Version 1 of #3884

I see why you would interpret the BoI quote in that way, but in the context of the whole philosophy your interpretation is implausible. It would go against Deutsch's own criticisms of justificationism (various chapters of BoI and FoR) as well as his criticisms of scientism – that is, the misapplication of scientific methods to philosophical problems (e.g. https://www.youtube.com/watch?app=desktop&v=tzWGfi4XhLA&t=7s).

Regardless of what Deutsch meant, though, the main point is that it's possible to talk about the virtues of explanations without falling into justificationism, for example when trying to explain progress.

I have made related points in #3883.