If you think that a body which has survived, although just barely, Oliver L. North, can survive anything, the joint select committees on the Iran-contra scandal may have a little life left in them.

But after the lieutenant colonel had carpet-bombed the Senate Caucus Room with telegrams and flowers from an adoring public for six days, another of Reagan's military men, former national security adviser Rear Adm. John M. Poindexter, came in to mop up. He swore that he never told the president about the diversion of funds to the contras. By noontime Wednesday, citizens were calling up to demand the committees "stop wasting taxpayers' money" and shut up shop.

North was a shredder of dangerous White House documents. Poindexter was no slouch. He was a ripper. He tore up the embarrassing finding in which it is stated "without sufficient staff work" that the president was exchanging arms for hostages in Iran.

The old sea-dog was at heart an old pol. He deep-sixed the finding for political reasons. He said, when he was going through his souvenirs in anticipation of a "fact-finding visit" from the attorney general last November, "They will have a field day with this." The "they," of course, is the Congress and other petty people who were yowling that the president had exchanged arms for hostages.

The admiral was a much more restful witness than his rambunctious subordinate. He was wearing mufti, and he felt so relaxed that he lit up a pipe and was wreathed in aromatic clouds at the witness table.

The colonel, who treated the committees to his views on terrorism, foreign policy, congressional relations, marital fidelity and lying -- "it is not easy" -- left the Senate Caucus Room a smoking ruin. He had set House and Senate, Democrat and Republican, against each other, inspired procedural changes, precipitated criticism of Senate committee Chairman Daniel K. Inouye (D-Hawaii) and the committee counsels and inspired a flood of oratory during which the members tried passionately to prove that they were also Americans and patriots.

Inouye, whose behavior has been impeccable from the first day, was subject, Republican Vice Chairman Warren B. Rudman (N.H.) emotionally revealed, to ethnic slurs from people who found him insufficiently respectful of Mr. Wonderful.

Inouye made a moving speech about his combat experience -- he is a veteran of the 442nd combat team of Japanese Americans who were allowed to demonstrate their patriotism in battle and won more decorations than any unit in World War II. He has the Distinguished Service Cross.

He said he had voted against the contras because he hates war -- as he assumed his guest did. No one dares explain an anti-contra stand except in terms of the U.S. casualties that could result if we are drawn into combat. North so compellingly presented himself as someone who "lied to save lives" no one mentioned the 20,000 Nicaraguans who have died in the proxy war.

Inouye was proceeding in his rich bass so effectively that North's contentious lawyer, Brendan V. Sullivan Jr., stopped him in midstream.

Finally, mercifully, the fireball was gone, and the committee brought back a wet blanket. North's old boss, Robert C. McFarlane, former national security adviser, wanted to clear the record of North's smudges, although it was difficult to divine this from his turgid opening statement.

Sometime ago, McFarlane said that North was "rather like a son to me."

If so, North was like a teen-ager who is zooming down the driveway before he leans out the window and calls, "Mind if I take the car, Dad?"

His reports to poor McFarlane sounded like ultimatums. "Unless otherwise directed, I will proceed as follows," he ominously concluded.

McFarlane bore no ill will: "I don't think Col. North would make a deliberate misstatement or a lie."

North's more recent boss, Poindexter, is also a fan. The admiral wanted to recommend Ollie for special assistant to the president except they had to give cover to such a priceless asset.

Three of the people most likely to give the president the lethal news about the diversion say they didn't. And if you buy the idea that that's all we need to know, the hearings are finished. But the chances are that the committees, although Northed, will soldier on, because everyone, including the president, said they want to know how it all happened, and we're not there yet.