Mark Twain must have had a good hammer, because he always struck the nail on the head and drove it deep. The quote informs us about what most know and a few won’t acknowledge, that we seem to inherently know right from wrong. Growing numbers of people are deciding they don’t need preachers and priests to inform them what’s good or bad, and Mr. Twain might remark about how the rest go to church because they need forgiven. Morality from induced fear will never outdo morality reasoned with a goal of rectitude; the former acts on emotions, which can become undone by stronger other emotions, whereas reasoned ideals deny emotional input from the start and so resist emotional input as much by habit as from anything else. Atheists shoot their own feet when they argue against their own morality as having anything to do with principles. It seems inherent to them, as do all good habits developed early on.