 Along with providing this ideal limit to what we know, things outside the mind also stand as referents that themselves measure our cognitive assimilating. Recognizing that they exist, we also acknowledge that they are what our knowledge is about. And we constantly return to what we seek to understand to assess the adequacy of our conceptions and to correct any mistakes or misinterpretations in our interpretations. Deprived of these independent measures, our knowledge has no reference outside the mind and no standard for revising or improving our conceptual measures as more or less adequate to what we are trying to understand.