Ethan - The cognitive dissonance in trying to fathom this is a bit much for me. It's like trying to figure out what someone means by 'McCarthy was a communist' or 'Spencer was a church-going Anglican.' Best to let it pass.
LeGrande - This is what you said, "You can't observe an abstraction. So, you can't demonstrate "the theory of gravity" by dropping a rock,... Abstractions apprehended by the intellect must be verified or refuted by acts of the intellect: reason, judgement, etc." Clearly you are trying to simply apply reasoning alone.
Ethan - "It has to be verified by reason and observation. When you observe a rock falling, your eyes do not relate the inverse-square law to your brain. If it were so, there would be no need for Newton, or science for that matter."
LeGrande - Now we agree : )
Ethan - "In any case, if it can't be proven that God does not exist, why should anyone believe that God does not exist? It's not as if unprovability should make a proposition more plausible."
LeGrande - The burden of proof is not on the deniers, the burden of proof is on those who claim there is a God. If you claim to know a Leprechaun, would you expect anyone to believe you without your being able to provide some evidence that the Leprechaun exists? Or do you expect the skeptics to try and prove that the Leprechaun doesn't exist?
Ethan - "So? The point is that the history of science shows that this Popperian "falsification" business is nonsense. Newton's theory is still here and we both agree it was not disproved by what, if Popper's views had any merit, should have been falsifications."
LeGrande - That is because Einsteins equations are simply more precise than Newtons. Extending π from 3.14 to 3.1415 doesn't falsify the first three digits, it verifies the first three digits. Learning that π is an irrational number does change the conceptual framework though and that is why we laugh when legislatures occasionally try to change π to 3.
Einstein did falsify the conceptual framework that Newton had built in almost exactly the same way that the discovery that π is an irrational number destroyed its original framework. The basic equations remain valid, just not as precise. Future advances on Einsteins theory will simply be more precise and they will most probably destroy his conceptual framework.
I'm not sure why you disagree with this--it's merely common-sense to note that, with respect to theories, "verified", "refuted", and "demonstrated" are things which are decided at the the level of intellect. Your eyes do not make theoretical decisions for your brain. In seeing a rock fall, your eyes do not decide something about the theory of gravity and inform your brain about it. Rather, it's your reason-enabled brain that makes those decisions. If it were not so, a monkey would be able to "verify" Newton's theory of gravity, because a monkey can observe a rock falling just as well as you can.
Does it really make sense to say that Newton's theory of gravity can be "verified" or "demonstrated" by dropping a rock and observing that it falls? If so, then Newton could have avoided the laborious route involving the invention of calculus and so on, and instead he could have thrown rocks up in the air a thousand times over. Others, observing this, would have to say that his theory of gravity has been demonstrated and verified a thousand times over. Any monkeys who happen to be there would add their howls of approval too.