Jonas Olson's Evidence for Moral Error Theory

Jonas Olson defends a moral error theory in 2014. I first argue that Olson is not justified in believing the error theory as opposed to moral nonnaturalism in his own opinion. I then argue that Olson is not justified in believing the error theory as opposed to moral contextualism either (although the latter is not a matter of his own opinion). I conclude that Olson has not given us quite enough evidence for moral error theory.