> But in fact, the only thing that privileges the set of all > computational operations that we see in nature, is that they are instantiated by > the laws of physics.
I would dispute this. The set of computable operations may also be privileged in that only a universe with laws of physics that instantiate all of these operations and none others can evolve intellegence (or alternatively these universes have the greatest chance of evolving intelligence). > It is only through our knowledge of the physical world > that we know of the di.erence between computable and not computable. So > it's only through our laws of physics that the nature of computation can be > understood. It can never be vice versa." So Deutsch is basically saying that we should not rule out the possibility that we may discover a new law of physics that will allow us to solve the halting problem, for example. I agree with this, given that we don't know that what I wrote above is actually true (instead of just a possibility).