 Most arguments for moral error theory, however, presuppose that moral concepts do have a reasonably determinate content, but that there is simply nothing in the world to satisfy this content. The traditional form of argument for moral error theory, thus, has two steps. First, the error theorist undertakes the conceptual step of establishing that in participating in moral discourse we commit ourselves to the world being a certain way (that it contains certain instantiated properties, etc.). Then the error theorist undertakes the ontological step of establishing that the world is not that way. The latter may be achieved (in principle, at least) either through a priori means or through a posteriori methods.