Re: Justificationism

On 31 Dec 2012, at 20:29, Anonymous Person <[email protected]> wrote:

> I don't understand this debate about Deutsch being a justificationist.
> Doesn't Deutsch openly declare himself in favor of justificationism in
> The Fabric of Reality?

David criticises justificationism is BoI. 

And in FoR he criticised the idea that knowledge rests on foundations, which is similar to justificationism.

> Here are some quotes:
> 
>> Most contemporary philosophers are crypto-inductivists. What makes matters worse is that (like many scientists) they grossly underrate the role of explanation in the scientific process. So do most Popperian anti-inductivists, who are thereby led to deny that there is any such thing as justification (even tentative justification). This opens up a new explanatory gap in their scheme of things.
> 
> In this passage, Deutsch says rejecting all justification creates an explanatory gap in the thinking of Popperian anti-inductivists.

The substance of his objection is not that the Popperian anti-inductivists don't explain the justification of knowledge but that they don't explain the growth of knowledge as an emergent part of physics. That's not a justificationist objection.

>> I believe that we can justify our expectation that the Floater would be killed. The justification (always tentative, of course) comes from the explanations provided by the relevant scientific theories. To the extent that those explanations are good, it is rationally justified to rely on the predictions of corresponding theories.
> 
> An additional point in this passage is that it mixes up the difference
> between justifying an idea and justifying a course of action. First it
> talks about "justify our expectation". Then "the justification". But
> then "it is rationally justified to rely on". An expectation is an
> idea, that first sentence is about justifying an idea. Relying is an
> action, the third sentence is about justifying an action. The middle
> sentence doesn't specify either way.
> 
> The Popperian anti-inductivists who reject all justification reject
> all justification *of ideas*, but this does not necessarily apply to
> other meanings of the word. Their position on justification is about
> epistemology, not actions.

To take an action you have to create knowledge about the results of your actions and how they are related to what you hope to accomplish. So epistemology is relevant to judging actions.

>> CRYPTO-INDUCTIVIST: Very interesting. I now understand the role of a theory's refuted rivals in the justification of its predictions.
> 
> This one is justification of ideas (predictions).
> 
>> DAVID: No. Our justification does not depend on whether a particular anomaly happens in the past. It has to do with whether there is an explanation for the existence of that anomaly.
> 
> and
> 
>> But if I were wrong about that, indeed even if we were entirely unable to explain this remarkable property of reality, that would not detract one jot from the justification of any scientific theory. For it would not make the explanations in such a theory one jot worse.
> 
> In The Fabric of Reality, Deutsch proposed explanation as the new
> criterion of justification. It's his replacement for induction.
> 
>> An analogous gap exists in Popperian epistemology. Its critics wonder why the scientific method works, or what justifies our reliance on the best scientific theories. [...] For Popperians to reply that there is no such thing as justification, or that it is never rational to rely on theories, is to provide no explanation.
> 
> Again, Deutsch presents himself as a critic of Popperian epistemology,
> and as intentionally rejecting the Popperian position on
> justification.

David's criticism of the idea of foundations in FoR applies with just as much force to particular arguments. The idea of explaining everything from foundations would leave the foundations unexplained. In an individual argument there can never be any possibility of proving the argument true or probably or anything like that. To say you had done that would be to leave out the possibility that you have made some assumption that you would have to discard if it was properly explained and that discarding this assumption would refute the argument. I think the logic of the anti-foundational argument in FoR implies that justification should be totally removed from all of our ideas about knowledge root and branch.

I don't think it would be necessary to make many changes to the ideas explained in David's books as a result of making that change. Many of the instances of the word 'justification' could be replaced with 'explanation' and the argument would be non-justificationist. Some instances of 'justification' in the books are in scare quotes and so they would remain the same since they are compatible with the complete rejection of justificationism. There is one instance that I know of that would have to be completely deleted. (The Hermes quote from BoI you posted in another message.)

Alan