Abstract
At least since the late Early Modern period, the Holy Grail of ethics, for many philosophers, has been to say how ethical values could have a kind of protagorean objectivity: values are to be both fully objective as values and yet depend on us by their very nature. More than any other contemporary foundational approach it is “constructivist” theories, such as those due to Rawls, Scanlon, and Korsgaard, which have consciously sought to explain how protagorean objectivity is a real possibility. Yet there remains considerable uncertainty about what the various versions of constructivism have in common, what, if anything, “constructivism” as a general approach is supposed to accomplish, and whether, if it is a general approach, it amounts to a distinctive foundational view.