On 8/4/2013 1:43 PM, Adam P. Goucher wrote:
David Makin wrote:
I disagree strongly., why are "Turing machines" obviously not consdcious ? Turing machines are mathematical concepts, not materialistic entities. When programmed correctly, they are capable of miraculously sophisticated behaviour -- probably greater than that of human minds, potentially, due to the unlimited storage -- but they can't possibly be conscious. Here is a thought experiment:
Suppose a Turing machine X with initial tape T_0 is `conscious'. Then, by definition of consciousness, it must be aware of its existence. Now, I suppose that cannot be ruled out in the following situation:
1. An electronic computer simulates X with the initial tape T_0, and is therefore conscious.
But the Platonic abstraction of `X with the initial tape T_0' has always existed as a mathematical abstraction, so even before anyone built an electronic computer it must have been conscious. Even before the universe existed, `X with the initial tape T_0' has always had a predetermined set of future states. Going in the other direction, what about the following?
2. Two electronic computers each simulate X with the initial tape T_0. Are you suggesting that the `consciousness' therefore inhabits both electronic computers simultaneously?
Finally, if Turing machines are conscious, then so are (by emulation) Diophantine equations.
Turing machines *with no method of sensing the outside world* may well be "obviously not conscious" but give the computer the programmed ability to self-evolve and sense the rest of existence - what then ? Suppose you give the computer a method of sensing the rest of existence. Without loss of generality, it may as well receive a binary input stream through a USB port (or whatever).
But, equivalently, we could write the same binary input stream on its initial tape, so this self-contained Turing machine behaves exactly the same as your `computer with a method of sensing the rest of existence'.
I think the correct inference is that "to be conscious" requires a an evnironment, something to interact with. Then for a Turing machine to be conscious it either has to be implemented physically in a world with some input-output, as in a robot. OR it could be simulating a whole world including as part of that conscious beings - and in that case it would not necessarily have to be physically realized. This is the theory of Bruno Marchal who claims to prove that the physical (and the mental) are both implicit in an abstract computation by a Universal Dovetailer. Brent