The naturalistic fallacy and Hume's ‘law’ are frequently appealed to for the purpose of drawing limits around the scope of scientific inquiry into ethics and morality. These two objections are shown to be without force. Thus two highly influential obstacles are removed from naturalizing ethics. The relative merits of moral skepticism and moral realism are compared. Moral skepticism and some forms of moral realism are shown to make similar recommendations for developing a science of moral psychology.