&gt; what is missing is an epistemological principle that tells us what our brains do to create true knowledge<p>Yes, I think even Deutsch would mostly agree with that, though I think his position would be: we know what the <i>principle</i> is (universal computation) but we don&#x27;t yet know the particular <i>mechanism</i> by which our brains produce new theories, and that when we do figure that out it will be a major breakthrough.<p>Anyway, thanks for clarifying.