As this anniversary loomed, we found ourselves asking: With all we now know, how to begin to address the enormity of the event? Our solution was not to shrink from its scale but to embrace it. With all we now know, how to begin to address the enormity of the event? In spite of its form, our encyclopedia makes no claim to be comprehensive. It’s neither a first draft of history nor a verdict—just a set of impressions from some point in between. September 11, 2001, changed everything, or it did not; it will take a lot more than ten years to figure that out.