tilthat: TIL a philosophy riddle from 1688 was recently solved. If a man born blind can feel the differences between shapes such as spheres and cubes, could he, if given the ability, distinguish those objects by sight alone? In 2003 five people had their sight restored though surgery, and, no they could not.
nentuaby: I love when apparently Deep questions turn out to have clear empirical answers.
Philosophy is vast. Some branches of it work with thought experiments that seem impossible to be tested/confirmed/solved or, at least, cannot be tested/confirmed/solved yet.
The brain in a vat may be confirmed someday, for example, if we indeed are living in such a situation and it is later revealed. Still, the problem behind would probably persist so I'd defend the thought experiment is useful. The one the post is talking about was impossible to test so it could only be speculated upon, but now it has been tested. Others are more elusive, like Mary's room or the dozens of ethical ones.