Re: constructor paper - little criticism/query

On 21 Jan 2013, at 07:19, hibbsa <[email protected]> wrote:

> Hi DD, may I question what you say here in your first paragraph. :
> 
>> "Constructor theory seeks to express all fundamental scientific theories
>> in terms of a dichotomy between possible and impossible physical
>> transformations - those that can be caused to happen and those that
>> cannot. This is a departure from the prevailing conception of
>> fundamental physics which is to predict what will happen from initial
>> conditions and laws of motion."
> 
> I can see that you are taking things in a distinctive direction, but I'm
> not sure your characterizations above tease that distinctiveness out.
> 
> The dichotomy of possible vs impossible is deployed throughout science.

But not fundamental physics. That has, instead, the dichotomy between what happens and what doesn't.

> The naming/labeling differs but the purpose tends to be about
> identifying constraints. "Constraint oriented" methodologies are
> powerful....depending on how constrained something is, identifying what
> those constraints are go a long way to identifying what the 'something'
> is.
> 
> It does appear that your method is constraint oriented, in that you seek
> to constrain what things can be or do, by identifying what they cannot
> be, or do.

Constructor theory is not a method or a methodology but a theory about what the laws of physics, objectively, are. Laws that are deeper than currently known laws. The idea of 'constraints', and the possible-impossible dichotomy, and the idea of causation, and various classes of counterfactual statements, are all in common use in everyday life and in the applications of science. These are all, in my present view, examples of informal constructor-theoretic ideas. Yet they appear nowhere in laws of physics, and are notoriously difficult (the consensus has been that they are impossible) to reconcile with them.

-- David Deutsch