Error theory and expressivism are two forms of moral nihilism. Error theorists believe “our moral judgments are always mistaken”. (307) While expressivists deny those beliefs and deny, “that our moral claims can never offer an accurate take on reality”. (307) The error theory is made of three doubts/claims.
The first is “there are no moral features in this world”. Error theorists believe that nothing is morally good or bad, or right and wrong. Exemplified in the book many scientific qualities in the world (liquids, being three feet long, carbon based chemicals) but none of them contain moral features. The next doubt of error theorists is no moral judgments are true. There are no moral facts so certain statements made cannot be true. The third corresponds to the second doubt, “our sincere moral judgments try, but always fail, to describe the moral features of things”. Since there are no moral truths for moral decisions, all of our moral claims are mistaken. These three principles used by error theorists lead to the conclusion of no moral knowledge. The fourth claim counteracts and answers the third point. “There is no moral knowledge” when means knowledge requires truth. (307) If no moral truths are given there can be no moral knowledge.
Error theorists want it to be known that all moral thoughts are wrong. They believe that moral thoughts are not believable and people who believe in them are