Feeds

Deploying Turing to see if we have free will

I'm sorry, Dave ...

  • alert
  • submit to reddit

Security for virtualized datacentres

Alan Turing didn't just lay the theoretical basis for modern computing and save Britain in World War Two by defeating German cryptography: one of his problems also provides a theoretical basis for understanding free will, according to MIT quantum theorist Seth Lloyd.

Given the number of biologists – particularly in the neurosciences – that have decided humans don't have free will, it's an interesting idea. The nub of Lloyd's idea is in this passage: “decision-making systems … can not in general predict the outcome of their decision-making process”.

That means, he writes in this paper on Arxiv, that: “The inability of the decider to predict her decision beforehand holds whether the decision-making process is deterministic or not”.

So where does Turing come into the picture? Via what's known as the “halting problem”, which is stated on Wikipedia as “given a description of an arbitrary computer program, decide whether the program finishes running or continues to run forever”. Turing proved that no generalM algorithm exists to prove the problem, for all programs and all program input pairs.

The same, Lloyd argues, can even apply to human decision making:

“when a decider that uses recursive reasoning to arrive at a decision then

  • (a) No general technique exists to determine whether or not the decider will come to a decision at all (the halting problem).
  • (b) If the decider is time-limited, then any general technique for determining the decider’s decision must sometimes take longer than the decider herself.
  • (c) A computationally universal decider can not answer all questions about her future behavior.
  • (d) A time-limited computationally universal decider takes longer to simulate her decision making process than it takes her to perform that process directly.

The process of recursive reasoning, Lloyd argues, is something which in theory could be simulated by a computer – even though simulating an entire human is somewhat beyond computer science today.

Because the decision-making process can be simulated, he says, a Turing test can be contrived to answer the question “do I have free will?”

  • Am I a decider? (Even a thermostat counts as a decider);
  • Do I make my decisions using recursive reasoning? (Can some kind of Turing machine, even if it's beyond today's technology, be theorised that would model the decision-making?)
  • Can I model and simulate – at least partially – my own behavior and that of other deciders?
  • Can I predict my own decisions beforehand?

The last question, Lloyd notes, is something of a trick question: if you answered yes to all four questions, your answer to the last question is a lie; if you answer “yes, yes, yes and no”, then “you are likely to believe you have free will”.

And now that free-will advocates are tossing their hats in the air, Lloyd has a kicker downside of his Turing test: “Indeed, as computers and operating systems become more powerful, they become unpredictable – even imperious – in ways that are all too human.”

In other words, if a computer or even an iPhone answered the four questions the right way, as it probably would, then it would believe it has just as much decision-making free will as you have. ®

Internet Security Threat Report 2014

More from The Register

next story
SECRET U.S. 'SPACE WARPLANE' set to return from SPY MISSION
Robot minishuttle X-37B returns after almost 2 years in orbit
LOHAN crash lands on CNN
Overflies Die Welt en route to lively US news vid
'Utter killjoy Reg hacks have NEVER BEEN LAID', writes a fan
'Shuddit, smarty pants!' Some readers reacted badly to our last Doctor Who review ...
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
White LED lies: It's great, but Nobel physics prize-winning great?
How artificial lighting could offer an artificial promise
NASA eyeballs SOLAR HEAT BOMBS, MINI-TORNADOES and NANOFLARES on Sun
Astro boffins probe fiery star's hidden depths
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Win a year’s supply of chocolate
There is no techie angle to this competition so we're not going to pretend there is, but everyone loves chocolate so who cares.
Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.