universe just to house that supercomputer.

MIT computer scientist Scott Aaronson paints a more realistic model for computer-based refutation of free will. In 2011, Aaronson presented his "envelope argument" for the nonexistence of free will. It plays out as follows:

  1. An advanced, future computer analyzes your mind using actual and conceivable brain scan and DNA testing technology.
  2. This computer then creates an artificial model of your brain based on the collected data.
  3. Next, the computer makes predictions based on this model and seals them in an envelope.
  4. A scientist asks you a question and, after you answer, the person hands you the envelope. When you open it, you find that it contains the exact words that you just uttered to the scientist.

This scenario, Aaronson argues, would be as close to an "empirical refutation of free will" as we could possibly ask for.

But the case is far from closed. Associate professor Eddy Nahmias of Georgia State University's Neuroscience Institute argues that our concept of free will simply needs a reboot. If we view the mind as a product of a biological brain rather than a supernatural soul, he says, then we can come to terms with the limitations of our rationality, self-knowledge and self-control.

So it's not a matter of science explaining away the "magic" of consciousness, but rather merely one in which we come to understand the limited-but-existent roles of conscious deliberation and self-control in the biological process we call consciousness.

So step inside the box. Kneel beside the stack of papers on the floor. Leaf through the articles on the next page to learn all about science and other mysteries of the human brain.


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