It was the question his handful of young students had learned to expect from him. He asked it of us every time we’d finished translating that day’s Scripture or a commentary on it.

He taught without an ounce of flash, Rabbi Leo Brener did, taking care to neither add to nor detract from the text. He left the flights of fancy to us. We found him terribly dull. At the time.

Only later, looking back, would we come to cherish the way he would pause before answering any question about the text. We got the message: This is Important. Not something to be entered upon lightly.

He never delivered any explicit sermon against the gods of the outside world – success, power, status – but we came to understand that they were of a lesser order. The message was implicit in everything he did. He moved with intention, the way he walked to and from the synagogue every Sabbath and holiday. Briskly, every step definite. With a purpose. So was his inevitable question: “What have we learned from this?”

History is a kind of scripture, too. And it, too, is to be examined carefully. It, too, changes with every reading. For history is not to be the confused with the past; it is what we make of the past. Each rereading, each rewriting, of that past casts a new light on it. Or a new darkness, depending on what the present chooses to remember, or chooses to forget.

History turns out to be the most contemporary of arts, reflecting the time in which it is written more faithfully than the time it describes. Leopold von Ranke’s ideal of a “scientific” history that would describe the past wie es eigentlich gewesen – just as it actually was – was always a delusion. For time is so constructed that we cannot escape our own era, its prejudices and predilections. For good or ill.

Ten years after September 11, 2001, what have we learned from that awful day – and the intervening years of triumph and tragedy, victories and defeats? Some old lessons must be learned anew: Eternal vigilance is the price of liberty. United we stand, divided we fall. Rabid personal attacks on the president of the United States and commander-in-chief of its armed forces, whether George W. Bush or Barack Obama, will only divide us. And weaken us.

A host of new lessons still wait to be absorbed. Among them:

–War is no longer a matter just between states. It can be waged against us by a shadowy enemy with no state, and no respect for the laws of war that states were once bound by. They must be pursued to the ends of the earth – and will be. See the fate of one Osama bin Laden, now consigned appropriately enough to the murky depths.

–Things should be called by their right names. Terror, terror and crimes crimes. We are not engaged in “overseas contingency operations” but a war against terrorism and terrorists. What happened September 11, 2011, was not an “unfortunate event” but an act of premeditated, unlawful war against the United States of America and its people. And we will not rest till justice is done.

–Despite the euphoria unleashed by the end of the Cold War, we have not moved into some idyllic “world warmed by the sunshine of freedom” (Bill Clinton) or “a world quite different from the one we’ve known” (George W. Bush). Whatever one superbly foolish historian announced at the time, history has not ended in the sure triumph of Western-style democracy. Any more than the human struggle for freedom will end.

September 11, 2011, was one of those days that changed everything, or should have. It was one of those dates that divide history into Before and After, like December 7, 1941. “All of this was brought upon us in a single day, and night fell on a different world, a world where freedom itself is under attack.” –George W. Bush, September 20, 2001. That day should have eliminated the petty from our politics, our thoughts, our abiding Union. But even while we remember it, we forget. We shouldn’t. That much we should have learned from all this.

© 2011 TRIBUNE MEDIA SERVICES, INC.