That's a great point about the similarity of the two problems. If we didn't already know from intimate personal experience that there is such a thing as conscio

That's a great point about the similarity of the two problems. If we didn't already know from intimate personal experience that there is such a thing as consciousness, no amount of physical observation could ever be sufficient to prove to us that it exists. Similarly, if we weren't well prepared (on other grounds entirely) to assert that certain things ought or ought not to be done, no amount of observing the actual state of things could be sufficient to show that there is actually good or evil in the world.