Second rules out cause though. If you have A=>B and B=>A as possibilities, and you can rule one of them out with a very simple question, that's a good way to st

Second rules out cause though. If you have A=>B and B=>A as possibilities, and you can rule one of them out with a very simple question, that's a good way to start. If computers came after electricity, they didn't cause electricity. That says nothing about the possibility of electricity causing computers, but it brings us forward nonetheless.