Is moral knowledge possible? (Evaluation of Russ Shafer-Landau's critical view on error theory)

Defenders of the error theory believe that no moral knowledge can be found. They consider morality to be just a pleasant legend inherited from our ancestors. Russ Shafer-Landau a famous contemporary moral philosopher, believes that what the defenders of the error theory pursue is not only an attack on a specific moral point of view, but they seek to make the entire moral theory ineffective. According to Russ Shafer-Landau , the followers of the error theory to defend their claim must show that firstly, the acceptance of ethics depends on commitment to moral objectivity and the absoluteness of moral reasons, and secondly, even in the assumption that ethics is based on these two presuppositions, Less than one of these two assumptions is false.  In this article, by examining the strongest arguments against moral objectivity from Russ Shafer-Landau's point of view and revealing their ineffectiveness, we show that the arguments of the defenders of the error theory against objective morality are, at best and strongest, sterile, and therefore skepticism and the impossibility of knowledge Morality is not a correct view of morality.