There appears to be one level at which the ethical relativist can claim moral knowledge. Let's assume that when the relativist makes a moral judgment about an action it means that the action conforms to or violates a moral principle that applies to some individual or group. This is a simplified version of what Wong believes.

Now the judgment that the action conforms to a principle or violates it is usually a judgment about the facts pertaining to the action and the principle. We can know in an uncontroversial way that this is true or false.