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Old 05-22-2019, 01:28 PM
Half Man Half Wit's Avatar
Half Man Half Wit is offline
Join Date: Jun 2007
Posts: 6,823
Originally Posted by begbert2 View Post
Then you're not speaking english.

And seriously, the fact that you have repeatedly refrained from responding to the fact that your argument disproves your own mind seems telling to me
I didn't, because there is no way, shape or form in which anybody could interpret my argument as having any such implication.

So fine, one last time:
  1. Computationalism requires that, in order to give rise to a mind M, a brain B needs to implement a certain computation CM.
  2. A brain is a physical system.
  3. A computation is a formal object that we can take to be, without loss of generality, defined by a partial function over natural numbers (a definition that is equivalent to the one via Turing machines).
  4. B must implement CM in an objective, mind-independent way, as otherwise, whether or not B implements CM depends on whether B implements CM, and we lapse into vicious circularity.
  5. Binary addition is such a function. So is my function f'.
  6. In order for B to implement CM, it must more broadly be possible for a given physical system D to implement some certain computation C.
  7. Implementing a computation C by means of D entails that one can use D to compute C (just as, for example, one uses a pocket calculator to calculate, or a chess computer to compute chess moves).
  8. It is possible to specify a system D such that one can use it to implement f (binary addition) and f'.
  9. f and f' are distinct computations (follows from the definition of computation above: they're different functions over the natural numbers).
  10. The difference between D implementing f and D implementing f' is one of interpretation: the states of D, or aspects thereof, are interpreted as symbolic vehicles whose semantic content pertains to the formal specification of either f or f'.
  11. The process applied to use D as implementing both f and f' is completely general, and can be performed on every system claimed to perform some computation C in order to use it to compute C'.
  12. Interpretation is a mental faculty (as in, a faculty our minds do have, not a property that necessarily only minds can have).
  13. Whether a system D implements a computation is thus dependent on mental faculties.
  14. All mental faculties, on computationalism, are due to some computation CM.
  15. Whether D implements a computation is thus due to the particulars of CM.
  16. By specification, whether B implements CM is thus due to the particulars of CM.
  17. Hence, computationalism lapses into vicious circularity.

There. I hope that makes things clear. It should, in particular, be obvious now that nothing about the impossible of minds in general is implied; merely, that minds, which clearly do exist, are not computational in nature, that is, are not produced by the brain implementing a certain computation.

Now, I believe you won't give up on the 'but CM just interprets itself'-issue so easily. In that case, I have good news for you, because you can prove the existence of god!

For, god is an omnipotent being. Omnipotence entails the possibility to create gods. Consequently, god may just create him/hir/herself. And that's it!

Logically, this is perfectly analogous to CM interpreting B as computing CM.

Last edited by Half Man Half Wit; 05-22-2019 at 01:31 PM.