Monday, October 14, 2013

Lloyd gives opinion on free will

MIT professor Seth Lloyd just posted his opinions on free will with A Turing test for free will. But he goes wrong in his discussion of quantum mechanics:
Moreover, one of the central questions of free will – Is the universe deterministic or probabilistic? – is a scientific one whose answer lies at the foundations of physics. ...
No, it is not a scientific one. There is no theory or experiment that can resolve the issue, and there never will be.
From Newton up to the twentieth century, the philosophical debate over free will by and large assumed that the world is deterministic. In such a deterministic world, there are two antagonistic philosophical positions [3]. Incompatibilism claims that free will is incompatible with a deterministic world: since all events, including our decisions, were determined long ago, there is no space for freedom in our choices. Compatibilism, by contrast, asserts that free will is compatible with a derministic [sic] world.
This is the Standard argument against free will.
In contrast to classical mechanics, the theory of quantum mechanics that emerged as the fundamental physical framework at the beginning of the twentieth cnetury [sic] predicts that the world is intrinsically probabilistic. Despite Einstein’s opinion that ‘God does not play dice,’ experiment and theory have repeatedly confirmed the probabilistic nature of events in quantum mechanics. For example, the Kochen-Specher theorem [18] shows that certain types of deterministic hidden-variable theories are incompatible with the predictions of quantum mechanics, a result extended by the Conway-Kochen ‘free will theorem’ [19].
No, the theory of quantum mechanics does not predict that the world is intrinsically probabilistic. The fallacious reasoning is that deterministic hidden variable methods do not work, so the world is not deterministic. But the non-deterministic (probabilistic) hidden variables do not work either, so the conclusion does not follow. Attempts to prove randomness have failed. A recent survey found that 64% of physicists believe that randomness is a fundamental concept in nature, but that is just an unproven belief.

Not that Lloyd is alone. Today's NY Times article starts:
Quantum theory tells us that the world is a product of an infinite number of random events. Buddhism teaches us that nothing happens without a cause, trapping the universe in an unending karmic cycle.

Reconciling the two might seem as challenging as trying to explain the Higgs boson to a kindergarten class.
No, quantum theory does not teach that. And there is no evidence that anything ever happens without a cause.

None of this resolves whether or not we have free will.


  1. Is not causality the foundation of science, hence physics? If the universe were truly random, no one would be here to make note of it. I notice that many in the sciences believe that if they do not know the cause of something, there is no cause, it must be a random event. A little humility could fix this logical fallacy.

  2. Yes, causality is at the foundation of science.