Disasters teach more than successes.

While that idea may sound paradoxical, it is widely accepted among engineers. They say grim lessons arise because the reasons for triumph in matters of technology are often arbitrary and invisible, whereas the cause of a particular failure can frequently be uncovered, documented and reworked to make improvements.

Disaster, in short, can become a spur to innovation.

There is no question that the trial-and-error process of building machines and industries has, over the centuries, resulted in the loss of much blood and many thousands of lives. It is not that failure is desirable, or that anyone hopes for or aims for a disaster. But failures, sometimes appalling, are inevitable, and given this fact, engineers say it pays to make good use of them to prevent future mistakes.

The result is that the technological feats that define the modern world are sometimes the result of events that some might wish to forget.

“It’s a great source of knowledge — and humbling, too — sometimes that’s necessary,” said Henry Petroski, a historian of engineering at Duke University and author of “Success Through Failure,” a 2006 book. “Nobody wants failures. But you also don’t want to let a good crisis go to waste.”

Now, experts say, that kind of analysis will probably improve the complex gear and procedures that companies use to drill for oil in increasingly deep waters. They say the catastrophic failure involving the Deepwater Horizon oil rig in the Gulf of Mexico on April 20 — which took 11 lives and started the worst offshore oil spill in United States history — will drive the technological progress.

“The industry knows it can’t have that happen again,” said David W. Fowler, a professor at the University of Texas, Austin, who teaches a course on forensic engineering. “It’s going to make sure history doesn’t repeat itself.”

One possible lesson of the disaster is the importance of improving blowout preventers — the devices atop wells that cut off gushing oil in emergencies. The preventer on the runaway well failed. Even before the disaster, the operators of many gulf rigs had switched to more advanced preventers, strengthening this last line of defense.

Of course, an alternative to improving a particular form of technology might be to discard it altogether as too risky or too damaging.

Abandoning offshore drilling is certainly one result that some environmentalists would push for — and not only because of potential disasters like the one in the gulf. They would rather see technologies that pump carbon into the atmosphere, threatening to speed global climate change, go extinct than evolve.

In London on June 22 at the World National Oil Companies Congress, protesters from Greenpeace interrupted an official from BP, the company that dug the runaway well. Planetary responsibility, a protestor shouted before being taken away, “means stopping the push for dangerous drilling in deep waters.”

The history of technology suggests that such an end is unlikely. Devices fall out of favor, but seldom if ever get abolished by design. The explosion of the Hindenburg showed the dangers of hydrogen as a lifting gas and resulted in new emphasis on helium, which is not flammable, rather than ending the reign of rigid airships. And engineering, by definition, is a problem-solving profession. Technology analysts say that constructive impulse, and its probable result for deep ocean drilling, is that innovation through failure analysis will make the wells safer, whatever the merits of reducing human reliance on oil. They hold that the BP disaster, like countless others, will ultimately inspire technological advance.

The sinking of the Titanic, the meltdown of the Chernobyl reactor in 1986, the collapse of the World Trade Center — all forced engineers to address what came to be seen as deadly flaws.

“Any engineering failure has a lot of lessons,” said Gary Halada, a professor at the State University of New York at Stony Brook who teaches a course called “Learning from Disaster.”

Design engineers say that, too frequently, the nature of their profession is to fly blind.

Eric H. Brown, a British engineer who developed aircraft during World War II and afterward taught at Imperial College London, candidly described the predicament. In a 1967 book, he called structural engineering “the art of molding materials we do not really understand into shapes we cannot really analyze, so as to withstand forces we cannot really assess, in such a way that the public does not really suspect.”

Among other things, Dr. Brown taught failure analysis.

Dr. Petroski, at Duke, writing in “Success Through Failure,” noted the innovative corollary. Failures, he said, “always teach us more than the successes about the design of things. And thus the failures often lead to redesigns — to new, improved things.”