THE BOUNDARY ONE CANNOT LOCATE: Why No Description of the Physical World Can Be Certified Complete

The claim is narrow: nothing can certify that a description of the physical world is complete. To certify, here, is not to feel confident but to be in a position to assert --- to have established that nothing has been left out. So stated, the claim is no tautology; it rests on what a describer can reach. But its argument is short, and the work is in meeting the two ways of escaping it: the theorem, which promises another route to the answer, and convergence, which promises that no answer is needed. The first part of what follows takes up the theorem; nothing in it is a premise of the second.