Since yesterday afternoon, Americans have been waiting for the other shoe to drop. We know we’ve been attacked by someone deranged, hate-filled and cowardly, but we don’t know much more than that.The police seem to be following some leads, but either because no one is claiming responsibility or because so many are claiming responsibility we don’t know which species of loon is responsible for this horrible act. While a few of the usual suspects have beclowned themselves with premature and unfounded allegations, most of the media seems to have done pretty well at holding back from speculation about the identity of the attackers. A few have been unable to resist scoring political points by attributing the crime, without evidence, to whoever it is they hate most.Overall, the impression so far is that the American people are responding well to the dangers of the times we live in; as a people we seem to have grown since the shock of 9/11. The heartbreaking courage and spontaneous nobility of the bystanders and the first responders is still there; Americans still run toward a blast, seeking to help. Our social fabric is still strong; no looting, no random attacks on people whose clothing or appearance suggests a resemblance to the possible perpetrators. Ten years of insecurity and war haven’t eroded our core strengths as a people.Beyond that, we understand that the purpose of terrorists is to terrorize and to disrupt. We are braced for shocks now and we don’t intend to let the bad guys determine our response. Like the Israelis, like the Brits during the era of IRA bombings, like Iraqis turning out to vote in the face of the violence, we are getting on with our lives. “Keep calm and carry on,” counseled the Atlantic, echoing a slogan Londoners used during Hitler’s Blitz.We are a hardened people now, compared to the nation of civilians caught unaware on 9/11. We have lost the illusion that the 21st century will be a time without tragedy and testing. We know that any day can bring us this kind of news, and we have incorporated that reality into the way we think about the world.This knowledge has hardened us, but it hasn’t made us coarse. Though many criticized the response to 9/11 and some spoke of waves of “Islamophobia” sweeping the country, it’s notable in retrospect how open we have remained. The large majority of Americans are not idiots; they do not blame a peaceful majority for the acts of the twisted few. We have tightened security and while there are sometimes excesses and miscarriages (as there must inevitably be), on the whole we have so far done a reasonably good job of balancing the need for protection with the conservation of liberty.That is especially true when measured by the standards of past wars. Presidents Bush and Obama have been criticized by many for their allegedly draconian security policies, but Presidents Lincoln, Wilson and Franklin D. Roosevelt were almost infinitely more harsh in their responses to attacks. Not everything we have done has been well done or wise, and there are lessons to be learned from how we have reacted and improvements to be made in the protections for civil liberty in the face of danger, but for the most part, we have responded reasonably well to the challenge of protecting the people without squelching their freedom.At some point, this Schrödinger moment will come to an end; we will know who did this and why. A lone wacko? A conspiracy? A deranged right-wing nut job who somehow thinks killing innocent people on Patriot’s Day will strike a blow for freedom? A crazed religious fanatic who has mistaken hell-spawned hatred for the love of God? Some other fool carrying some other kind of hate?Amid our grief and sorrow over this attack, we should, I think, be grateful for the interval between the crime and politics. It allows us to treat the horror on its own terms, to see the pure evil of this act divorced from any rationalization or justification. A hater—of who or of what doesn’t matter—turned a festive public gathering into a bloodbath. Children with no possible connection to or responsibility for any political crime or provocation whatever have been mutilated and torn.The anonymity of the crime allows us to experience its enormity. Each hour that has gone by since the blast, each new report of heroism among the survivors and responders, each new detail about the identity of the victims clarifies the essential truth of the situation: there is no cause that can justify this deed.