BERLIN — Even in the nightmarish immediate aftermath of the plane crash in the French Alps on Tuesday, Carsten Spohr, the former pilot who runs Germany’s Lufthansa airline, was sure of one thing: the co-pilot, Andreas Lubitz, 27, was “100 percent” fit to fly.

Mr. Lubitz, after all, had been through the widely respected Lufthansa training system — “one of the best in the world,” Mr. Spohr said — and had met all other requirements to fly commercial aircraft.

In the decades since it emerged from the ruins of Nazism, this country — which reunited in 1990 and in recent years has dominated Europe as its economic powerhouse — has come to define itself as orderly, rule-driven and well-engineered. It is an identity that is both an antidote to its past and a blueprint for economic success. From Mercedes-Benz cars — “the best,” says a current ad campaign — to its countless tidy towns, Germany purrs excellence.

Now Mr. Lubitz — born and raised in one of those pretty towns — has upended that well-ordered world and challenged other assumptions built into German life. As Mr. Spohr noted, the co-pilot’s terrifying deed was a singular, perhaps unstoppable disaster. Yet somehow the system failed.

Any nation would be jolted. But this one raised questions distinct to Germany. In a society that prizes process, did the system lack the ability to spot warning signs that could have stopped Mr. Lubitz before he flew a jetliner into a mountainside, killing himself and 149 others? What, if any, responsibility should German society bear? And 70 years after the end of World War II, should Germans insist that protecting privacy trumps open debate that may help avoid the worst of human behavior?

The official response to the crash affirmed Germany’s decades-old trust in defining itself as one member of a European community. In January, Chancellor Angela Merkel leaned on the shoulder of President François Hollande of France, showing solidarity after the terrorist attacks in Paris. In this case, Ms. Merkel stood near the crash site with Mr. Hollande and the prime minister of Spain in a tableau of unity and shared grief.

But affected Germans showed a clear preference for sorting out the questions posed by events in their own way.

Writing from Montabaur, the Rhineland town of some 15,000 where Mr. Lubitz was born and raised, a journalist for the online edition of the respected weekly Die Zeit, Karsten Polke-Majewski, described the hostility of residents to prying questions and pondered the discomforts of self-examination.