In defence of the open question argument

The purpose of this paper is to defend G. E. Moore's open question argument, understood as an argument directed against analytic reductionism, the view that moral properties are analytically reducible to non-moral properties. In the first section I revise Moore's argument in order to make it as plausible and resistant against objections as possible. In the following two sections I develop the argument further and defend it against the most prominent objections raised against it. The conclusion of my line of reasoning is that the open question argument offers the best explanation of our responses to the questions put in the argument, namely that analytic reductionism is mistaken.