Ⅰ．Introduction: Moral Disagreements and Realism

“You should never lie, you can lie in some kill situations. You should one to save a hundred, you should not sacrifice one to save a hundred.Abortion should be allowed, abortion should not allowed...” Our life is full of moral disagreements. Many philosophers hope to explore ways to solve these disagreements and form a final agreement. There are many philosophers who doubt that this final agreement will never be realized or even it should not be realized.

Moral realism holds that there exists mind-independent moral truth,and advocates that people can solve all kinds of disagreements in today's world after discovering moral truth. On the contrary, moral relativism holds that there is no absolutely objective and universal moral truth or criterion,because morality itself is the product of different cultures adapting to its specific environment. For this reason, relativists believe that transcending the disagreements formed by cultural and social differences through a universal principle is doomed to fail.

The two theories have core difference in dealing with moral disagreements. On the one hand, moral relativism holds that moral diversity should be recognized, and different moral views may have incompatible parts. On the other hand, realists believe that by grasping the objective moral truth, human beings can finally find a solution to moral disagreements and form a final moral agreement.

This paper will first introduce Mackie's criticism of moral realism in the issue of moral disagreement. Then, it will reconstruct David O. Brink's objection of Mackie and point out that these objections pose challenges that relativists can't nespond to. Finally, this paper will evaluate Brink's scheme (especially the two exceptional conditions for the failure of moral agreement) and demonstrate that Brink's scheme will impose too strong argumentation obligation on moral realism.