Wonderful discussion. Philosophy can help a little on some of these questions; philosophers have come up with good arguments against silly problems they have created. 1. The "brain in a vat," the computer simulation, all-reality-is-in-my head-arguments, all presume something that is hard to imagine existing without a natural world, e.g. the brain, the vat, the computer and its software, my head, AND the publicly interpretable language used to MAKE the silly argument in the first place. 2. YES, it is true that, if A stands for "all human cognition" there is NO non-circular way for HUMANS to cognize that A is true of an independent world. But so what? There is no non-circular agrument that A is NOT partly or mostly true of an independent world. 3. In fact, there is fallible, imperfect evidence that our cognitive system, like that of my dog, was naturally selected to correspond to some features of nature. And that we, unlike my dog, can continually improve our cognition with collaborative inquiry. Naturalism doesn't need any more than that, once you drop the hopes for certainty and finality.
Wonderful discussion. Philosophy can help a little on some of these questions; philosophers have come up with good arguments against silly problems they have created. 1. The "brain in a vat," the computer simulation, all-reality-is-in-my head-arguments, all presume something that is hard to imagine existing without a natural world, e.g. the brain, the vat, the computer and its software, my head, AND the publicly interpretable language used to MAKE the silly argument in the first place. 2. YES, it is true that, if A stands for "all human cognition" there is NO non-circular way for HUMANS to cognize that A is true of an independent world. But so what? There is no non-circular agrument that A is NOT partly or mostly true of an independent world. 3. In fact, there is fallible, imperfect evidence that our cognitive system, like that of my dog, was naturally selected to correspond to some features of nature. And that we, unlike my dog, can continually improve our cognition with collaborative inquiry. Naturalism doesn't need any more than that, once you drop the hopes for certainty and finality.