 Even if the error theorist can articulate a clear and determinate problematic feature of morality, the dispute over whether this quality should count as a “non-negotiable component” of morality has a tendency to lead quickly to impasse, for there is no accepted methodology for deciding when a discourse is “centrally committed” to a given thesis. What is evidently needed is a workable model of the identity criteria for concepts (allowing us confidently to either affirm or deny such claims as “The concept of moral obligation is the concept of an objective requirement”)—but we have no such model, and there is no consensus even on what approximate shape such a model would take.