The Objectivity of moral statements from Rawl's constructivist view and Hare's prescriptive view

In their meta-ethical views known as constructivism and prescriptivism respectively, John Rawls and Richard Mervin have criticized the traditional views toward objectivity from an anti-realistic position. Both thinkers reject the existence of the moral facts existing in the outside world independent of the moral subject; they are also against the intuitionism as a representative of this conception of objectivity. Yet, these two thinkers introduce themselves as the believers of the objectivity of moral principles. They believe that verifiability and falsifiability, universalizability, and the possibility of the moral reasoning are among the requirements of the objectivity in ethics and that their views meet such requirements. These requirements are fulfilled by the key functions of "impartiality'" and "justice" in Rawl's theory and by the emphasis on "putting oneself in other's position" in Hare's view. To avoid subjectivity, therefore, they argue for another conception of objectivity of which the characteristic feature is totality and generality originated from Kant's thoughts. These two views are anti-realistic, but Rawl's theory has the features of both cognitivism and descriptivism; unlike Hare who is anti-cognitivist and anti-descriptivist. The purpose of the present essay is the study of the similarities and differences of these two views to objectivity in ethics.